Moeletsi M.E.,ARC Institute for Soil |
Mellaart E.A.R.,EcoLink |
Mpandeli N.S.,Private Bag X447 |
Hamandawana H.,ARC Institute for Soil
Journal of Agricultural Education and Extension | Year: 2013
Purpose: New innovative ways of communicating agrometeorological information are needed to help farmers, especially subsistence/small-scale farmers, to cope with the high climate variability experienced in most parts of southern Africa. Design/methodology/approach: The article introduces an early warning system for farmers. It utilizes short messaging system (SMS) to convey weather information and basic agronomic advice to 12 small-scale farmers in Makhado Municipality, Limpopo Province, South Africa. This case study demonstrates the usefulness of incorporating weather information on day-to-day farm management activities. Coded rainfall forecasts for light (0-5mm), medium (5-20mm) and heavy rainfall (>20mm) were distributed three times a week to individual farmers and extension officers. Accompanying the forecasts were possible agricultural activities for the week. Findings: Extensive training of the farmers and extension officers is a pre-requisite for full comprehension of the coded SMS early warning system. The recommendations on farming conditions are not always adhered to due to farmers' indigenous knowledge and other factors like access to labour. Practical implications: Weather and climate information distributed to farmers has the potential to add value to the farming methods employed, hence positively impacting on rural food security. Originality/value: The article demonstrates that agrometeorological information must be packaged in such a way as to assist farmers and should be disseminated timeously and appropriately to maximize its utility or adoption. © 2013 Copyright Wageningen University.
Adeleke R.,Rhodes University |
Adeleke R.,ARC Institute for Soil |
Dames J.F.,Rhodes University
South African Journal of Botany | Year: 2014
Truffles are generally known to form a mycorrhizal relationship with plants. Kalaharituber pfeilii (Hennings) Trappe & Kagan-Zur is a species of desert truffle that is found in the southern part of Africa. The life cycle of this truffle has not been fully investigated as there are many unconfirmed plant species that have been suggested as potential hosts. Many mycorrhizal associations often involve other role players such as associated bacteria that may influence the establishment of the mycorrhizal formation and function. As part of an effort to understand the life cycle of K. pfeilii, laboratory experiments were conducted to investigate the role of ascocarp associated bacteria. Bacterial isolates obtained from the truffle ascocarps were subjected to microbiological and biochemical tests to determine their potentials as mycorrhizal helper bacteria. Tests conducted included stimulation of mycelial growth in vitro, indole acetic acid (IAA) production and phosphate solubilising. A total of 17 bacterial strains belonging to the Proteobacteria, Firmicutes and Actinobacteria were isolated from the truffle ascocarps and identified with sequence homology and phylogenetic methods. Three of these isolates showed potential to be helper bacteria in at least one of the media tested through the stimulation of mycelial growth. Furthermore, four isolates produced IAA and one was able to solubilise CaHPO3 in vitro. One isolate, identified as a relative of Paenibacillus sp. stimulated mycelial growth on all the media tested. Other bacterial isolates that showed potential stimulation of mycelial growth were identified molecularly as a Bacillus sp. and two strains of Rhizobium sp. This study has contributed to the existing knowledge on the biotic interactions with K. pfeilii which may be useful in further symbiont and re-synthesis investigations. © 2013 South African Association of Botanists.
Van Jansen Rensburg H.G.,University of Pretoria |
Claassens A.S.,University of Pretoria |
Beukes D.J.,ARC Institute for Soil
South African Journal of Plant and Soil | Year: 2010
The interrelationships between elemental content of selected soil and leaf nutrients and maize grain yield were evaluated in a liming experiment conducted on a Hutton and Oakleaf soil in a resource-poor farming area in the Mpumalanga Province of South Africa. Improved uptake of Mo by maize with increased soil P status was found on the Hutton soil, while N and P uptake improved, due to lime and fertiliser application, on both soils. Boron uptake by maize was depressed with lime application on the Oakleaf soil. Maize yield on the Hutton soil was adversely affected by Al toxicity, while plant Ca deficiency was the dominant factor that limited maize grain yield, followed by Al level and a depressed B uptake on the Oakleaf soil. Nutrient vector analyses showed a toxic build-up of Fe, followed by Al and to a lesser extent Mn. These toxic elements depressed the uptake of Ca, Mg and B by maize on the Hutton soil. On the Oakleaf soil, Al toxicity, followed by high concentrations of Mn and Fe, markedly reduced the uptake of Ca, Mg and K by maize.
