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Influence of Soil Organic Matter Content on the Responsiveness of Eucalyptus grandis to Nitrogen Fertiliser

Item type: Journal Article • Journal: South African Forestry Journal • Authors: A.D. Noble --- Institute for Commercial Forestry Research, South Africa M.A. Herbert --- Institute for Commercial Forestry Research, South Africa

It is widely recognised that the inherent nitrogen (N) mineralisation capacity of a soil is directly related to the organic matter content. Consequently, in estimating the N requirements of Eucalyptus grandis at planting this mineralisation potential must be taken into...

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The Amelioration of Pinus patula Mortality on Former Agricultural Sites through Fertilisation: A Bioassay and Greenhouse Study

Item type: Journal Article • Journal: South African Forestry Journal • Authors: A.D. Noble --- , South Africa A.W. Schumann --- , South Africa

Recent expansion of the timber industry into areas previously used for agronomic production has, in many cases, resulted in poor growth of Pinus patula and P. elliottii seedlings and in certain instances complete stand failure. A bioassay study was initiated...

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The effect of nitrogen on the development and photosynthetic activity of digitaria eriantha steud. subsp. eriantha

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: MaureenM. Wolfson --- Department of Botany, C.F. Cresswell --- Department of Botany,

Digitaria eriantha Steud. subsp. eriantha, plants were grown under controlled conditions and treated with different concentrations and forms of nitrogen. The plants showed a preference for nitrate nitrogen, as opposed to ammonium nitrogen, with greater total dry matter production and...

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The production potential of pure and mixed stands of Eragrostis curvula and Medicago sativa on the eastern transvaal highveld

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: N.F.G. Rethman --- Department of Agriculture (Transvaal Region), C.C. De Witt --- Department of Agriculture (Transvaal Region),

Over a five year period pure stands of Medicago sativa and mixtures of M. sativa and Eragrostis curvula have done as well and better than E. curvula receiving 300 kg N/ha, and considerably better than treatments receiving 200 and 100...

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The influence of different forms and concentrations of nitrogen on the growth and metabolism of digitaria eriantha and chloris Gayana grown under saline conditions

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: J M Brauer --- Department of Botany, MaureenM Wolfson --- Department of Botany,

Chloris gayana and Digitaria eriantha plants were watered with nutrient media containing a high concentration of sodium chloride (150 mM) and either high (200 mg/l) or low (25 mg/l) concentrations of nitrate nitrogen and ammonium nitrogen. Dry mass and leaf...

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Fertilization of southern tall grassveld of natal: Effects on botanical composition and utilization under grazing

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: G.R. Barnes --- Department of Grassland Science, D.I. Bransby --- Department of Grassland Science, N.M. Tainton --- Department of Grassland Science,

The long‐term effects of nitrogen, phosphate and lime on change in botanical composition and utilization under grazing of Southern Tall Grassveld of Natal are presented. Nitrogen, phosphate, lime and type of nitrogen affected botanical composition significantly. Generally, fertilization had the...

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Identification of companion legumes for midmar Italian ryegrass

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: H.R.H. Smith --- Department of Agriculture (Transvaal Region),

In a preliminary investigation seven legumes were planted alone and in combination with Lolium multiflorum cv. Midmar. The pure stands of legumes were harvested at either four, five or six week cutting intervals, while the pure stands of Lolium multiflorum...

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The effect of form and level of nitrogen fertlization on the yield of Digitaria eriantha Steud*

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: N.F.G. Rethman --- Department of Plant Production,

On dryland Digitaria eriantha ammonium sulphate and limestone ammonium nitrate were superior to potassium nitrate and urea. With reference to the level of nitrogen fertilization it was found that levels in excess of 300 kg N/ha, and up to 400...

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Fertilizer requirements and production of Anthephora pubescens nees on a soil of the mangano series in the northern cape

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: J.H. Fourie --- Department of Agriculture and Water Supply, L.G. Du Pisani --- Department of Agriculture and Water Supply, C.H. Donaldson --- Department of Agriculture and Water Supply,

The reaction of Anthephora pubescens to N, P and K fertilization was evaluated from 1976 to 1983. Dry matter production at N levels of 0; 75 and 150 kg/ha were 1,9; 2,2 and 2,3 ton/ha respectively. This relative poor reaction...

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Die produksie van smutsvingergras in die wes‐transvaal¹

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: C.S. Dannhauser --- Departement Landbou en Watervoorsiening, W.L.J. van Rensburg --- , D.P.J. Opperman --- , P.J. Vanrooyen --- ,

Die produksie van Smutsvingergras (Digitaria eriantha) is in yerskeie proewe in die Hoëveldstreek, op Potchefstroom, in die verlede bepaal. Hierdie proewe is oor ‘n lang periode op verskillende grondsoorte en met verskillende bemestingspeile uitge‐voer. Alle resultate is saamgevoeg en met...

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Identification of companion small grains for midmar Italian ryegrass

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: H.R.H. Smith --- , C.P. Dempsy --- Department of Agriculture (Transvaal Region), M. Schaffner --- Department of Agriculture (Transvaal Region),

In a preliminary investigation four small grain species, oats (Avena sativa), rye (Secalae cereale), wheat (Triticum aestivum) and triticale (Triticum × secalae) were planted alone and in combination with Lolium multiflorum cv Midmar under irrigation. The dry matter (DM) yield...

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The use of near infra‐red reflectance spectroscopy for the determination of plant nitrogen

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: R.J. Eckard --- Department of Grassland Science, N. Miles --- Department of Grassland Science, N.M. Tainton --- Department of Grassland Science,

A Near Infra‐Red Reflectance Spectrophotometer was calibrated to analyse Italian ryegrass for protein nitrogen (N). Rye‐grass samples having a wide range in N content were analysed by standard “wet” chemistry techniques and the resulting data used to calibrate the Near...

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The influence of nitrate and ammonium forms of nitrogen fertilizer on the growth and osmoregulation of digitaria eriantha and Chloris gayana grown under saline conditions

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: LesleyJ. Gray --- Department of Botany, MaureenM. Wolfson --- Department of Botany,

Digltaria eriantha and Chloris gayana were grown under controlled conditions for three months and were treated with a nutrient solution containing 150 mMol NaCl and the following nitrogen sources: 25 or 200 mg/l NH4 +‐N or NO3 −‐N or no...

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The response of Italian ryegrass to applied nitrogen in the natal midlands

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: R.J. Eckard --- Department of Agriculture and Water Supply (Natal Region),

Nitrogen (N) fertilizer was applied to irrigated Italian ryegrass (Lolium multiflorum cv Midmar) pastures at varying rates over two seasons on three sites. Soils series on these sites were Metz, Griffin and Katspruit. Total N application rates ranged from zero...

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Some effects of termitaria on veld in the eastern Cape

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: T.D. Steinke --- Department of Botany, Republic of South Africa L.O. Nel --- Department of Agriculture (Eastern Cape Region), Republic of South Africa

A survey was conducted to determine some effects of termite mounds on the veld. Termitaria were found to occupy approximately 0,4% of the area of the paddock under investigation. Growth of grasses immediately surrounding intact termitaria increased as shown by...

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Influence of phosphatic fertilization on the yield and chemical composition of grass pasture

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: N.F.G. Rethman --- Department of Agriculture & Water Supply, Republic of South Africa B.H. Beukes --- Department of Agriculture & Water Supply, Republic of South Africa

While the distribution of P fertilizer had an insignificant influence on the DM production of a grass pasture over a three‐year period, the level of both N and P was highly significant. Growth patterns were unaffected by any of the...

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Die invloed van bemesting op die spesiesamestelling en basale bedekking van beweide veld in die Potchefstroom‐omgewing

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: FranciP. Janse van Rensburg --- Departement Landbou en Watervoorsiening, Republiek van Suid‐Afrika R.H. Drewes --- Departement Landbou en Watervoorsiening, Republiek van Suid‐Afrika J.W. Cilliers --- Departement Landbou en Watervoorsiening, Republiek van Suid‐Afrika A.C. Beckerling --- Departement Landbou en Watervoorsiening, Republiek van Suid‐Afrika

The impact of fertilization on veld in the Potchefstroom area was investigated. Nitrogen and phosphorus were applied annually from 1972/73 until 1981/82. The control plots and the fertilized plots were grazed with year‐old steers. Species composition and basal cover were...

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Influence of temperature and growth stage on the diurnal fluctuation in the non‐structural carbohydrate content of kikuyu (Pennisetum clandestinum Hochst)

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: J.P. Marais --- , Republic of South Africa D.L. Figenschou --- , Republic of South Africa

The non‐structural carbohydrates of kikuyu (Pennisetum clandestinum Hochst) seem to consist mainly of sucrose. Total non‐structural carbohydrate content increased rapidly during the morning and reached maximum concentration in the afternoon. After sunset, the concentration decreased rapidly, reaching a minimum level...

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Relations between soil factors and herbage yields of natural grassland on sandy soils in the south‐eastern Transvaal

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: D.L. Barnes --- Department of Agricultural Development (Transvaal Region), Republic of South Africa M. Swart --- Department of Agricultural Development (Transvaal Region), Republic of South Africa M.F. Smith --- , Republic of South Africa G.H. Wiltshire --- , Republic of South Africa

Forty systematically‐placed observation points were established in a 1.5‐ha area of floristically unifoim veld in which productivity varied spatially. At each point grass yields were determined by harvesting quadrats at eight‐week intervals during the growing season, and the volumetric water...

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Utilization of Lolium multiflorum by sheep 2. The effect of drying the herbage on soluble nitrogen content and partial digestion

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: MarianaM. du Preez --- Department of Livestock Science, Republic of South Africa H.H. Meissner --- Department of Livestock Science, Republic of South Africa

The amount of soluble N and the effective degradation of fresh and dry herbage of Lolium multiflorum cv. Midmar (ryegrass) was determined by the nylon bag technique. In another experiment the digestion and disappearance of organic matter (OM) and nitrogen...

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Defoliation effects on resource allocation in Arizona cottontop (Digitaria californica) and Lehmann lovegrass (Eragrostis lehmanniana)

Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: JerryR. Cox --- , Republic of South Africa M. Giner‐Mendoza --- , Mexico A.K. Dobrenz --- Plant Sciences Department, United States of America MarieF. Smith --- , Republic of South Africa

Arizona cottontop (Digitaria californica), a bunchgrass native to the Chihuahuan and Sonoran Deserts in North America, and Lehmann lovegrass (Eragrostis lehmanniana), a bunchgrass introduced to the southwestern USA from southern Africa, were defoliated and examined for above‐ and below‐ground productivity,...

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Nitrogen fertilization of cabbages in Natal

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: T. Richards --- Department of Horticultural Science, I.E. Smith --- Department of Horticultural Science, R. Bennett --- Department of Horticultural Science,

Cabbage (Brassica oleracea var. capitata f. alba cv. Gloria Osena) yields were measured in two experiments on a Westleigh soil near Pietermaritzburg in response to different methods, rates and times of application of nitrogen fertilizer.

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Growth and production of Vicia dasycarpa Ten., Namoi as influenced by an oat support crop and nitrogen fertilizer

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: V.D. Wassermann --- Rietondale Research Station, Gillian Heyns --- Rietondale Research Station, A.J. Kruger --- Rietondale Research Station,

The performance of Vicia dasycarpa cv. Namoi in pure stand and mixed with oats at four densities, grown at three levels of N fertilizer, was studied in the field under irrigation. Both the increased plant density of oats and N...

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Reaction of oriental tobacco to spacing and topping treatments at three levels of nitrogenous fertilizer application

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.P. Lamprecht --- , W. J.C. van der Merwe --- ,

Three levels of nitrogenous fertilizer were applied to oriental tobacco (Nicotiana tabacum L. cv. Elcatra) at different spacings and topped to 14 and 28 leaves per plant respectively. Yield, income, total nitrogen and total alkaloids of the cured leaves increased,...

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Die invloed van fosfor, nitraat en ammonium op die opname en vervoer van stikstof en fosfor en op die groei van koring

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.S. Claassens --- Departement Grondkunde en Plantvoeding, W.J. Fölscher --- Departement Grondkunde en Plantvoeding,

In 'n waterkultuureksperiment met koring is die invloed van verskillende P-toedienings (0,02 tot 5,0 me H2PO4 dm−3) en van verskillende NH4:NO3-verhoudings (0:15 tot 12:3) met 'n Hoagland-voedingsoplossing (no. 2) as kontrole bestudeer. Normale groei is reeds by 'n laer P-voorsiening...

