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Water retentivity of some South African soils in relation to particle size criteria and bulk density
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J.L. Hutson --- ,Retentivity data for 409 South African soils were obtained from several sources. Water retained at matric potential values of 0, −1, −3, −10, −30, −100, −500 and −1500 kPa was determined from the retentivity curve for each soil core. Retentivity... -
Soils derived from granite in two Mt. Garnet toposequences, North Queensland, Australia
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: E. Verster --- Department of Geography, Republic of South AfricaTwo toposequences derived from granite in the Mt. Garnet area, North Queensland, were examined to determine the detailed soil - landform relationships in order to facilitate subsequent broad-scale mapping of the soil resource. The dominant landsurface feature is gently sloping,... -
Interpretation of digital soil photographs using spatial analysis: II. Application
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.W. van Huyssteen --- Department of Soil, Crop and Climate Sciences, South Africa P. A.L. le Roux --- Department of Soil, Crop and Climate Sciences, South Africa M. Hensley --- Department of Soil, Crop and Climate Sciences, South AfricaColour variation in digital photographs of soils was quantified and classified meaningfully, using ArcView Spatial Analyst. This procedure holds great promise for the unbiased and quantitative determination of soil colour properties and statistical correlation with related soil hydrological conditions. The... -
Duration of water saturation in selected soils of Weatherley, South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.W. van Huyssteen --- Department of Soil, South Africa P. A.L. le Roux --- Department of Soil, South Africa M. Hensley --- Department of Soil, South Africa T.B. Zere --- Department of Soil, South AfricaSoil water contents were measured weekly for six years (1997–2005) in the Weatherley catchment in the northern Eastern Cape Province of South Africa, and used to calculate average duration of water saturation above 70% of porosity (ADs>0.7). Data were used... -
A review of advances in hydropedology for application in South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.W. van Huyssteen --- , South AfricaHydropedology is internationally a new and fast-growing science. It is therefore pertinent to take heed of developments in this regard to guide current and future research in South Africa. This paper aims to discuss the initiation and advances in the... -
Modelling crop growth and crop water relations in South Africa: Past achievements and lessons for the future
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A. Singels --- , South Africa J.G. Annandale --- Department of Plant Production and Soil Science, South Africa J.M. De Jager --- Department of Soil, Crop and Climate Sciences, South Africa R.E. Schulze --- , South Africa N.G. Inman-Bamber --- , Australia W. Durand --- , South Africa L.D. Van Rensburg --- Department of Soil, Crop and Climate Sciences, South Africa P.S. Van Heerden --- , South Africa C.T. Crosby --- , South Africa G.C. Green --- , South Africa J.M. Steyn --- Department of Plant Production and Soil Science, South AfricaMathematical simulation of crop growth and water relations has become indispensable to agricultural science and practice. A critical assessment of how modelling has contributed to the development of crop science and to the management of crop production and natural resources... -
Soil indicators of hillslope hydrology in the Bedford catchments, South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J.J. van Tol --- Department of Soil, Crop and Climate Sciences, South Africa P.A.L. Le Roux --- Department of Soil, Crop and Climate Sciences, South Africa M. Hensley --- Department of Soil, Crop and Climate Sciences, South AfricaWater plays a primary role in soil genesis and soil strongly influences hydrological processes (flowpaths, residence times and storage). Morphological soil properties serve as indicators of hillslope hydrological behaviour and can facilitate hydrological predictions. Three catchments in the Bedford district... -
Palmer Drought Indices and Their Application to Plantation Establishment Strategies
Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: J.B. Zwolinski --- ,Palmer drought models are introduced as an objective measure of monthly moisture conditions and their application for forestry research is discussed. A case-study showed that Palmer Hydrological Drought Index was preferred to Palmer Drought Severity Index for deciding on establishment... -
Variations and changes in habitat, productivity, composition of aquatic biota and fisheries of the Kyoga lake system: lessons for management
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: R Ogutu-Ohwayo --- National Fisheries Resources Research Institute, Uganda K Odongkara --- National Fisheries Resources Research Institute, Uganda W Okello --- National Fisheries Resources Research Institute, Uganda D Mbabazi --- National Fisheries Resources Research Institute, Uganda SB Wandera --- National Fisheries Resources Research Institute, Uganda LM Ndawula --- National Fisheries Resources Research Institute, Uganda V Natugonza --- National Fisheries Resources Research Institute, UgandaThe Kyoga lake system, which is c. 4 m deep, originally had a diverse fish fauna, extensive macrophytes and wetlands. Most (82%) of its water comes from Lake Victoria, is controlled through three dams and has a short residence time... -