Beukes D.J.,ARC Institute for Soil |
Mapumulo T.C.,ARC Institute for Soil |
Fyfield T.P.,ARC Institute for Soil |
Jezile G.G.,ARC Institute for Soil
South African Journal of Plant and Soil | Year: 2012
A five-year study was conducted to assess the seasonal and medium-term effects of liming and fertilisation of an acid clay loam topsoil on soil properties and on the growth and yield of maize under dry land. Treatments consisted of a control, a once-off application of three levels of dolomitic lime, annual application of two levels of inorganic fertiliser, and three levels of chicken manure. A no-till practice was used with hand planting and fertiliser application. Leaf and soil sampling, as well as harvesting, were performed and analyses done. Soil extractable acidity, acid saturation and leaf Mn and K were reduced significantly, whereas soil pH, soil and leaf P, Ca and Mg increased significantly with an increase in lime application. Liming had no clear effect on soil K, maize leaf N, Cu, Fe and Zn, or on maize grain yield. The higher commercial fertiliser level significantly increased soil P, K and Ca, as well as leaf N, P, K, Cu, Mn and grain yield, compared to the traditional level. These results emphasise the longevity of liming application and that low soil fertility, followed by soil acidity, are the primary factors limiting soil productivity in the study area. Copyright © Combined Congress Continuing Committee.
Moeletsi M.E.,ARC Institute for Soil |
Moeletsi M.E.,University of Limpopo |
Tongwane M.I.,ARC Institute for Soil
Animals | Year: 2015
Manure management in livestock makes a significant contribution towards greenhouse gas emissions in the Agriculture; Forestry and Other Land Use category in South Africa. Methane and nitrous oxide emissions are prevalent in contrasting manure management systems; promoting anaerobic and aerobic conditions respectively. In this paper; both Tier 1 and modified Tier 2 approaches of the IPCC guidelines are utilized to estimate the emissions from South African livestock manure management. Activity data (animal population, animal weights, manure management systems, etc.) were sourced from various resources for estimation of both emissions factors and emissions of methane and nitrous oxide. The results show relatively high methane emissions factors from manure management for mature female dairy cattle (40.98 kg/year/animal), sows (25.23 kg/year/animal) and boars (25.23 kg/year/animal). Hence, contributions for pig farming and dairy cattle are the highest at 54.50 Gg and 32.01 Gg respectively, with total emissions of 134.97 Gg (3104 Gg CO2 Equivalent). Total nitrous oxide emissions are estimated at 7.10 Gg (2272 Gg CO2 Equivalent) and the three main contributors are commercial beef cattle; poultry and small-scale beef farming at 1.80 Gg; 1.72 Gg and 1.69 Gg respectively. Mitigation options from manure management must be taken with care due to divergent conducive requirements of methane and nitrous oxide emissions requirements. © 2015 by the authors; licensee MDPI, Basel, Switzerland.
van Rensburg L.D.,University of the Free State |
Botha J.J.,University of the Free State |
Botha J.J.,ARC Institute for Soil |
Anderson J.J.,University of the Free State |
Hensley M.,University of the Free State
Irrigation and Drainage | Year: 2012
Hensley et al. (2000) proposed an in-field rainwater harvesting (IRWH) technique for rural farmers located east of Bloemfontein South Africa, a semi-arid environment. This technique combines the advantages of water harvesting, no-till and basin tillage to stop ex-field runoff on high clay soils. The full agronomic potential of the IRWH technique has not, however, been reached because the main cause of water loss is evaporation. Evaporation dominates the hydrological cycle in semi-arid environments. This paper reviews the nature and design of the IRWH system, specifically the effect of mulch type on evaporation and yield. The effect of mulch type on yield is described by an infiltration ratio of the basin versus the runoff area over a period of three years. The function of the basin and catchment area is also discussed. The function of the basin area was to stop ex-field runoff completely, to maximize infiltration and to store the collected water in the soil layers beneath the evaporation sensitive zone. The catchment area was designed to promote in-field runoff and to act as a storage medium for water. Results from this research provide a new perspective on mulch management within water harvesting systems. © 2012 John Wiley & Sons, Ltd.
Moeletsi M.E.,ARC Institute for Soil |
Moeletsi M.E.,University of Limpopo |
Tongwane M.,ARC Institute for Soil |
Tsubo M.,ARC Institute for Soil
Advances in Meteorology | Year: 2016
The study investigated the cessation, onset, and duration of light, medium, and heavy frost in Free State province of South Africa using minimum temperatures from 1960 to 2015. Trends in the frost indices were assessed using the Man-Kendall test. Onset of frost varied spatially with earlier onset over the northern, eastern, and southeastern parts. Areas of early onset also experience late cessation of frost resulting in shorter growing period of less than 240 days. The western parts have longer growing period exceeding 240 days due to earlier cessation of frost and relatively late onset of frost. Trends for the frost-free period (growing period) show contrasting negative and positive trends with isolated significant trends. © 2016 Mokhele Edmond Moeletsi et al.