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A comparison of several nitrogen- availability indices on four Natal maize-producing soils

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: B.L. Schroeder --- , Republic of South Africa M. P.W. Farina --- , Republic of South Africa M.V. Fey --- Department of Soil Science and Agrometeorology, Republic of South Africa

Four methods used in obtaining nitrogen-availability indices were compared using soil and plant samples taken from maize trials conducted on four widely differing Natal soils. NO3 − N was determined after extraction of the soil with NH4HCO3, Ca(OH)2 and KCl,...

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Invloed van bemesting op die oliekonsentrasie oliekwaliteit van sonneblomsaad

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: H.L. Loubser --- Olie- en Proteïensadesentrum, Departement Landbou en Watervoorsiening, C.L. Grimbeek --- Olie- en Proteïensadesentrum, Departement Landbou en Watervoorsiening,

Influence of fertilization on the oil concentration and oil quality of sunflower seed. Fertilizer trials (N,P,K and lime) were conducted over two seasons at three localities. Results indicate that 150 kg N ha−1 fertilizer decreased the oil concentration of the...

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A proposed mechanism for the volatilization of ammonia from fertilized neutral to alkaline soils

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.C. du Preez --- Department of Soil Science, R. du T. Burger --- Department of Soil Science,

Ammonia volatilization from five soils, ranging in clay content from 7,6 to 49,9%, were determined after pH values of the soils were adjusted to 8,0. Ammonium sulphate, limestone ammonium nitrate, urea, monoammonium phosphate and diammonium phosphate were applied on the...

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Die rol wat nitraat: ammoniumverhoudings speel in die effektiewe benutting van stikstof by Zea mays L.

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: F.G. Adriaanse --- , J.J. Human --- Departement Agronomie,

Die invloed van verskillende nitraat: ammoniumverhoudings by sub- en supra-optimale stikstofkonsentrasies op die opname en benutting van stikstof is ondersoek. Effektiewe stikstofbenutting is in terme van saadopbrengs per eenheid opgeneemde stikstof gemeet. Die beste nitraat: ammoniumverhouding was 3:1 by 100...

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Anorganiese stikstof in mieliegronde van die Oranje-Vrystaat en Transvaal met planttyd, 1984

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.C. du Preez --- Departement van Grondkunde, Republiek van Suid-Afrika R. du T. Burger --- Departement van Grondkunde, Republiek van Suid-Afrika

Ondersoek is ingestel na die hoeveelheid anorganiese stikstof wat met planttyd gedurende die 1984/85-seisoen in mieliegronde van die Oranje-Vrystaat en Transvaal teenwoordig was. By 82 lokaliteite, wat verspreid oor hierdie gebied voorkom, is grondmonsters ingesamel. Grondmonsters is op 300 mm...

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Laboratory measurements of ammonia volatilization from five nitrogen-containing fertilizers after surface application at different rates on a neutral to alkaline soil

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.C. du Preez --- Department of Soil Science, Republic of South Africa R. du T. Burger --- Department of Soil Science, Republic of South Africa

Volatilization losses of NH3 from five fertilizers, namely (NH4)2SO4, LAN, urea, MAP and DAP were determined. The fertilizers were applied to a Bainsvlei soil of which the pH was adjusted to 6,5; 7,6; 8,3 and 9,1. The application levels were...

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Effect of application methods on ammonia volatilization from soils in a controlled environment

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.C. du Preez --- Department of Soil Science, Republic of South Africa R. du T. Burger --- Department of Soil Science, Republic of South Africa

The objective of this investigation was to compare different application methods whereby ammonia losses from nitrogen fertilizers can be limited when applied to alkaline soils. Three application methods were simulated, namely broadcasting, ploughing under and band placement. Five nitrogen fertilizers,...

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The effect of tillage system and rate and time of nitrogen application on maize performance on a sandy Avalon soil

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: P.M. Lang --- , Republic of South Africa J.B. Mallett --- , Republic of South Africa

Four nitrogen fertilizer regimes were superimposed on a tillage trial on a sandy Avalon soil at Dundee in 1985 in order to investigate whether the rate and time of N fertilizer application influenced the poor early-season growth and reduced yields...

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The optimization of nitrogen and phosphorus application to cultivated Digitaria eriantha ssp. eriantha pasture

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: P.J. van Rooyen --- Directorate of Biometric and Datametric Services, Department of Agriculture and Water Affairs, Republic of South Africa C.S. Dannhauser --- Highveld Region, Department of Agriculture and Water Affairs, Republic of South Africa

A production function is derived and calibrated for Digitaria eriantha hay production in the Highveld region of the RSA. A procedure is described that optimizes this function for nitrogen and phosphorus application rates within economic and risk constraints at different...

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Invloed van bemesting op sonneblomme. I. Saadopbrengs

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: H.L. Loubser --- , Republiek van Suid-Afrika C.L. Grimbeek --- , Republiek van Suid-Afrika Beulah Bronkhorst --- , Republiek van Suid-Afrika

Bemestingsproewe is by drie lokaliteite oor vier seisoene uitgevoer deur 'n ongerepliseerde 43-gestrengelde faktoriaaluitleg te gebruik. Peile het gewissel van 0 tot 150 kg N ha−1, 0 tot 45 kg P ha−1, 0 tot 60 kg K ha−1 by twee...

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Die relatiewe belang van die vorm en konsentrasie van stikstof in die wortelsone op die ontwikkeling van Zea mays L.

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: F.G. Adriaanse --- , Republiek van Suid-Afrika J.J. Human --- Departement Agronomie en Hortologie, Republiek van Suid-Afrika

Die invloed van ses nitraat:ammoniumverhoudings by 200 mg N l1 in een proef en twee ander verhoudings by 50, 100 en 200 mg N l1 in 'n tweede proef is op droëmateriaalproduksie en stikstofinhoud ondersoek. Die algehele beste behandeling was...

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The influence of different P, NH⁺ ₄ and NO⁻ ₃ supply levels on the yield and P and Ca relationships in wheat

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.S. Claassens --- Department Soil Science and Plant Nutrition, Republic of South Africa W.J. Fölscher --- Department Soil Science and Plant Nutrition, Republic of South Africa

In a water culture experiment with wheat, the influence on growth and nutrient uptake of varying the P supply from 0,02 to 5 mmol H2PO4 − dm−3 and the NH4 +:NO3 − ratio from 0:15 to 12:3, with a Hoagland...

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Effect of time and rate of nitrogen application on the malting quality of barley

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: O.T. de Villiers --- Department of Agronomy and Pastures, Republic of South Africa P. C.J. Maree --- Department of Agronomy and Pastures, Republic of South Africa E.W. Laubscher --- Department of Agronomy and Pastures, Republic of South Africa

Field trials were conducted to determine the effect of time and rate of single and split applications of nitrogen on various malting parameters of barley. The effect of a single low nitrogen application of 50 kg Nha−1 at sowing was...

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Interaction of nitrogen fertilization and irrigation water salinity on growth of maize (Zea mays L.) in a two-way line-source sprinkler system

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: R.E. Steynberg --- Department of Plant Production, Republic of South Africa D. Magnusson --- , Israel Y. Ben-Asher --- , Israel M. Silberbush --- , Israel

Maize was planted in a line-source sprinkler experiment in the Negev Desert in Israel. A double line-source system was used with one line source at right angles to the other. It was possible to create a gradient of salt concentration...

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Drought sensitivity of maize (Zea mays L.) in relation to soil fertility and water stress during different growth stages

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: R.E. Steynberg --- Department of Plant Production, Republic of South Africa P.C. Nel --- Department of Plant Production, Republic of South Africa P.S. Hammes --- Department of Plant Production, Republic of South Africa

Maize was grown under controlled conditions in a pot experiment to determine how drought sensitivity would be affected by differential soil fertilities. Soil was obtained from a fertilization field trial where soil fertility differences developed over a period of 45...

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Die invloed van plantpopulasie op opbrengs en kwaliteit van katoen (Gossypium hirsutum L.) in die Vaalharts- en Sandvetbesproeiingsgebiede

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: L.P. de Bruyn --- Landboufakulteit, Republiek van Suid-Afrika J. de Kock --- Departement Landbou en Watervoorsiening, Kleingraansentrum, Republiek van Suid-Afrika J.J. Human --- Landboufakulteit, Republiek van Suid-Afrika

Die invloed van plantdigtheid op die opbrengs en kwaliteit van katoen is vir die Vaalharts- en Sandvetbesproeiingsgebiede ondersoek. Aangesien hoër plantpopulasies hoër eise aan water- en stikstofvoorsiening stel, is hierdie effek by verskillende peile van besproeiing en stikstofbemesting uitgetoets. Individuele...

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The effect of nitrogen and manganese on the aroma of flue-cured tobacco

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.S. Whitehead --- Department of Botany, Republic of South Africa C.J. Steenkamp --- , Republic of South Africa

Several volatile compounds are produced on curing fully aromatic tobacco leaves. In contrast, no volatiles are produced by ‘putty’ leaves. A clear correlation exists between the production of flavour compounds and the retention of structural integrity in the leaves after...

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Nitrogen mineralization, nitrification and nitrogen balance in laboratory incubation of soil from natural grassland in the central Orange Free State

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: G.H. Wiltshire --- Department of Soil Science, Republic of South Africa

Air-dried soil from three layers under grassveld was moistened by the addition of 12 levels of water and incubated for up to two years at five temperatures in screw-capped preserving jars with an air-filled head- space equivalent to seven times...

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Loss of nitrogen fertility and its restoration in some Orange Free State soils

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.A. Prinsloo --- Department of Soil Science, Republic of South Africa G.H. Wiltshire --- Department of Soil Science, Republic of South Africa C.C. du Preez --- Department of Soil Science, Republic of South Africa

The effects of present or past cultivation on nitrogen fertility in some central Orange Free State soils were investigated by the comparison of paired samples of cultivated or reverted soils with uncultivated soils situated as closely as possible to one...

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The effect of seeding rate, timing of nitrogen application and frequency of irrigation on wheat growth, yield and water use

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.A. Nel --- , Republic of South Africa F.J. Dijkhuis --- , Republic of South Africa

Wheat (Triticum aestivum cv. SST66) was planted in a 2 × 2 × 2 factorial field experiment. Factors investigated were seeding rate, timing of nitrogen application and frequency of irrigation. The two seeding rates were 85 and 170 kg ha−1...

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Invloed van bemesting op sonneblomme. II. N-, P- en K-verwydering deur die gewas

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: H.L. Loubser --- , Republiek van Suid-Afrika C.L. Grimbeek --- , Republiek van Suid-Afrika Beulah Bronkhorst --- , Republiek van Suid-Afrika

N-, P- en K-ontledings is gedoen op saad- en plantmonsters wat verkry is uit twee NPK bemestingsproewe en een N × P × kalkproef. Die resultate is gebruik om die N-, P- en K-verwydering deur verskillende plantdele te bereken. Daar...

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Nitraatontledings as hulpmiddel by stikstofbemestingaanbevelings in die westelike mielieproduserende gebiede van Suid-Afrika

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: P.P. van der Walt --- , Republiek van Suid-Afrika C.C. du Preez --- Departement van Grondkunde, Republiek van Suid-Afrika

Die ondersoek is onderneem om vas te stei of nitraatontledings gebruik kan word om die huidige stikstof- bemestingsriglyne in die westelike mielieproduserende gebiede te verfyn. Verskeie stikstofbemestingsproewe is by verskillende terreine in die gebiede uitgevoer. By elk van die 14...

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Concentration, accumulation and uptake rate of macro-nutrients by winter wheat under irrigation

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.C. du Preez --- Department of Soil Science, Republic of South Africa A. T.P. Bennie --- Department of Soil Science, Republic of South Africa

The objective of this study was to obtain information on the nutrient uptake patterns of winter wheat (Triticum aestivum L.) grown under normal irrigation farming conditions. Except for irrigation scheduling, 13 farmers were allowed to follow their normal farming practices...

