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Physical and clay mineralogical properties of some Natal and eastern Transvaal soils
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A. Cass --- , Australia M.A. Johnston --- Department of Agriculture and Water Supply,Soils, collected from the south-eastern Transvaal, Natal north coast and the more arid areas of the Natal interior, were examined using physical, chemical and mineralogical methods. Most of the soils were associated with particular management problems such as poor internal... -
A turbidimeter for measuring soil-particle concentration in suspensions
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: D.J. Nel --- Department of Soil Science, Republic of South Africa E.P. Blignaut --- Department of Electronic Services, Republic of South AfricaA turbidimeter was designed and constructed to determine the degree of dispersion associated with different treatments of soil samples in suspension. Measurement is based on the transmission of light through a dispersed soil suspension. The experimental array of light source,... -
Effect of soil surface amendments on runoff and erosion from simulated rain applied to a sesquioxidic soil
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: H. Frenkel --- Department of Agronomy, Republic of South Africa M.V. Fey --- Department of Agronomy, Republic of South Africa G.H. Goodall --- Department of Agronomy, Republic of South Africa W.B. Russell --- Department of Agriculture and Water Supply, Republic of South AfricaSimulated rainfall, using low conductivity water, was applied at an intensity of 63 mm h−1 to a field soil of the Doveton series (a kaolinitic, sesquioxidic clay soil at Cedara in Natal, recently cultivated out of pasture) after pre-treatment of... -
Polymer effect on infiltration and erosion of sodic soils
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M. Gal --- , Republic of South Africa R. Stern --- , Republic of South Africa J. Levin --- , Republic of South Africa M. Ben-Hur --- , Republic of South AfricaRunoff from irrigated sodic soils is a common phenomenon in arid and semi-arid climates. The effect of a low-charge polysaccharide (LCCP) on infiltration rate (IR) and runoff on two red apedal soils was studied using an irrigation simulator. One was... -
The effect of hydroxide solutions on the structural stability and saturated hydraulic conductivity of four tropical soils
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Nyamangara --- Department of Soil Science and Agricultural Engineering, Zimbabwe S. Munotengwa --- Department of Soil Science and Agricultural Engineering, Zimbabwe P. Nyamugafata --- Department of Soil Science and Agricultural Engineering, Zimbabwe G. Nyamadzawo --- Department of Soil Science and Agricultural Engineering, ZimbabweIndustrial and domestic effluents are widely applied to soil as a way of dumping, and/or source of nutrients and water for plant growth. The potential effects of sodium hydroxide (NaOH) and potassium hydroxide (KOH), which are common hydroxides found in... -
Relationships between soil particle size fractions and infiltrability
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: T.V. Medinski --- Department of Soil Science, South Africa A.J. Mills --- Department of Soil Science, South Africa M.V. Fey --- , Western AustraliaThe influence of particle size fractions on infiltrability was investigated in soils sampled across Namibia and western South Africa. Infiltrability was determined using a laboratory technique calibrated with rainfall simulation, which measures the passage of a suspension of soil particles... -
DISSEMINATION OF AQUATIC INVERTEBRATES ON WINDBLOWN VEGETATION MATS IN LAKE CHILWA, MALAWI
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: M.A. Cantrell --- Lake Chilwa Co-ordinated Research Project, MalaŵiExceptionally high water levels in Lake Chilwa, Malaŵi, resulted in large tracts of the swamp vegetation becoming detached from the periphery of the lake. The open water became littered with large rafts of the bulrush, Typha domingeneis together with other... -
The relation between herbivore density and relative resource density at the landscape level: Kudu in semi‐arid savanna
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: C. Fabricius --- , Republic of South AfricaEcological theory can help range scientists to understand the determinants of ecological animal density or, in range management terms, ‘carrying capacity’. The relation between the relative density of resources and herbivore density is illustrated by regressions of the ecological density... -
Understanding the combined effect of soil properties on gully erosion using quantile regression
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: George M van Zijl --- Department of Soil Science, South Africa Freddie Ellis --- Department of Soil Science, South Africa Andrei Rozanov --- Department of Soil Science, South AfricaThe individual effects of soil properties on soil erodibility are well understood. It is also known that various interactions between these properties exist, which creates the need for unique investigations into how soil properties influence soil stability. Quantile regression was... -
Vagrant Subantarctic fur seal in the Mayumba National Park, Gabon
Item type: Journal Article • Journal: African Zoology • Authors: R. Zanre --- Mayumba Project Manager, Wildlife Conservation Society, Gabon M. N. Bester --- Department of Zoology and Entomology, South AfricaA vagrant adult male Subantarctic fur seal Arctocephalus tropicalis was seen and photographed on the beach in Mayumba National Park in the Gabonese Republic. This is the northern most sighting on record for the species. The likely source of the... -
The influence of food abundance, food dispersion and habitat structure on territory selection and size of an Afrotropical terrestrial insectivore
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: William D Newmark --- Natural History Museum of Utah, USA Thomas R Stanley --- US Geological Survey, USAMost tropical insectivorous birds, unlike their temperate counterparts, hold and defend a feeding and breeding territory year-around. However, our understanding of ecological factors influencing territory selection and size in tropical insectivores is limited. Here we examine three prominent hypotheses relating... -
Colonial versus solitary breeding: nesting patterns of Brown-throated Martins Riparia paludicola in Morocco
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Peter W Greig-Smith --- , United KingdomThis study explored reasons for variable nesting habits in a hole-nesting bird species that sometimes breeds colonially and sometimes alone. Nesting was surveyed over ten years in natural sand cliffs and similar features created by human activity along a river... -
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 AfricaNatural 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...