Van Huyssteen C.W.,University of the Free State |
Turner D.P.,ARC Institute for Soil |
Le Roux P.A.L.,University of the Free State
South African Journal of Plant and Soil | Year: 2013
Humans classify their environment to create order, make it understandable, aid recollection and to communicate. The nature of these classifications is not always understood, because they are learnt from an early age. Building on these principles provides a sound basis for any scientific classification. This paper explores these principles, those of the USDA Soil Taxonomy, the World Reference Base for soil resources, and the South African Soil Taxonomy. Knowledge should be ultimate aim of soil classification. A hierarchical system with four levels is proposed for the South African Soil Taxonomy. This can easily be achieved by adding a higher level, proposed to be called a Soil Group, to the current three levels (form, family, and phase). The South African Soil Taxonomy must guard against too many taxa, because humans have a limited ability to comprehend numerous taxa. The distinguishing criteria between taxa should be more clearly defined, while at the same time guarding against becoming too data hungry. The classification should not shy away from intergrades. The object being classified (soils) is a natural system and intergrades will necessarily occur. It is proposed that these should be classified as intergrades, rather than trying to artificially separate natural soil bodies. Copyright © Combined Congress Continuing Committee.
Hensley M.,University of the Free State |
Bennie A.T.P.,University of the Free State |
van Rensburg L.D.,University of the Free State |
Botha J.J.,ARC Institute for Soil
Water SA | Year: 2011
This review provides an overview of Water Research Commission (WRC)-funded research over the past 36 years. A total of 28 WRC reports have been consulted, 13 of these compiled by the University of the Free State, 4 by the University of Fort Hare, and the remainder mainly by the ARC-Institute for Soil Climate and Water. This work has resulted in extensive capacity building in this field - numerous technical assistants and 58 researchers have been involved, of which 23 are still active in research. The focus on the water flow processes in the soil-plant-atmosphere continuum (SPAC), with particular emphasis on processes in the soil, has greatly enhanced understanding of the system, thereby enabling the formulation of a quantitative model relating the water supply from a layered soil profile to water demand; the formulation of logical quantitative definitions for crop-ecotope specific upper and lower limits of available water; the identification of the harmful rootzone development effects of compacted layers in fine sandy soils caused by cultivation, and amelioration procedures to prevent these effects; and management strategies to combat excessive water losses by deep drainage. The explanation of the way in which SPAC is expressed in the landscape in the form of the ecotope has been beneficial with regard to the extrapolation of studies on particular SPACs to the large number of ecotopes where detailed studies have not been possible. Valuable results are reported regarding rainfall and runoff management strategies. Longer fallow periods and deficit irrigation on certain crop ecotopes improved rainfall use efficiency. On semi-arid ecotopes with high-drought-risk clay and duplex soils and high runoff losses, in-field rainwater harvesting (IRWH), designed specifically for subsistence farmers, resulted in maize and sunflower yield increases of between 30% and 50% compared to yields obtained with conventional tillage. An indication of the level of understanding of the relevant processes that has been achieved is demonstrated by their quantitative description in mathematical and empirical models: BEWAB for irrigation, SWAMP mainly for dryland cropping, and CYP-SA for IRWH. Five important related research and development needs are identified. The WRC has played, and continues to play, an important role in commissioning and funding research on water utilisation in agriculture and has clearly made an excellent contribution to the progress made in addressing the needs and requirements of subsistence, emergent and dryland farmers in South Africa.
PubMed | ARC Institute for Soil
Type: Journal Article | Journal: Animals : an open access journal from MDPI | Year: 2015
Manure management in livestock makes a significant contribution towards greenhouse gas emissions in the Agriculture; Forestry and Other Land Use category in South Africa. Methane and nitrous oxide emissions are prevalent in contrasting manure management systems; promoting anaerobic and aerobic conditions respectively. In this paper; both Tier 1 and modified Tier 2 approaches of the IPCC guidelines are utilized to estimate the emissions from South African livestock manure management. Activity data (animal population, animal weights, manure management systems, etc.) were sourced from various resources for estimation of both emissions factors and emissions of methane and nitrous oxide. The results show relatively high methane emissions factors from manure management for mature female dairy cattle (40.98 kg/year/animal), sows (25.23 kg/year/animal) and boars (25.23 kg/year/animal). Hence, contributions for pig farming and dairy cattle are the highest at 54.50 Gg and 32.01 Gg respectively, with total emissions of 134.97 Gg (3104 Gg CO Equivalent). Total nitrous oxide emissions are estimated at 7.10 Gg (2272 Gg CO Equivalent) and the three main contributors are commercial beef cattle; poultry and small-scale beef farming at 1.80 Gg; 1.72 Gg and 1.69 Gg respectively. Mitigation options from manure management must be taken with care due to divergent conducive requirements of methane and nitrous oxide emissions requirements.