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Urease-aktiwiteite in gronde van die sentrale besproeiingsgebiede in Suid-Afrika

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: F. P.J. Thormählen --- Departement van Grondkunde, Republiek van Suid-Afrika C.C. du Preez --- Departement van Grondkunde, Republiek van Suid-Afrika

Die oogmerk met die studie was om die omvang van urease-aktiwiteite in die besproeide gronde vas te stel en watter grondparameters dit beïnvloed. Die verloop van hidrolise is in agt gronde, afkomstig van die sentrale besproeiingsgebiede, gemonitor na toediening van...

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Utilization of initially-applied labelled ammonium nitrate by three successive crops

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A. D.P. Botha --- , Republic of South Africa D.C. Pretorius --- , Republic of South Africa J.C. Johnson --- , Republic of South Africa M.V. Kidson --- , Republic of South Africa

The aim of the study was to compare N uptake from initially-applied NH4 + and NO3- ions and to compile a balance sheet for applied fertilizer N. In a pot experiment, maize, sorghum and sunflower plants were grown in succession,...

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The influence of phosphorus on the tolerance of maize (Zea mays L.) to atrazine

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.F. Reinhardt --- Department of Plant Production, Republic of South Africa P.C. Nel --- Department of Plant Production, Republic of South Africa

Glasshouse and field studies were conducted to examine the effect of high phosphorus (P) application on the tolerance of the maize cultivar SSM2041 to atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-tria- zine]. Two glasshouse experiments were conducted. In one, seedlings were exposed to five P...

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Long-term effects of conservation practices on the nitrogen fertility of a soil cropped annually to wheat

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: G.H. Wiltshire --- Department of Soil Science, Republic of South Africa C.C. du Preez --- Department of Soil Science, Republic of South Africa

Sustainable farming in the semi-arid interior of South Africa requires the adoption of conservation practices to maintain and, if possible, increase soil fertility. The effects of some such practices on the nitrogen fertility of a hydromorphic sandy clay loam soil...

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Measurements of mineralization, nitrification and denitrification in laboratory incubations of soil from a semi-arid natural grassland

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: G.H. Wiltshire --- Department of Soil Science, Republic of South Africa C.C. du preez --- Department of Soil Science, Republic of South Africa

Experiments were done to compare three incubation methods after it was found that prolonged incubation of soil in sealed preserving jars resulted in the exhaustion of head- space oxygen and anaerobiosis in the soil. Nitrate added to soil from the...

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Verwantskap tussen organiese materiaalinhoud van sekere onversteurde bogronde, grondeienskappe en klimaatsdata in Suid-Afrika

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.E. du Toit --- , Republiek van Suid-Afrika C.C. du Preez --- Departement van Grondkunde, Republiek van Suid-Afrika

Die doel met die ondersoek was om vas te stel of die organiese materiaalinhoud van onversteurde ortiese A-horisonte, wat deur rooi apedale, geelbruin apedale en sagte plintiese B-horisonte onderlê word, vanaf beskikbare of maklik meetbare grondeienskappe en klimaatsdata bereken kan...

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Effects of sample drying temperature on indices of available nitrogen in soils

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: G.H. Wiltshire --- Department of Soil Science, Republic of South Africa C.C. du Preez --- Department of Soil Science, Republic of South Africa

During a field trial investigation into the long-term effects of conservation practices on the nitrogen fertility of a soil cropped annually to wheat, it was observed that sample preparation had an effect on some indices of available nitrogen. The trial...

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Nitrogen mineralization in selected soils from the maize producing areas of South Africa

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: GailA. van der Mey --- , Republic of South Africa H.M. Combrink --- , Republic of South Africa C.C. du Preez --- Department of Soil Science, Republic of South Africa

The aim of this study was to relate nitrogen mineralization from soil to selected soil properties more easily obtained in the laboratory. Net nitrogen mineralization was determined to varying depths (0–200, 200–400 and 400–600 mm) in 21 soil profiles from...

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Effek van bewerking op die organiese materiaalinhoud van geselekteerde droëlandgronde in Suid-Afrika

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.E. du Toit --- , Republiek van Suid-Afrika C.C. du Preez --- Departement van Grondkunde, Republiek van Suid-Afrika M. Hensley --- , Republiek van Suid-Afrika A. T.P. Bennie --- Departement van Grondkunde, Republiek van Suid-Afrika

Die doel van die ondersoek was om (1) die effek van bewerking op die organiese materiaalinhoud van gronde te kwantifiseer indien onversteurde gronde as verwysing dien; (2) die verband tussen bewerkingstyd en die afname in organiese materiaal te kry en...

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Reaksie van twee lentekoringkultivars op stikstof- en swaelbemesting in die Swartland. I. Vegetatiewe groei, opname en konsentrasie van stikstof en swael in die vegetatiewe plant

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J.P. du Plessis --- , Republiek van Suid-Afrika G.A. Agenbag --- Departement Akkerbou en Weidlng, Republiek van Suid-Afrika

Die belangrikheid van die korrekte N: S verhouding het die vraag laat ontstaan of 'n wanbelans tussen N en S nie gedeeltelik 'n bydrae tot die swak benuttingsdoeltreffendheid van N by hoë N-bemestings in die Swartland kan lewer nie. 'n...

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Reaksie van twee lengtekoringkultivars op stikstof- en swaelbemesting in die Swartland. II. Opbrengs en bakkwaliteit

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J.P. du Plessis --- , Republiek van Suid-Afrika G.A. Agenbag --- Departement Akkerbou en Weiding, Republiek van Suid-Afrika

In die Swartlandkoringproduksiegebied is daar oor die afgelope tien jaar 'n daling in die gemiddelde prote'ieninhoud en bakkwaliteit van koring ondervind, selfs ten spyte van verhoogde stikstofbemesting. Die belangrikheid van die korrekte N: S verhouding het die vraag laat ontstaan...

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Effect of cultivation on the nitrogen fertility of selected dryland soils in South Africa

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.E. du Toit --- , Republic of South Africa C.C. du Preez --- Department of Soil Science, Republic of South Africa

This study is part of an investigation into the effect of cultivation on the organic matter content of topsoils (0 - 200 mm) from commercial farms practising dryland agriculture in the summer rainfall area of South Africa (24°-30°S; 24°-30°E). The...

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Effek van residuele plus toegediende stikstof op graanopbrengs van mielies in die Hoëveldstreek

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.A. Bloem --- , Republiek van Suid-Afrika R.O. Barnard --- Departement van Grondkunde en Plantproduksle, Republiek van Suid-Afrika

Die behoefte in Suid-Afrika aan stikstofbemestingsriglyne wat op 'n meer fundamentele basis berus, het aanleiding gegee dat drie veldproewe in die 1992/93 groeiseisoen begin is. Residuele NO3-N is na oes (Julie 1993) en voor plant (November 1993) op dieptes van...

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The yield response of annual ryegrass (Lolium multiflorum) to varying nitrogen fertilizer application strategies

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: R.J. Eckard --- , Republic of South Africa P.E. Bartholomew --- , Republic of South Africa N.M. Tainton --- Department of Grassland Science, Republic of South Africa

Annual ryegrass (Lolium multiflorum LAM. cv. Midmar) pastures were established on three sites, representing the Avalon, Katspruit and Inanda soil forms, with cut-plot experimentation over a period of four years (1987 - 1990). Nitrogen fertilizer was top-dressed at 0, 200,...

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Effek van bewerkingstyd op die afname van totale swawel in geselekteerde Suid-Afrikaanse gronde

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.C. du Toit --- , Republiek van Suid-Afrika C.C. du Preez --- Departement Grondkunde, Republiek van Suid-Afrika

'n Afname van 4–70% in die totale S van bogronde as gevolg van bewerking het die vraag laat ontstaan hoe hierdie verlies verband hou met die periode van bewerking en of so 'n verwantskap tussen ekotope verskil. Bewerkte en nabygeleë...

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Effect of yellow berry on yield and protein composition of spring wheat (Triticum aestivum L.)

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: N.C. Raath --- Department of Agriculture, Republic of South Africa G.A. Agenbag --- Department of Agronomy and Pastures, Republic of South Africa O.T. de Villiers --- Department of Botany, Republic of South Africa

Yellow berry is a physiological condition in wheat which is associated with nitrogen stress. Results from an experiment where some treatments resulted in unusually large percentages of yellow berry kernels indicated a negative relationship between the incidence of yellow berry...

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Evaluation of an undisturbed-soil incubation method as an index of soil nitrogen availability in a limed and non-limed soil

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: P.J. Raath --- , Republic of South Africa D. Saayman --- Department of Soil and Agricultural Water Science, Republic of South Africa

Nitrogen mineralization potentials were determined using an undisturbed-soil incubation procedure. The purpose of this study was to evaluate the above-mentioned method as an index of soil nitrogen availability. Undisturbed soil samples (0–150 and 150–300 mm) of a limed (pH 7.3)...

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Kwantifisering van die opname van atmosferiese en grond-N deur sojabone [Glycine max (L.) Merrill] uit ¹⁵ N-verrykte grond

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A. D. P. Botha --- , Republiek of Suid-Afrika D.C. Pretorius --- , Republiek of Suid-Afrika J.F. Bienkowski --- , Republiek of Suid-Afrika R. L.J. Coetzer --- , Republiek of Suid-Afrika

Die doel met hierdie ondersoek was om die atmosferiese en grondstikstofopname deur die groeiseisoen van sojabone vas te stei, te bepaal in watter plantdele die N afkomstig van die twee bronne versamel, of dit later na die saad getranslokeer word...

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Fosfor in geselekteerde onversteurde en bewerkte Suid-Afrikaanse gronde 1. Totale, anorganiese en organiese fosfor

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.J. van Zyl --- Departement Grondkunde, Republiek van Suid-Afrika C.C. du Preez --- Departement Grondkunde, Republiek van Suid-Afrika

Min is bekend oor die effek van boerderypraktyke soos bewerking, bemesting en bekalking op die fosforfraksies in gronde van die somerreënvalgebied (25°-30°S; 24°–30°O) in Suid-Afrika. Die doelstellings van die studie was om die effek van gewasverbouing op die totale (Pt),...

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Changes in the organic matter and nutrient contents of some South African irrigated soils

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.C. du Preez --- Department of Soil Science, Republic of South Africa G.H. Wiltshire --- Department of Soil Science, Republic of South Africa

Cultivation caused, without exception, a decline in the organic matter content of dryland soils in the central regions of South Africa. The question arose as to how cultivation affects the organic matter content of irrigated soils from these regions. The...

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Response of maize to ammonium nitrate, urea and cogranulated urea-urea phosphate

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: O.A. Yerokun --- Department of Soil Science, Zambia

Urea fertilizers may lose N by ammonia volatilization when applied in the field. In order to reduce this loss, modified urea compounds are being used. Not all of them reduce ammonia loss and improve crop yields. A field study was...

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Ammonia volatilization from ammonium nitrate, urea and urea phosphate fertilizers applied to alkaline soils

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: O.A. Yerokun --- Department of Soil Science, Zambia

The volatilization of ammonia following applications of urea fertilizers to soils may release significant amounts of N into the atmosphere and reduce the plant available N. This study compared ammonia loss from urea phosphate (170 g N kg−1, 190 g...

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Die invloed van kultivar, stikstofbemesting en tophoogte op die kwaliteit van oonddroogtabak I. Fisiese kwaliteit en opbrengs

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: G.J. Malan --- Departement Plantproduksie en Grondkunde, Republiek van Suid Afrika P.S. Hammes --- Departement Plantproduksie en Grondkunde, Republiek van Suid Afrika M.C. Dippenaar --- Navorsingsinstituut vir Tabak en Katoen, Republiek van Suid Afrika

Die toenemende vraag na goeie kwaliteit oonddroogtabak het aanleiding gegee tot navorsing om te bepaal watter rol stikstofbemesting, tophoogte en kultivars speel. Vyf oonddroogtabakkultivars (TL 33, OD86, A4, OD224 en OD212) is in 'n veldproef onderwerp aan drie stikstofbemestingspeile (70,...

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Detecting nitrogen deficiency on irrigated cash crops using remote sensing methods

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: P.S. Fouche --- Department of Soil Science, Republic of South Africa

Early detection of nitrogen deficiency on annual agricultural crops can assist the management of N-fertilization to improve crop yields. Low altitude aerial photography is an inexpensive means to assess crop canopy radiation in the near infrared range. In this study,...