Water quality and plankton dynamics in two small dams in Zimbabwe
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: Tamuka Nhiwatiwa BrianE MarshallTwo small dams on the Munwahuku River was investigated in relation to the influence of hydrology on their water chemistry over the period January 2000–August 2001. The water level of the upper dam fluctuated more than that of the lower... -
Environmental impact of seasonal integrated aquaculture ponds ('fingerponds') in the wetlands of Lake Victoria, Kenya: an assessment, with the aid of Bayesian Networks
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: Julius Kipkemboi AnneA van Dam Patrick DennyThe potential effect on ecosystem integrity of the use of natural wetlands for seasonal wetland fishponds ('fingerponds'), integrated with vegetable production for livelihood demands, was evaluated using experimental sites at Lake Victoria, Kenya. Soluble reactive phosphorous and total phosphorus, ammonium,... -
Interactions between stream channel incision, soil water levels and soil morphology in a wetland in the Hogsback area, South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Mohammed Y Omar --- Department of Agronomy, South Africa Pieter AL Le Roux --- Department of Soil, Crop and Climate Sciences, South Africa Johan J van Tol --- Department of Agronomy, South AfricaWetland degradation in the form of channel incisioning can significantly alter the hydrological functioning of a wetland. In this study in a small headwater wetland in the Hogsback area, Eastern Cape province, the impact of channel incisioning on soil water... -
Conservation status and distribution of freshwater fishes in South African national parks
Item type: Journal Article • Journal: African Zoology • Authors: I. A. Russell --- South African National Parks, South AfricaThirteen of South Africa’s national parks contain aquatic systems which support 63 indigenous and 11 alien freshwater fishes. Indigenous fishes include 43 species of the Zambezian faunal group (70% of the national total), eight Karroid (47%), five Cape (31%) and... -
Integrating research with management: the case of Katavi National Park, Tanzania
Item type: Journal Article • Journal: African Zoology • Authors: T. Caro --- Department of Wildlife, Fish and Conservation Biology, U.S.A. M. Elisa --- Katavi National Park, Tanzania J. Gara --- Katavi National Park, Tanzania D. Kadomo --- Katavi National Park, Tanzania A. Martin --- Department of Wildlife, Fish and Conservation Biology, U.S.A. D. Mushi --- Katavi National Park, Tanzania C. Timbuka --- Katavi National Park, TanzaniaMany protected areas in Africa and elsewhere suffer from several external pressures making it difficult for management to set priorities. For example, aerial censuses show that many mammal populations in the Katavi-Rukwa ecosystem of western Tanzania are declining. Vehicle transect... -
Design basics of a small hydro turbine plant for capacity building in sub-Saharan Africa
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Williams S. Ebhota --- Department of Mechanical Engineering, South Africa Freddie Inambao --- Department of Mechanical Engineering, South AfricaThis paper presents a simplified design considerations for a propeller hydro-turbine, including tabulated relevant mathematical expressions of operating parameters. In the design calculation, a 2.5 m head and 0.183 m3/s flow rate were used as river data for power of... -
Wetland hydrology indicators of Maluti Mountains wetlands in Lesotho
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Botle E Mapeshoane --- Department of Soil, Crop and Climate Sciences, South Africa Cornelius W van Huyssteen --- Department of Soil, Crop and Climate Sciences, South AfricaHydric soil morphological features are generally accepted to be reliable indicators of wetland hydrology. The relationship between soil water saturation and soil morphological indices is evaluated in this study from bi-weekly water level data taken over a period of two... -
Hydropedological grouping of South African soil forms
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Johan J van Tol --- Department of Soil, Crop and Climate Sciences, South Africa Pieter AL Le Roux --- Institute for Groundwater Studies, University of the Free State, South AfricaThe science of hydropedology has progressed significantly in the past two decades, especially with regards to the interpretation of soil morphology and relating these interpretations to the hydrological behaviour of horizons, profiles, hillslopes and catchments. Soil classification is pivotal to... -
Benthic macrofaunal changes in response to restoration efforts in the St Lucia estuarine lake, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: PC Moloi --- School of Agriculture and Science, University of KwaZulu-Natal, South Africa GM Rishworth --- Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, South Africa MS Bird --- Department of Zoology, University of Johannesburg, South Africa NK Carrasco --- School of Agriculture and Science, University of KwaZulu-Natal, South AfricaThe St Lucia estuarine lake and Mfolozi River mouth on the Indian Ocean coast of South Africa were once a single, connected system but were artificially separated in 1952 to prevent siltation from the Mfolozi River catchment which risked shallowing...