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Spatial variability of nitrate nitrogen in soil during the growing season of maize, cowpea and soybean

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.A. Bloem --- Department of Agriculture, North West Province, Republic of South Africa R.O. Barnard --- Department of Plant Production and Soil Science, Republic of South Africa

The nitrogen advantage of legumes in crop rotation systems is well known, but the nitrogen advantage from legumes to associated crops in an intercropping system is unclear. The objective of this study was to determine whether plant-available nitrogen is released...

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The yield and processing quality of sunflower seed as affected by the amount and timing of nitrogen fertiliser

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.A. Nel --- , Republic of South Africa H.L. Loubser --- , Republic of South Africa P.S. Hammes --- Department of Plant Production and Soil Science, Republic of South Africa

The response of sunflower (Helianthus annuus L.) seed yield and seed processing quality to the amount and timing of nitrogen were studied in a field trial. Nitrogen application rates were 20, 70 and 120 kg ha−1 with limestone ammonium nitrate...

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Rate and timing of nitrogen fertilizer applications on wheat grown under dryland and supplementary irrigation

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J.A. Adjetey --- , Australia P. G.E. Searle --- , Australia L.C. Campbell --- , Australia

Field experiments were carried out at the University of Sydney Farm, to examine nitrogen fertilizer application strategies for increasing N uptake and productivity of wheat (Triticum aestivum L.) grown on a red-brown earth (Natrixeralf) in Australia, under dryland and supplementary...

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Effect of annual legumes on soil nitrogen and on the subsequent yield of maize and grain sorghum

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.A. Bloem --- Department of Agriculture, Conservation and Environment, Republic of South Africa R.O. Barnard --- Department of Plant Production and Soil Science, Republic of South Africa

The objective of this study was to quantify the nitrogen and yield advantage of cowpea, soybean and groundnuts to succeeding maize and grain sorghum crops. Treatments at six localities consisted of a crop rotation with annual legumes and maize or...

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Evaluation of petiole nitrate measurement as an aid for N fertilization of potatoes (Solanum tuberosum L.) on sandy soils

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: P.P. Brink --- Department of Agronomy and Pastures, N. J.J. Combrink --- Department of Agronomy and Pastures, F.H. Knight --- Department of Agriculture, Western Cape,

Potatoes are produced in the Sandveld of the Western Cape on soils with extremely low clay and organic material contents. A low nitrogen mineralisation potential and high leaching hazard complicate the management of the nitrogen supply to the plant. This...

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Effect of nitrogen supply on the production and distribution of dry matter in sugarcane

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. C.S. Allison --- , South Africa N.W. Pammenter --- , South Africa

Sugarcane productivity is probably limited by characteristically slow early growth and, later, by progressively decreasing leaf nitrogen (N) concentration. Increasing the N supply might increase productivity by influencing these attributes. In a pot experiment on two cultivars N was supplied...

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Effect of planting density on dry matter partitioning in young ‘Laetitia’ / ‘Marianna’ plum trees grown in lysimeter tanks

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Wooldridge --- , Republic of South Africa C. Schutte --- , Republic of South Africa

The effects of increasing planting density on young lysimeter tank-grown plum trees were investigated. Seasonal increases in stem circumference, and average shoot lengths, decreased significantly (P = 0.05) as the number of trees per 1.4 × 3.0 m tank increased...

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Effect of timing and method of nitrogen application on rind colour, fruit size, internal fruit quality and yield of ‘Mihowase Satsuma’ mandarin (Citrus unshiu Marc.)

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: F.N. Mudau --- Department of Horticultural Science, Republic of South Africa S. Tuwana --- Department of Horticultural Science, Republic of South Africa K.I. Theron --- Department of Horticultural Science, Republic of South Africa E. Rabe --- Department of Horticultural Science, Republic of South Africa

Early rind colour development is a major problem in the production of early-maturing ‘Mihowase Satsuma’ mandarin (Citrus unshiu Marc.) in the Western Cape, South Africa. The effect of different combinations of soil- applied limestone ammonium nitrate and foliar-applied low-biuret urea...

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SOIL carbon and nitrogen in five contrasting biomes of South Africa exposed to different land uses

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.J. Mills --- Department of Soil Science, South Africa M.V. Fey --- Department of Soil Science, South Africa

Stocks of soil C to a depth of 50 cm in untransformed, indigenous veld ranged from 21 t ha-1 in karoo to 168 t ha-1 in thicket and stocks of N ranged from 3.41 ha-1 in karoo to 12.8 t...

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Effect of soil tillage, crop rotation and nitrogen application rates on plant-N content of spring wheat (Triticum aestivum L.) in the Swartland wheat-producing area of the Republic of South Africa

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: S.H. Maali --- Department of Agronomy, Republic of South Africa G.A. Agenbag --- Department of Agronomy, Republic of South Africa

Studies on nitrogen content in spring wheat were conducted during the 2000 and 2001 growing seasons as part of a long-term tillage and crop rotation trial. Four tillage methods were used, namely conventional tillage (CT), tine tillage (TT), minimum tillage...

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Effect of adjuvants on apple fruit and leaf calcium and nitrogen concentrations at three fruit growth stages

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M. North --- , J. Wooldridge --- ,

In a field trial, 0.006% v/v Agral-90® and four alternative adjuvants were evaluated to determine their effects on calcium (Ca) and nitrogen (N) uptake by leaves and fruit of ‘Golden Delicious’ apple from 0.45% m/v calcium nitrate sprays. No bitter...

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Growth and yield compensation in sorghum (Sorghum bicolor L. Moench) as a function of planting density and nitrogen fertilizer in semi-arid areas of northeastern Ethiopia

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Wondimu Bayu --- Department of Plant Production and Soil Science, South Africa N. F.G. Rethman --- Department of Plant Production and Soil Science, South Africa P.S. Hammes --- Department of Plant Production and Soil Science, South Africa

An experiment was conducted at two locations in northeastern (NE) Ethiopia to determine the effect of population density on the growth, yield and nitrogen use efficiency of sorghum (Sorghum bicolor L. Moench) under two levels of nitrogen fertilizer application. Eight...

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Effect of soil tillage, crop rotation and nitrogen application rates on bread-baking quality of spring wheat (Triticum aestivum L.) in the Swartland wheat producing area of South Africa

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: S.H. Maali --- Department of Agronomy, Republic of South Africa G.A. Agenbag --- Department of Agronomy, Republic of South Africa

Spring wheat (Triticum aestivum L.) is produced in the wheat producing areas of the Western Cape Province, Republic of South Africa, primarily for bread-baking purposes. Milling and baking characteristics are therefore of utmost importance. In a long-term tillage and crop...

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Effects of early season and autumn nitrogen applications on young ‘Keisie’ canning peach trees on a sandy, infertile soil

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Wooldridge --- , South Africa

The effects of autumn (A) and early season (S) nitrogen (N) applications were investigated in a young ‘Keisie’ canning peach orchard on an infertile sandy soil in the Western Cape Province, South Africa. Over the first four consistent bearing seasons,...

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Effects of potassium and early-season nitrogen applications on young ‘Keisie’ canning peach trees on a sandy, infertile soil

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Wooldridge --- , South Africa

The effects of different rates of potassium (K) and early season nitrogen (SN) were investigated in a ‘Keisie’ canning peach orchard on a sandy, infertile soil, at 1111 trees ha−1, in the Western Cape Province, South Africa. Over the first...

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Relationship between inorganic soil nitrogen and maize grain yield with controlled traffic practices

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C. J.J. Schmidt --- , South Africa S.A. Smalberger --- , South Africa S.A. Smalberger --- , South Africa F.G. Adriaanse --- , South Africa C.C. du Preez --- , South Africa

Traditional N fertilizer guidelines were based on relationships between N application rates and yield response. These relationships varied greatly according to residual inorganic N content in the soil. The objective of this study was to establish inorganic N threshold values...

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The delta yield procedure for nitrogen fertilisation of maize in South Africa

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.A. Nel --- , Republic of South Africa A.A. Bloem --- Department of Agriculture, Republic of South Africa

The nitrogen fertilisation requirement for maize in South Africa is generaly estimated through the optimum yield-nitrogen rate procedure. The efficacy of this procedure is questionable. Delta yield, the difference between the maize grain yield at the economic optimum and that...

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The effect of fertiliser N rates on growth of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) grown at high soil water levels under controlled conditions

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Labuschagne --- , South Africa G.A. Agenbag --- , South Africa

The response of perennial ryegrass and white clover to fertiliser N rates of 0, 30, 60, 120 and 180 kg N ha−1 when grown at soil water potentials of-10, −20, −25 and −35 kPa were investigated. Increasing fertiliser N levels...

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The effects of strategic nitrogen fertiliser application during the cool season on perennial ryegrass-white clover pastures in the Western Cape Province 1. Soil nitrogen dynamics

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Labuschagne --- , South Africa M.B. Hardy --- Department of Agriculture Western Cape, South Africa G.A. Agenbag --- , South Africa

The dynamics of soil inorganic-N in reaction to a single, strategic application of fertiliser N were studied during the period 2000 to 2002 in an Oakleaf soil with a clay content increasing from 10 to 30.8% with depth. Soil inorganic-N...

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The effects of strategic nitrogen fertiliser application during the cool season on perennial ryegrass-white clover pastures in the Western Cape Province 2. Dry matter production

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Labuschagne --- , South Africa M.B. Hardy --- Department of Agriculture Western Cape, South Africa G.A. Agenbag --- , South Africa

The response of an irrigated perennial ryegrass-white clover pasture to fertiliser nitrogen application rates of 0, 50, 100 and 150 kg N ha−1 applied in either autumn, early winter, late winter, early spring or late spring was investigated over a...

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The effects of strategic nitrogen fertiliser application during the cool season on perennial ryegrass-white clover pastures in the Western Cape Province 3. Clover content

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Labuschagne --- , South Africa M.B. Hardy --- Department of Agriculture Western Cape, South Africa G.A. Agenbag --- , South Africa

The influence of a single application of fertiliser N (0, 50, 100 and 150 kg N ha−1) applied in either autumn, early winter, late winter, early spring or late spring on the grass-clover balance in a perennial ryegrass-white clover pasture...

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Fate of nitrogen applied to maize on conventional and minimum tilled Nitisols in Western Ethiopia

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: D. Tolessa --- Department of Soil, Crop and Climate Sciences, South Africa C.C. Du Preez --- Department of Soil, Crop and Climate Sciences, South Africa G.M. Ceronio --- Department of Soil, Crop and Climate Sciences, South Africa

Maize production in western Ethiopia is practiced mainly on Nitisols inherently low in N. Neither conventional nor minimum tilled maize reaches its full yield potential without fertilization. A large amount of applied N usually escapes from the soil-crop system and...

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Influence of long-term wheat residue management on organic matter in an Avalon soil

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: E. Kotzé --- Department of Soil, Crop and Climate Sciences, Republic of South Africa C.C. du Preez --- Department of Soil, Crop and Climate Sciences, Republic of South Africa

This study was initiated to determine the influence of different wheat residue management practices, that were sustained for about 20 years, on the organic matter content of an Avalon soil in a long-term trial near Bethlehem in the Eastern Free...

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The lower and upper threshold values, biological optimum and mineralization of nitrogen in the main maize producing soils of South Africa

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J.J. Van Biljon --- , 2021 Republic of South Africa D.S. Fouche --- , 2021 Republic of South Africa A.D.P. Botha --- , Republic of South Africa

There is still no consensus in South Africa on the parameters used to advise maize farmers on the quantity of N needed for optimum yields. In order to determine the lower and upper threshold values for nitrogen (N), the biological...

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The effect of low soil temperature and fertiliser N rate on perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) grown under controlled conditions

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Labuschagne --- , South Africa G.A. Agenbag --- , South Africa

The response of perennial ryegrass and white clover to soil temperatures of 6, 12 and 18°C, and to nitrogen applications equivalent to 0, 50, 100 and 150 kg N ha−1, were investigated under controlled conditions. Ryegrass primary dry matter production...

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Nitrogen fixation and biomass productivity of indigenous legumes for fertility restoration of abandoned soils in smallholder farming systems

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: H. Nezomba --- , Zimbabwe T. P Tauro --- , Zimbabwe F. Mtambanengwe --- , Zimbabwe P. Mapfumo --- , Zimbabwe

Most legume-based soil fertility technologies often fail to make the desired impact on nutrient-depleted soils partly due to low N2-fixation rates and poor biomass productivity. A study was conducted in the 2004/05 and 2005/06 rainfall seasons to evaluate biomass productivity...

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Effects of liming on microbial activity and N mineralization in broiler manure-amended soils from Bizana, Eastern Cape, South Africa

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: G.G. Jezile --- Department of Soil and Crop Sciences, USA D.G. Westfall --- Department of Soil and Crop Sciences, USA G. Peterson --- Department of Soil and Crop Sciences, USA D.R. Child --- Department of Rangeland Ecosystem Sciences, USA D.P. Turner --- , RSA W. Van Averbeke --- , RSA

A laboratory incubation study was conducted to determine the effects of liming on microbial activity and N mineralization in two Bizana soils amended with broiler manure. The experimental layout was a 4 x 3 complete factorial experiment with three replicates,...

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Grain yield, nitrogen uptake and use efficiency components of South African irrigation wheat cultivars under different nitrogen management strategies

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: W.M. Otto --- , South Africa C.C. du Preez --- Department of Soil, South Africa

The effect of different N management strategies on the grain yield, N uptake and use efficiency components of five commercial wheat cultivars were investigated for two consecutive years at Riet River and Loskop irrigation schemes. The cultivars ranged ingrowth period...

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Preliminary evaluation of the effectiveness of Rhizobium leguminosarum bv. viceae strains in nodulating hairy vetch (Vicia villosa) in the sandy soils of Zimbabwe

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Akinson Tumbure --- Soil Productivity Research Laboratory, Department of Research and Specialist Services, Zimbabwe Menas Wuta --- Department of Soil Science and Agricultural Engineering, Zimbabwe Farai Mapanda --- Department of Soil Science and Agricultural Engineering, Zimbabwe

Hairy vetch (Vicia villosa Roth) is an introduced temperate forage legume in Zimbabwe that has no locally available commercial inoculant. In this study, Rhizobium leguminosarum bv. viceae strains MAR 1504, MAR 833 and MAR 346 available in Zimbabwe's strain bank...

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A vetch winter cover crop can improve response to nitrogen fertiliser and profitability of no-till maize

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Ernest Dube --- Department of Agronomy, Faculty of Science and Agriculture, South Africa Cornelius Chiduza --- Department of Agronomy, Faculty of Science and Agriculture, South Africa Pardon Muchaonyerwa --- School of Agricultural, Earth and Environmental Sciences, South Africa

A high nitrogen (N) fertiliser requirement can be a deterrent to the adoption of conservation agriculture (CA). A field trial was carried out to test whether a high biomass-yielding vetch (Vicia dasycarpa L.) winter cover crop can be used to...

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NITROGEN TRANFORMATIONS AND THE NITROGEN BUDGET OF A HYPERTROPHIC IMPOUNDMENT (HARTBEESPOORT DAM, SOUTH AFRICA)

Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: P.J. Ashton --- , South Africa

The major components of the nitrogen balance of hypertrophic Hartbeespoort Dam were studied at weekly intervals from October 1980 to September 1984. The Crocodile River contributed over 80Z of the hydraulic load and over 97X of the annual total nitrogen...

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NUTRIENTS IN AQUATIC ECOSYSTEMS: AN INTRODUCTION TO SIMILARITIES BETWEEN FRESHWATER AND MARINE ECOSYSTEMS

Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: P Chapman --- , South Africa JA Thornton --- , South Africa

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NUTRIENTS IN AFRICAN LAKE ECOSYSTEMS: DO WE KNOW ALL?

Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: J.A. Thornton --- , South Africa

It is nearly sixty years since the first studies were undertaken on the nutrient chemistry of African lakes. There have been numerous studies on the chemical composition of African waters in the intervening years. Yet as recently as five years...

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NUTRIENT CYCLING IN MARINE ECOSYSTEMS

Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: P. Chapman --- , South Africa

The overall cycles of nitrogen, phosphorus and silicon in the sea are described and compared. Data on the fluxes and rates of change between various pools of each nutrient are given, where available, and gaps in knowledge are pointed out...

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DECOMPOSITION IN PELAGIC MARINE ECOSYSTEMS

Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: M.I. Lucas --- Zoology Department, South Africa

During the decomposition of plant detritus, complex microbial successions develop which are dominated in the early stages by a number of distinct bacterial morphotypes. The microheterotrophic community rapidly becomes heterogenous and may include cyanobacteria, fungi, yeasts and bactivorous protozoans.

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APPLICATION OF LAVSOE, AN EUTROPHICATION MODEL, TO BLOEMHOF DAM

Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: J.N. Rossouw --- ,

In 1985 the Department of Water Affairs introduced an effluent phosphate standard of 1 mg l−1 (as P) in seven potentially sensitive catchments. Although this is an uniform standard, permits can be granted for effluents to exceed the standard in...

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Effect of plant height at cutting, source and level of fertiliser on yield and nutritional quality of Napier grass (Pennisetum purpureum (L.) Schumach.)

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: T Zewdu RMT Baars A Yami

Napier grass (Pennisetum purpureum (L.) Schumach.) was studied using a 5 x 3 factorial experiment arranged in a randomised complete block design with three replications. The treatments were five fertiliser applications (0kg ha-1 N, 46kg ha-1 N and 92kg ha-1...

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The influence of nitrogen and defoliation on the nitrogen content of Lolium multiflorum cv. Midmar

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: J F Theron W L J van Rensburg H A Snyman

The response of the nitrogen content in ryegrass (Lolium multiflorum cv. Midmar) to a variation in applied nitrogen (0kg N ha-1, 150kg N ha-1, 300kg N ha-1 and 450kg N ha-1) and defoliation intervals (every 2, 4, 6 and 8...

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An evaluation of diet quality in two desert ungulates exposed to hyper-arid conditions

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: SR Henley D Ward

Desert-dwelling ungulates are frequently exposed to plant communities of poor nutritional quality and low abundance. We assessed the diet quality of a large-bodied non-ruminant, the Asiatic wild ass (Equus hemionus) and that of a small-bodied ruminant, the dorcas gazelle (Gazella...

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Dry matter and nonstructural carbohydrate content as quality parameters in a Lolium multiflorum breeding programme

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: J.P. Marais --- , Republic of South Africa M. de Figueiredo --- , Republic of South Africa D.C.W. Goodenough --- Agricultural Research Council, Republic of South Africa

A Lolium multiflorum cv. Midmar pasture and ninety individual plants (both Italian and Westerwolds types), from 15 different Lolium multiflorum cultivars in a spaced‐plant trial, were assessed for total nonstructural carbohydrate (TNC) content, TNC yield, dry matter (DM) content, DM...

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Factors affecting the voluntary feed intake of sheep grazing Pennisetum clandestinum (kikuyu) pastures: Observations from forage analysis

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: J.P. Henaar --- Agricultural Research Council, Republic of South Africa N.M. Tainton --- Department of Grassland Science, Republic of South Africa J.B.J. van Ryssen --- Department of Animal & Poultry Science, Republic of South Africa

Sheep were used in two investigations to study factors which could limit voluntary intake of Pennisetum clandestinum (kikuyu) pasture. Possible reasons for the low intakes were found in the high soluble nitrogen and nitrate content of the pasture, its high...

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Factors affecting the voluntary feed intakes of sheep grazing Pennisetum clandestinum (kikuyu) pastures: Observations in the animal

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: J.P. Pienaar --- Agricultural Research Council, Republic of South Africa N.M. Tainton --- Department of Grassland Science, Republic of South Africa J.B.J. van Ryssen --- Department of Animal and Poultry Science, Republic of South Africa J.P. Swiegers --- , Republic of South Africa

Two experiments designed to establish possible reasons for the often‐observed low voluntary feed intake of animals grazing kikuyu pastures were conducted at two widely differing locations. Low digestibility and low rate of digestion limited feed intake only when sheep were...

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Towards identifying the fate of ¹⁵N applied in spring as ammonium nitrate fertiliser to a kikuyu pasture

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: G.D. Hefer --- Department of Grassland Science, Republic of South Africa D.C. Pretorius --- Department of Grassland Science, Republic of South Africa N.M. Tainton --- Department of Grassland Science, Republic of South Africa

Nitrogen was applied as ammonium nitrate in solution to kikuyu pasture at 225 kg N ha‐1, split into three equal dressings and applied in October, December and February. The first, at 75 kg N ha‐1 was labelled in the ammonium...

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Effect of grazing frequency and intensity on Lolium perenne L. pastures under subtropical conditions: Herbage quality

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: F.R. Mckenzie --- Department of Grassland Science, Republic of South Africa N.M. Tainton --- Department of Grassland Science, Republic of South Africa

The cellulase dry matter disappearance (CDMD) and herbage nitrogen (N) of Lolium perenne (perennial ryegrass) were evaluated for pastures grown under subtropical conditions for two years, under five combinations of grazing frequency and intensity, each applied in a rotational grazing...

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Effect of management factors on tiller dynamics in tall fescue: Tiller initiation

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: R.L. Phillips --- KwaZulu‐Natal Department of Agriculture, Republic of South Africa N.M. Tainton --- Department of Grassland Science, Republic of South Africa J.D.H. Reusch --- , Republic of South Africa D.E.A. Cumming --- Department of Grassland Science, Republic of South Africa

The effect of plant density (row spacing / seeding rate), nitrogen (N) fertilization, cultivar choice and close‐down date on tiller initiation in tall fescue (Festuca arundinacea Schreb.), managed for seed production, was examined over two years. In the first season,...

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Effect of management factors on tiller dynamics in tall fescue: Tiller mortality

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: R.L. Phillips --- KwaZulu‐Natal Department of Agriculture, Republic of South Africa N.M. Tainton --- Department of Grassland Science, Republic of South Africa J.D.H. Reusch --- , Republic of South Africa D.E.A. Dimming --- Department of Grassland Science, Republic of South Africa

The effect of plant density (row spacing / seeding rate), cultivar choice, nitrogen (N) fertilization and close‐down date on tiller mortality in a dual purpose (forage and seed) tall fescue (Festuca arundinacea Schreb.) sward was examined over a two‐year period...

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Effect of management factors on tiller dynamics in tall fescue: Numbers of tillers reaching reproductive maturity

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: R.L. Phillips --- KwaZulu‐Natal Department of Agriculture, Republic of South Africa N.M. Tainton --- Department of Grassland Science, Republic of South Africa J.D.H. Reusch --- , Republic of South Africa D.E.A. Cumming --- Department of Grassland Science, Republic of South Africa

The effect of plant density (row spacing / seeding rate), cultivar choice, nitrogen (N) fertilization and close‐down date on the number of reproductive tillers surviving to maturity in tall fescue (Festuca arundinacea Schreb.) was examined over a two‐year period. A...

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Responses of productive and unproductive kikuyu pastures to top‐dressed nitrogen and phosphorus fertiliser

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: N. Miles --- KwaZulu‐Natal Department of Agriculture, Republic of South Africa

In South Africa there is widespread reliance on kikuyu grass as a source of summer forage for intensive dairy, beef and sheep enterprises. There is, however, a dearth of reliable information on the fertility requirements of kikuyu pastures. Responses of...

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The influence of nitrogen and defoliation on production and water‐use efficiency of Lolium multiflorum cv. Midmar

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: J.F. Theron --- Department of Agriculture, FSR‐E Unit, Republic of South Africa W.L.J. van Rensburg --- Department of Grassland Science, Republic of South Africa

The objective of this study was to investigate the influence of different nitrogen fertiliser application levels in combination with different defoliation intervals on the dry matter (DM) production and water‐use efficiency of ryegrass (Lolium multiflorum,) cv. Midmar. In a field...

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Spring and autumn nitrogen fertiliser effects, with and without phosphorus, potassium and sulphur, on dairy pastures: Yield and botanical composition

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: F.R. McKenzie --- Department of Natural Resources and Environment, Australia J.L. Jacobs --- Department of Natural Resources and Environment, Australia M. Ryan --- Department of Natural Resources and Environment, Australia G. Kearney --- Department of Natural Resources and Environment, Australia

Experiments were conducted at three sites to study effects of different nitrogen (N) fertilisers (e.g. urea, ammonium nitrate, di‐ammonium phosphate and ammonium sulphate), applied at 45 kg N ha−1, with and without phosphorus (P), potassium (K) and sulphur (S), on...

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In vitro organic matter disappearance of tanniferous browse using rumen liquid from goats ingesting grass versus browse

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Caroline C Wambui --- Egerton University, Kenya James P Muir --- Texas A&M AgriLife Research, USA John Githiori --- International Livestock Research Institute, Kenya Barry D Lambert --- Texas A&M AgriLife Research, USA

In vitro organic matter disappearance (IVOMD) of African browse species often indicates artificially low nutritive value due to the presence of condensed tannins (CT). Diet of the rumen liquor donor may change this if it contains CT. Leaves from 11...

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Towards the assessment of the trophic status of South African impoundments for management purposes: Bon Accord Dam

Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: CE van Ginkel BC Hohls E Vermaak

The 1 mg/l phosphate effluent standard legislated in South Africa in 1980 in seven sensitive catchments, and ad hoc eutrophication-related requests, necessitated the monitoring of 53 impoundments throughout the country. Variables that were monitored, and are still being monitored in...

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Biomagnification of mercury in fish from Thruston Bay, Napoleon Gulf, Lake Victoria (East Africa)

Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: LindaM Campbell JS Balirwa DG Dixon RE Hecky

Total mercury concentrations (THg) were measured in fish from Thruston Bay, Napoleon Gulf in northern Lake Victoria between 1998 and 2000. Total Hg concentrations in Lates niloticus (Nile perch) and Oreochromis niloticus (Nile tilapia) ranged from 10.6 to 77.5ng g–1...

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Biodiversity and extracellular enzymatic activity of heterotrophic bacterial communities in Bardawil Lagoon, Egypt

Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: M Bahgat --- Department of Botany, Faculty of Sciences, Egypt A Dewedar --- Department of Botany, Faculty of Sciences, Egypt HM Shafik --- Department of Botany, Faculty of Sciences, Egypt EE Shabana --- Department of Botany, Faculty of Sciences, Egypt

The biodiversity of heterotrophic viable bacteria (209 isolates) in the hypersaline Bardawil Lagoon, Egypt, was studied. Composition and extracellular activities of viable culturable heterotrophic bacteria (VCHB) in the water and in non-colonised and seagrass-colonised sediments of Bardawil Lagoon were determined...

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Flood effects on trophic linkages of selected fish species in the littoral zone of the St Lucia estuarine system, South Africa

Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: N Peer --- School of Life Sciences, South Africa NK Carrasco --- School of Life Sciences, South Africa R Perissinotto --- School of Life Sciences, South Africa SJ du Plooy --- School of Life Sciences, South Africa

The St Lucia Estuary, a UNESCO World Heritage Site, has experienced prolonged mouth closure since 2002. Until recently it was hypersaline, but heavy rainfall between October 2010 and January 2011 led to a large overall decrease in salinity. A stable...

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The Effect of Nitroacta (Urea Formaldehyde) on the Growth and Development of Eucalyptus grandis and Pinus elliottii

Item type: Journal Article • Journal: South African Forestry Journal • Authors: R.F. Loxton D. G.M. Donald

A pot trial testing the effect of four rates of urea formaldehyde, applied in two forms, on the growth of Eucalyptus grandis and Pinus elliottii is described. It is concluded that the eucalypt responded linearly to this slow-acting nitrogen source...

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APPLICATION OF LAVSOE, AN EUTROPHICATION MODEL, TO BLOEMHOF DAM

Item type: Journal Article • Journal: Southern African Journal of Child and Adolescent Mental Health • Authors: J.N. Rossouw --- ,

In 1985 the Department of Water Affairs introduced an effluent phosphate standard of 1 mg l−1 (as P) in seven potentially sensitive catchments. Although this is an uniform standard, permits can be granted for effluents to exceed the standard in...

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Uptake and accumulation of ammonium by Alexandrium catenella during nutrient pulses

Item type: Journal Article • Journal: African Journal of Marine Science • Authors: Y Collos M Lespilette A Vaquer M Laabir A Pastoureaud

Field observations in Thau Lagoon, southern France, indicate that the growth of natural populations of Alexandrium catenella during blooms is limited by nitrogen and exhibits a storage rather than a growth response to an ammonium pulse. Therefore, ammonium uptake and...

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Contribution by microbes to the foodweb of a mangrove biotope: the approach of carbon and nitrogen stable isotopes

Item type: Journal Article • Journal: African Journal of Marine Science • Authors: MA Nabeel --- , India K Kathiresan --- , India N Rajendran --- , India H Ohnishi --- , Japan H Hamaoka --- , Japan K Omori --- , Japan

The contribution of mangroves as a source of nutrients to the foodweb of fish is under debate worldwide. An analysis of stable isotopes of carbon and nitrogen in various consumers and producers of a mangrove biotope in southern India revealed...

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Ecosystem considerations of the KwaZulu-Natal sardine run

Item type: Journal Article • Journal: African Journal of Marine Science • Authors: L Hutchings --- Oceans and Coasts, Department of Environmental Affairs, South Africa T Morris --- Bayworld, Port Elizabeth Museum, South Africa CD van der Lingen --- Marine Research Institute, South Africa SJ Lamberth --- Branch Fisheries, Department of Agriculture, South Africa AD Connell --- , South Africa S Taljaard --- , South Africa L van Niekerk --- , South Africa

The annual winter sardine run along the South African east coast impacts the KwaZulu-Natal (KZN) coastal system in a variety of ways. These include ecological impacts, such as enrichment of a largely oligotrophic environment, competition between migrant sardine Sardinops sagax,...

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Responses of Eucalyptus species to fertilizer applications made at planting on granitic parent materials in the Mpumalanga and Northern Provinces of South Africa

Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: ColleenA. Carlson --- , South Africa Ross Allan --- , South Africa Samuel Soko --- , South Africa

Early research trials in South Africa have shown that Eucalyptus species generally respond positively to the addition of nutrients at planting. However, as most of these research trials were located in KwaZulu-Natal, it was important to investigate the nature ofthe...

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The impact of the addition of Eucalyptus grandis wood chips on nitrogen availability in plantation soils

Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: TheresaL. Bird --- School of Animal, Plant and Environmental Sciences, MaryC. Scholes

The impact of plantation residues, as a result of clearfelling, on nutrient availability in plantation systems, as well as the difficulties during subsequent planting and harvesting, should be considered in the development of plantation management strategies. The aim of this...

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The effect of the colonisation extent of arbuscular mycorrhizal fungi on the growth of pot grown Pterocarpus angolensis seedlings

Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: S.N. Hengar --- Department of Forest Science, USA A.J. Valentine --- Department of Environmental Science, USA J.M. Theron --- Department of Forest Science, USA

The effect of the level of arbuscular mycorrhizal fungi (AMF) colonisation on the growth of Pterocarpus angolensis was studied. Mycorrhizal infected seedlings, showing either good or poor growth, under the same environmental conditions (temperature, humidity, light level) were analyzed for...

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Effect of an impoundment on nutrient dynamics in the Kihansi River, Tanzania

Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: RJ Ideva J Machiwa F Schiemer T Hein

The impact of the Kihansi Dam on electrical conductivity, pH, temperature and dissolved oxygen in the Kihansi River was assessed in 2005 after 85% of the original river flow had been diverted to the Lower Kihansi power plant. The results...

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Rapid assessment of tissue nitrogen in cultivated Gracilaria gracilis (Rhodophyta) and Ulva lactuca (Chlorophyta)

Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: DV Robertson-Andersson --- Botany Department, South Africa DT Wilson --- Botany Department, South Africa JJ Bolton --- Botany Department, South Africa RJ Anderson --- Botany Department, South Africa GW Maneveldt --- Department of Biodiversity and Conservation Biology, South Africa

Tissue nitrogen content and thallus colour were quantified using a rapid assessment method based on the Pantone® matt uncoated formula guide for raft-cultivated Gracilaria gracilis Steentoft, Irvine ef Farnham at Saldanha Bay and tank-cultivated Ulva lactuca Linnaeus at Jacobsbaai in...

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Seasonal nutrient fluctuation in selected plant species in the Kalahari

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: FH Stapelberg MW van Rooyen J du P Bothma

Seasonal changes in crude protein, phosphorus and calcium contents of five common plant species in the south-western Kalahari were investigated. Three species that are browsed by springbok (Acacia erioloba, Grewia flava and Rhigozum trichotomum) and two grass species (Schmidtia kalahariensis...

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Nitrogen uptake of a perennial ryegrass–white clover pasture following strategic nitrogen fertiliser application during the cool seasons in the Western Cape province, South Africa

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: J Labuschagne MB Hardy GA Agenbag

The effect of four fertiliser nitrogen (N) levels (0, 50, 100 or 150 kg N ha−1) applied as a single dressing in either autumn (late April), early winter (early June), late winter (mid July), early spring (late August) or late...

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Different responses of Eragrostis curvula and Themeda triandra to rapid- and slow-release fertilisers: insights into their ecology and implications for fertiliser selection in pot experiments

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: RWS Fynn J Naiken

In a pot experiment, we examined the response of Eragrostis curvula and Themeda triandra to 0, 15, 30 and 60 g m−2 of nitrogen (N) supplied either as a rapid-release fertiliser (Sasol Nitro NPK) or a slow-release fertiliser (Plantacote Plus)...

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Estimation of true intestinal digestibility of dry matter, nitrogen and amino acids of cowpea and silverleaf desmodium forage legumes and Brachystegia spiciformis (musasa) browse legume

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: JJ Baloyi --- Department of Animal Science, Zimbabwe H Hamudikuwanda --- Department of Animal Science, Zimbabwe NT Ngongoni --- Department of Animal Science, Zimbabwe

True intestinal digestibility of dry matter (DM), rumen-undegraded dietary protein (UDP) and amino acids of cowpea, silverleaf desmodium and Brachystegia spiciformis (musasa) were estimated. The true intestinal digestibility was calculated as the difference between the content of a bag that...

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The effect of nitrogen and sulphur on the grain yield and quality of canola (Brassica napus L.) grown in the Western Cape, South Africa

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Wonder Ngezimana --- Department of Agronomy, South Africa Gert A Agenbag --- Department of Agronomy, South Africa

On average low grain yields of less than 1.5 t ha-1 are obtained with canola in the Western Cape province of South Africa. Injudicious use of fertiliser has been suggested as a major cause, hence the study was done to...

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The future of warm-season, tropical and subtropical forage legumes in sustainable pastures and rangelands

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: James P Muir --- Borlaug Institute, South Africa William D Pitman --- Hill Farm Research Station, USA Jose C Dubeux --- Universidade Federal Rural de Pernambuco, Brazil Jamie L Foster --- Texas A&M AgriLife Research, USA

Forage legumes have the potential to contribute substantially to warm-season, subtropical and tropical pastures and rangelands. Compared to grasses, they have advantages in accessing subsoil nutrients and moisture; legumes typically concentrate protein in forage, even in infertile soils, and they...

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Trophic investigations of Cape fur seals at the easternmost extreme of their distribution

Item type: Journal Article • Journal: African Journal of Marine Science • Authors: M Connan --- Department of Zoology, South Africa GJG Hofmeyr --- Department of Zoology, South Africa MJ Smale --- Department of Zoology, South Africa PA Pistorius --- Department of Zoology, South Africa

The diet of Cape fur seals Arctocephalus pusillus pusillus in the eastern portion of their distribution has received little attention previously, and was studied using traditional methods only. In 2013 we therefore assessed the diet of seals at the easternmost...

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Changes in density and composition of algal assemblages in certain unit processes of two South African water purification plants

Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: MGJ Oosthuizen --- Unit for Environmental Sciences and Management, South Africa S Janse van Vuuren --- Unit for Environmental Sciences and Management, South Africa

The water purification plants at Virginia and Bothaville, South Africa, experience problems with cyanobacteria and other algae. Their algal assemblages were studied during 2010 and 2011 to determine the dominant species that may pose problems in purification. Cyanobacteria, diatoms and...

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Can δ¹⁵N and δ¹³C stable isotopes and fatty acid signatures indicate changes in phytobenthos composition on an artificial substrate?

Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: T Dalu --- Department of Zoology and Entomology, South Africa PW Froneman --- Department of Zoology and Entomology, South Africa

Temporal changes in fatty acid composition and δ15N, δ13C stable isotope values of the phytobenthos growing on artificial clay substrates under natural conditions over a 28-day period at an upstream and a downstream site in the Kowie River near Grahamstown...

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Soil organic carbon and nitrogen stocks along a seasonal wetland (dambo) transect in central Zimbabwe

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: George Nyamadzawo --- Department of Soil Science and Agricultural Engineering, Zimbabwe Menas Wuta --- Department of Soil Science and Agricultural Engineering, Zimbabwe Justice Nyamangara --- International Crops Research Institute for the Semi Arid Tropics, Matopos Research Station, Zimbabwe Philip Nyamugafata --- Department of Soil Science and Agricultural Engineering, Zimbabwe

Ecosystems of central and southern Africa are occupied by some of the largest seasonal wetlands commonly called dambos. Dambos are likely to store huge stocks of soil organic carbon (SOC) because of their saturated conditions. However, most available literature report...

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Incorporating stable isotopes into a multidisciplinary framework to improve data inference and their conservation and management application

Item type: Journal Article • Journal: African Journal of Marine Science • Authors: HM Christiansen --- Great Lakes Institute for Environmental Research, Canada AT Fisk --- Great Lakes Institute for Environmental Research, Canada NE Hussey --- Great Lakes Institute for Environmental Research, Canada

Through its ability to address complex ecological questions and the possibility of analysing large sample sizes to understand population‑level processes, the use of stable isotope analysis (δ13C and δ15N) has grown rapidly in recent years. Importantly, it is now becoming...

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Optimisation of nitrogen and potassium for Aloe vera (L.) Burm.f. in a soilless culture system

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Jamal-Ali Olfati --- Horticultural Department, Iran Mohammad Saadatian --- Department of General Science, Faculty of Education, Iraq Eshaq Moqbeli --- Horticultural Department, Iran

Aloe vera (L.) Burm.f. is highly appreciated due to its short growth period and high economic value among all Aloe species, and is used in pharmaceuticals, folk medicine, healthcare, cosmetic products and food products. Hydroponic systems have the potential to...

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Assessing the potential benefits of organic and mineral fertiliser combinations on legume productivity under smallholder management in Zimbabwe

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Grace Kanonge --- Chemistry and Soils Research Institute, Zimbabwe Florence Mtambanengwe --- Soil Fertility Consortium for Southern Africa (SOFECSA), Department of Soil Science and Agricultural Engineering, Zimbabwe Muneta G Manzeke --- Soil Fertility Consortium for Southern Africa (SOFECSA), Department of Soil Science and Agricultural Engineering, Zimbabwe Hatirarami Nezomba --- Soil Fertility Consortium for Southern Africa (SOFECSA), Department of Soil Science and Agricultural Engineering, Zimbabwe Paul Mapfumo --- Soil Fertility Consortium for Southern Africa (SOFECSA), Department of Soil Science and Agricultural Engineering, Zimbabwe

Productivity of grain legumes on sandy soils of southern Africa is critically limited by marginal fertilisation. Effects of co-applying phosphorus (P)-based mineral fertilisers and organic nutrient resources to cowpea (Vigna unguiculata (L.) Walp.) and soyabean (Glycine max L.) were investigated...

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Changes in the algal composition and water quality of the Sundays River, Karoo, South Africa, from source to estuary

Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: S Janse van Vuuren --- Unit for Environmental Sciences and Management, South Africa JC Taylor --- Unit for Environmental Sciences and Management, South Africa

A first survey was done on algae present in the Sundays River from its source to its confluence with the sea. Species found in the upstream sections of the river included indicators of good water quality, but the quality deteriorated...

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Saldanha Bay, South Africa III: new production and carrying capacity for bivalve aquaculture

Item type: Journal Article • Journal: African Journal of Marine Science • Authors: TA Probyn --- Aquaculture Research, Department of Agriculture, Forestry and Fisheries, South Africa JF Atkins --- Department of Oceanography, South Africa GC Pitcher --- Aquaculture Research, Department of Agriculture, Forestry and Fisheries, South Africa

Measurements of NH4, NO3, urea and HCO3 uptake using 15N and 13C stable isotope tracers were undertaken in Saldanha Bay, South Africa, between January 2012 and January 2013. These studies provide the first direct measurements of N utilisation by the...

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Predicting soil nitrogen content using narrow-band indices from Eucalyptus grandis canopies as proxy

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Thamsanqa Mzinyane --- University of KwaZulu-Natal, South Africa Jan van Aardt --- Rochester Institute of Technology, UK Fethi Ahmed --- University of Witswatersrand, South Africa Michael Gebreslasie --- School of Agriculture, Earth and Environmental Science, South Africa

Optimal fertiliser applications for sustainable forest stand productivity management, whilst protecting the environment, is vital. This study estimated soil nitrogen content using leaf-level narrow-band vegetation indices derived from a hand-held 350-2 500 nm spectroradiometer. Leaf-level spectral data were collected and subjected...

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Soil water and mineral nitrogen content as influenced by crop rotation and tillage practice in the Swartland subregion of the Western Cape

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Japie D Wiese --- Department of Agronomy, South Africa Johan Labuschagne --- Directorate Plant Science, South Africa Gert A Agenbag --- Department of Agronomy, South Africa

Adoption of conservation agricultural practices, reduced tillage and crop rotation in the grain-producing areas of the Western Cape, South Africa, resulted in a gradual build-up of organic matter on the soil surface. It was expected that the increase in organic...

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Shade tolerance and suitability of tree species for planting in rubber plantations

Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Yaohua Tian --- Yunnan Institute of Tropical Crops, China Huifang Yuan --- Yunnan Institute of Tropical Crops, China Jiang Xie --- Yunnan Institute of Tropical Crops, China Yulong Zheng --- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, China

The rapid increase in rubber monoculture in Xishuangbanna has resulted in extensive damage to its local ecosystem. To decrease the negative effects, the concept of the ecological-economic rubber plantation (EERP) system was proposed. The EERP entails intercropping rubber plants with...

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Effect of soil amendments on yield of wild okra (Corchorus olitorius) in northern KwaZulu-Natal, South Africa

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Sydney Mavengahama --- Department of Agriculture, Faculty of Science and Agriculture, South Africa Willem P de Clercq --- Department of Soil Science, Faculty of AgriSciences, South Africa Milla McLachlan --- Division of Human Nutrition, Faculty of Medicine and Health Sciences, South Africa

The consumption of semi-domesticated indigenous vegetables such as Corchorus olitorius is being promoted in South Africa. Presently, cultivation of indigenous vegetables is hampered by the absence of cultivation guidelines due to lack of agronomic research on the various production aspects...

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Riverine influence determines nearshore heterogeneity of nutrient (C, N, P) content and stoichiometry in the KwaZulu-Natal Bight, South Africa

Item type: Journal Article • Journal: African Journal of Marine Science • Authors: UM Scharler --- School of Life Sciences, South Africa MJ Ayers --- School of Life Sciences, South Africa AM de Lecea --- School of Life Sciences, South Africa M Pretorius --- Department of Biodiversity and Conservation Biology, South Africa ST Fennessy --- Oceanographic Research Institute, South Africa JA Huggett --- Branch: Oceans and Coasts, Department of Environmental Affairs, South Africa CF MacKay --- Oceanographic Research Institute, South Africa D Muir --- Medgar Evers College, USA

Riverine influences on nearshore oceanic habitats often have detrimental consequences leading to algal blooms and hypoxia. In oligo- to mesotrophic systems, however, nutrient delivery via rivers may stimulate production and even be a vital source of nutrients, as may nutrient...

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Evaluation of the effects of phosphorus and nitrogen source on aerial and subsoil parameters of maize (Zea mays L.) during early growth and development

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Pieter-Ernst Coetzee --- Department of Soil, Crop and Climate Sciences, South Africa Gert M Ceronio --- Department of Soil, Crop and Climate Sciences, South Africa Chris C du Preez --- Department of Soil, Crop and Climate Sciences, South Africa

Understanding the nutrient requirements of maize is especially important during early vegetative growth and development, particularly when produced on highly weathered soils with low organic matter contents. Therefore, the growth response of maize to different nitrogen (N) sources viz. limestone...

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$Optical chlorophyll measurements as predictors of total nitrogen, nitrogen fractions and <em>in vitro</em> ruminal nitrogen degradability in tropical grass forages$

Optical chlorophyll measurements as predictors of total nitrogen, nitrogen fractions and in vitro ruminal nitrogen degradability in tropical grass forages

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Martin Hughes --- Department of Food Production, Trinidad and Tobago Victor Mlambo --- Department of Animal Science, South Africa Cicero HO Lallo --- Department of Food Production, Trinidad and Tobago Paul GA Jennings --- MARJEN Consulting Group, Jamaica

This study evaluated whether the FieldScout CM 1000 NDVI and Yara N–Tester models can produce accurate and reliable estimates of nitrogen (N), buffer-soluble nitrogen (BSN), buffer-insoluble nitrogen (BISN), non-protein nitrogen (NPN) and in vitro ruminal nitrogen degradability after 3, 12...

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The effects of conservation tillage practices and fertiliser management on soil structural properties at an experimental farm

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Danie Beukes --- Agricultural Research Council–Institute for Soil, Climate and Water, South Africa Corrie Swanepoel --- Agricultural Research Council–Institute for Soil, Climate and Water, South Africa

Crop rotation and reduced tillage under conservation agriculture (CA) practices may induce higher soil organic carbon (SOC) and nitrogen (N) levels compared with conventional (Con) tillage practices. Soil organic carbon may increase soil aggregate stability (AS). The study site was...

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Comparison of soil properties under tropical Acacia hybrid plantation and shifting cultivation land use in northern Vietnam

Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Trieu Thai Hung --- Tasmanian Institute of Agriculture and School of Land and Food, Australia Richard Doyle --- Tasmanian Institute of Agriculture and School of Land and Food, Australia Alieta Eyles --- Tasmanian Institute of Agriculture and School of Land and Food, Australia Caroline Mohammed --- Tasmanian Institute of Agriculture and School of Land and Food, Australia

Despite the common use of Acacia species in Vietnam, few studies have examined changes to total soil nitrogen (TN) and total soil carbon (TC) following the planting of Acacia mangium × Acacia auriculiformis (Acacia hybrid) plantations (AH) on formerly eroded...

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Season, sex and age variation in the haematology and body condition of geometric tortoises Psammobates geometricus

Item type: Journal Article • Journal: African Zoology • Authors: Margaretha D Hofmeyr --- Chelonian Biodiversity and Conservation – Southern Africa, Biodiversity and Conservation Biology Department, South Africa Brian T Henen --- Chelonian Biodiversity and Conservation – Southern Africa, Biodiversity and Conservation Biology Department, South Africa Shasheen Walton --- Chelonian Biodiversity and Conservation – Southern Africa, Biodiversity and Conservation Biology Department, South Africa

Body condition and haematological indices provide powerful information when assessing wildlife health. Reference intervals for these indices can facilitate wildlife management, and would benefit initiatives to save the Critically Endangered geometric tortoise (Psammobates geometricus). We collected data from 126 geometric...

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Soil fertility and growth of Eucalyptus grandis in Brazil under different residue management practices

Item type: Journal Article • Journal: Southern Hemisphere Forestry Journal • Authors: JLM Gonçalves MCP Wichert JL Gava AV Masetto ArthurJ.C. Junior MIP Serrano SLM Mello

Silvicultural operations such as soil preparation, logging residue management and application of fertilisers can influence soil fertility, and hence nutrient uptake and tree growth. This paper reports the effect of site management practices of minimum and intensive cultivation of the...

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Seasonal and sub-seasonal oxygen and nutrient fluctuations in an embayment of an eastern boundary upwelling system: St Helena Bay

Item type: Journal Article • Journal: African Journal of Marine Science • Authors: GC Pitcher --- Fisheries Management Branch, Department of Agriculture, Forestry and Fisheries, South Africa TA Probyn --- Fisheries Management Branch, Department of Agriculture, Forestry and Fisheries, South Africa

Seasonal, sub-seasonal and spatial fluctuations in bottom dissolved oxygen (DO) were examined in St Helena Bay, South Africa’s largest and most productive embayment, between November 2013 and November 2014. Alongshore bay characteristics were assessed through comparison of variables along the...

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Productivity of non-heading Chinese cabbage (Brassica rapa subsp. chinensis) under different agronomic management factors

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Innocent Maseko --- University of South Africa, South Africa Yacob G Beletse --- Agricultural Research Council–Vegetable and Ornamental Plant Institute, South Africa Noluyolo Nogemane --- University of South Africa, South Africa Christian P du Plooy --- Agricultural Research Council–Vegetable and Ornamental Plant Institute, South Africa Tatenda R Musimwa --- Crop Science, School of Agricultural, Earth and Environmental Sciences, South Africa Tafadzwanashe Mabhaudhi --- Crop Science, School of Agricultural, Earth and Environmental Sciences, South Africa

Productivity of non-heading Chinese cabbage (Brassica rapa L. subsp. chinensis) was evaluated at Roodeplaat over two winter seasons (2012 and 2013). Agronomic factors considered were plant density, nitrogen level, irrigation frequency and planting date. Irrigating thrice or once a week...

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Effect of residue and fertiliser management on soil fertility in a long-term sugarcane trial in South Africa

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Sandile Mthimkhulu --- South African Sugarcane Research Institute, South Africa Neil Miles --- South African Sugarcane Research Institute, South Africa Rianto van Antwerpen --- South African Sugarcane Research Institute, South Africa Dimpho Elephant --- South African Sugarcane Research Institute, South Africa

Understanding the impact of long-term continuous addition of sugarcane residues and fertiliser on soil fertility is important for development of best management practices. The experiment commenced in 1939. The fertility of the 0–10 cm soil layer was affected by the...

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Wintertime rates of net primary production and nitrate and ammonium uptake in the southern Benguela upwelling system

Item type: Journal Article • Journal: African Journal of Marine Science • Authors: RF Flynn --- Department of Oceanography, South Africa JM Burger --- Department of Oceanography, South Africa K Pillay --- Branch: Oceans and Coasts, Department of Environmental Affairs (DEA), South Africa SE Fawcett --- Department of Oceanography, South Africa

The elevated levels of primary productivity associated with eastern boundary currents are driven by nutrient- rich waters upwelled from depth, such that these regions are typically characterised by high rates of nitrate-fuelled phytoplankton growth. Production studies from the southern Benguela...

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Biological soil crusts of the Succulent Karoo: a review

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Bettina Weber --- Max Planck Institute for Chemistry, Germany Alexandra Tamm --- Max Planck Institute for Chemistry, Germany Stefanie Maier --- Max Planck Institute for Chemistry, Germany Emilio Rodríguez-Caballero --- Department of Desertification and Geo-Ecology, Experimental Station of Arid Zones (EEZA-CSIC), Spain

The Succulent Karoo is characterised by a dense coverage of biological soil crusts (biocrusts) belonging to different types and successional stages. Whereas the Soebatsfontein region hosts cyanobacteria-dominated and minor amounts of lichen- and bryophyte-dominated biocrusts, the Knersvlakte comprises a rich...

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Response of two wheat cultivars to inoculation of diazotrophic bacteria in combination with reduced nitrogen fertilisation under field conditions

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Reannah RN Otanga --- Discipline of Plant Pathology, School of Agriculture, Earth and Environmental Sciences, South Africa Kwasi S Yobo --- Discipline of Plant Pathology, School of Agriculture, Earth and Environmental Sciences, South Africa Mark D Laing --- Discipline of Plant Pathology, School of Agriculture, Earth and Environmental Sciences, South Africa

Chemical fertilisers are essential for plant nutrition in attaining desired yields. However, increased cost of fertiliser input has made it impossible for small-scale farmers to properly fertilise their crops for optimum yields. Five bacterial strains originally isolated from no-till agricultural...

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Growth and yield responses of two ginger species to different levels of nitrogen

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Auges Gatabazi --- Department of Plant and Soil Sciences, South Africa Diana Marais --- Department of Plant and Soil Sciences, South Africa J Martin Steyn --- Department of Plant and Soil Sciences, South Africa Hintsa T Araya --- Agricultural Research Council–Vegetable and Ornamental Plants, South Africa Salmina N Mokgehle --- Agricultural Research Council–Vegetable and Ornamental Plants, South Africa

Nitrogen (N) is a critical determinant of plant growth and productivity, but there is limited information on the agronomic parameters of medicinal plants. Three levels of N fertiliser (0, 1.375 and 1.625 g plant−1) were used to investigate the effects...

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Nitrogen Deficiency in Semi-Arid Kenya: Can Pigeonpea fix it?

Item type: Journal Article • Journal: East African Agricultural and Forestry Journal • Authors: K. Kwena --- University of Nairobi, Kenya G. N. Karuku --- University of Nairobi, Kenya F. O. Ayuke --- University of Nairobi, Kenya A. O. Esilaba --- Kenya Agricultural & Livestock Research Organization (KALRO), Kenya

Few studies have evaluated improved pigeonpea varieties developed and released in Kenya for soil fertility improvement and contribution to the productivity of cereal-based cropping systems prevalent in marginal areas. A study comprising field and greenhouse experiments was conducted between 2009...

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Impact of long-term production management practices on wheat grain yield and quality components under a semi-arid climate

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: MK Seepamore --- , South Africa CC du Preez --- , South Africa GM Ceronio --- , South Africa

Wheat production in South Africa has declined significantly over the past three decades making the country a nett importer of wheat. Proper production management practices are needed to counter this trend. The aim of the study was therefore to determine...

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Spatial and ontogenetic variability in the diet and trophic ecology of two co-occurring catsharks (Scyliorhinidae) off South Africa

Item type: Journal Article • Journal: African Journal of Marine Science • Authors: GM van der Heever --- , South Africa CD van der Lingen --- , South Africa RW Leslie --- , South Africa MJ Gibbons --- , South Africa

The Izak catshark Holohalaelurus regani and the yellow-spotted catshark Scyliorhinus capensis both occur over the continental shelf around South Africa and are often caught together as bycatch in demersal trawls. Yet our understanding of their diet is fragmented, which makes...

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$Low nitrogen fertiliser rates and stage of maturity influence nitrogen fractionation and <em>in vitro</em> ruminal nitrogen degradability in tropical grasses$

Low nitrogen fertiliser rates and stage of maturity influence nitrogen fractionation and in vitro ruminal nitrogen degradability in tropical grasses

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Martin P Hughes --- , Trinidad and Tobago Victor Mlambo --- , South Africa Cicero HO Lallo --- , Trinidad and Tobago

This study evaluated the interactive effects of low rates (0, 25, 50 and 75 kg N ha−1) of nitrogen (N) fertilizer application and stage of maturity on total N, N fractions and in vitro ruminal N degradability in Brachiaria hybrid,...

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Nitrogen mineralisation and N₂O emissions in pure and mixed-species plantations of Eucalyptus urograndis and Acacia mangium

Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Felipe Martini Santos --- , Brazil Fabiano de Carvalho Balieiro --- , Brazil Danilo Henrique dos Santos Ataíde --- , Brazil Pedro Vaz da Rocha --- , Brazil Bruno JR Alves --- , Brazil Guilherme M Chaer --- , Brazil

We hypothesised that N inputs to the soil from residues of adult trees of Acacia mangium Willd. increase soil nitrate availability and consequently induce higher nitrous oxide (N2O) fluxes, irrespective of being in pure or mixed stands with Eucalyptus. A...

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Evaluating the effects and benefits of cover crops in citrus orchards: a review

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Sibongiseni Silwana --- ARC Infruitec-Nietvoorbij, South Africa Azwimbavhi Reckson Mulidzi --- ARC Infruitec-Nietvoorbij, South Africa Nebo Jovanovic --- University of the Western Cape, South Africa

Cover crops are used in sustainable agricultural practices to improve soil quality and minimise the effect of climate change, water restrictions and drought. The South African citrus industry produces and exports a diverse range of citrus fruits; however, knowledge of...

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Associative nitrogen fixation could be common in South African mesic grassland

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: --- University of KwaZulu-Natal, South Africa --- University of KwaZulu-Natal, South Africa --- Institute for Commercial Forestry Research, South Africa

Non-symbiotic nitrogen-fixing bacterial diazotrophs closely associated with the roots of grasses probably contribute most of the new nitrogen acquired to sustain productive natural grasslands, yet their ecology is poorly understood, especially in southern Africa. We looked for genetic evidence, using...

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Nutritional properties and in vitro gas production in cactus pear (Opuntia stricta) and cassava (Manihot esculenta) shoot silages

Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: --- Universidade Federal do Vale do São Francisco, Brazil --- Universidade Federal do Agreste de Pernambuco, Brazil --- Universidade Federal do Vale do São Francisco, Brazil --- Universidade Estadual do Sudoeste da Bahia, Brazil --- Universidade Federal do Tocantins, Brazil --- Universidade Federal do Agreste de Pernambuco, Brazil --- Universidade Federal do Agreste de Pernambuco, Brazil --- Universidade Federal do Agreste de Pernambuco, Brazil --- , Brazil --- Universidade Federal do Maranhão, Brazil --- Universidade Federal do Vale do São Francisco, Brazil

This study evaluated the effects of different inclusion levels of cactus pear (Opuntia stricta) (at 0%, 15%, 30% or 45% on fresh matter basis) ensiled with shoots of cassava (Manihot esculenta) on the mineral nutrients, carbohydrates fractionation, nitrogen compounds and...

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Analysis of freshwater diatom deformities in the Karoo, South Africa

Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: M Holmes --- Nelson Mandela University, South Africa EE Campbell --- Nelson Mandela University, South Africa M de Wit --- Africa Earth Observatory Network (AEON) – Earth Stewardship Science Research Institute (ESSRI) Nelson Mandela University, South Africa JC Taylor --- North-West University, South Africa

Several studies regarding the effects of excess nutrients and metals as possible causes of deformities found in diatom cells have been conducted in Europe, North America and Australia. This is the first study in South Africa which catalogued and analysed...

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Nitrogen fertiliser demand of canola is low when produced in conservation agriculture systems in South Africa

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Izané Riana Crous --- Stellenbosch University, South Africa Johan Labuschagne --- Stellenbosch University, South Africa Pieter Andreas Swanepoel --- Stellenbosch University, South Africa

Current fertiliser guidelines for nitrogen (N) application for canola under conservation agriculture (CA) in South Africa, may result in over-fertilisation. This study aimed to evaluate the effects of N rates and foliar applied N on biomass, seed and oil yield...

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Nitrogen requirements of canola (Brassica napus L.) at sustained deficit irrigation levels in central Free State, South Africa

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: KA Seetseng --- University of the Free State, South Africa JH Barnard --- University of the Free State, South Africa CC du Preez --- University of the Free State, South Africa

In South Africa canola (Brassica napus L.) is cultivated in rotation with wheat under winter rainfall in the Western Cape province. Expansion of the crop to the other eight provinces is propagated to reduce a shortage of locally produced plant...

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Are inorganic nitrogen concentrations in potassium chloride and saturated paste extracts of irrigated soils comparable?

Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: D Steenekamp --- University of the Free State, South Africa LD van Rensburg --- University of the Free State, South Africa JH Barnard --- University of the Free State, South Africa CC du Preez --- University of the Free State, South Africa

Precision agriculture is gaining momentum in irrigation through the assessment of soil salinity variability, often facilitated by electromagnetic induction (EMI) sensors. This study aimed to evaluate whether saturated paste extracts (SATe) could serve as a substitute for the standard 2...

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Intrapopulation isotopic niche structure in mammalian carnivores and herbivores across contrasting habitats

Item type: Journal Article • Journal: African Zoology • Authors: Chanel Lewis --- University of the Free State, South Africa Runè van der Merwe --- University of the Free State, South Africa Chabi AMS Djagoun --- University of Abomey-Calavi, Benin Etotépé A Sogbohossou --- University of Abomey-Calavi, Benin Daryl Codron --- University of the Free State, South Africa

Natural communities exhibit ecological gradients that result in a variety of competitive interactions and variations in niche patterns. Changes in resource availability affect the size of a species’ niche: it expands when a variety of resources are abundant and contracts...

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Assessment of near-infrared reflectance spectroscopy for monitoring soil carbon, nitrogen and organic matter in South African forestry plantations

Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: DR Ramesar --- Institute for Commercial Forestry Research, South Africa DS Naidoo --- Institute for Commercial Forestry Research, South Africa GD Cooper --- Institute for Commercial Forestry Research, South Africa RJ Burgdorf --- Institute for Commercial Forestry Research, South Africa

Soil organic matter, carbon and nitrogen contribute to soil quality, which influences plant growth. In forestry planta- tions soil carbon, nitrogen and organic matter significantly influence site productivity. In South Africa, plantation forestry occurs across a diverse landscape requiring assessment...

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