Youth Marker 0

In recent years, the spread of conservation agriculture (CA) has revealed to be a sustainable way to intensify crop production and sustain rural livelihoods in several African countries. Indeed, the potential benefits associated with the use of conservation farming practices are many. Long-term yield increase and output stability can be achieved while at the same time stopping and reversing land degradation. Larger outputs are often obtained by employing relatively fewer inputs, thereby reducing costs. Compared to conventional tillage methods, CA thus leads to higher net profitability, greater environmental sustainability and – especially important in Africa – higher food security. Furthermore, conservation farming techniques which rationalize the use of labour are particularly helpful in those rural areas where migration and health emergencies have reduced the labour supply and contributed to the increasing “feminization” of the agricultural sector (a comprehensive discussion of the advantages and disadvantages associated with the use of conservation agriculture in Africa is provided in Annex I).

In many sub-Saharan African (SSA) countries, poverty productivity which accelerating climate change and (Devereux and Edwards, 2004; Slingo et al., 2005). It is estimated that about 75% of the population of sub-Saharan Africa lives in arid and semi-arid areas that cover about 75% of sub-Saharan Africa. These areas are characterized by low soil chemical fertility and low annual rainfall that is poorly distributed (Maitima et al., 2009; Mubaya et al., 2010; Mugabe, 2011). Under this situation agricultural productivity by small scale farmers is very low resulting both in food and income insecurity leading to poverty (Majule, 2010).

Namibia is an arid country. 22 per cent of Namibia can be classified as desert, having a mean annual rainfall of less than 100 mm, 33 per cent classified as arid, with a mean annual rainfall of between 100 and 300 mm, 37 per cent classified as semi-arid, with a mean annual rainfall of between 301 and 500 mm, and 8 per cent as sub-humid, with a mean annual rainfall of between 501 and 700 mm. Associated with these low rainfall figures are high evapotranspiration rates and a high degree of variation from year to year, including a few years of exceptionally high and low rainfall, as well as variable rainfall distribution patterns within a year. Human endeavour must adapt to this reality.

Agriculture is the predominant land use in Namibia, where some 70% of the population depends directly or indirectly on the natural rangeland resource for their economic well-being and food security. Beef production is the most important livestock-related activity in Namibia, followed by small stock (sheep and goat) production. Since 1990, the Namibian commercial livestock sector has accounted for almost 70% of the overall annual agricultural output value. This activity is almost completely dependent on the country’s natural rangelands.

The Namibia Agriculture Policy is aimed at contributing to increased agricultural production, agro-processing and marketing as well as to serve as an overarching policy in the agricultural sector. The revised Policy Framework draws from Vision 2030, the fourth National Development Plan, the 2014 SWAPO Party Elections Manifesto and MAWF’s mandate. The Policy is formulated within the confines of the Namibian Constitution and will provide a framework for adjusting relevant laws to give effect to the stated policy objectives and strategies.

Water is the main factor affecting crop production in sub-Saharan Africa. It was hypothesized that intercropping sorghum (S) with either cowpea (C) or bottle gourd (B) would result in better productivity and water use efficiency (WUE). This was evaluated using a split-plot design with sub-plots arranged in a randomised complete block manner within the main plot, replicated thrice. Water regimes [full irrigation (FI), deficit irrigation (DI) and rainfed (RF)] were allocated to the main plots. Sub-plots comprised intercrop combinations, SS (sole), C (sole), B (sole), SC (intercrop) and SB (intercrop). Data collected included soil water content (SWC), plant height (PH)/vine length, leaf number (LN), tillering (T)/branching, leaf area index (LAI), relative leaf water content (RWC), stomatal conductance (gs) and chlorophyll content index (CCI) as well as biomass accumulation and partitioning. Yield and yield components, water use (WU) and WUE for grain (WUEg) were calculated at harvest. Land equivalent ratio (LER) was used to evaluate productivity of the intercrop. Sorghum canopy size decreased (P < 0.05) (−6.7%, −10.6%, −89% and −79% for PH, LN, T and LAI, respectively) with decreasing water availability. Sorghum growth and development were unaffected by intercropping. Intercropping sorghum with cowpea improved gs (23%) and CCI (6.56%) of sorghum under low water availability. Productivity of sorghum across varying water regimes and cropping systems was stable with final biomass, yield and harvest index of 2.4 t ha−1, 0.98 t ha−1 and 35%, respectively. Overall, LER showed a 46% increase in productivity across all intercrop systems. Intercropping marginally increased WU (5.64%). Improvements of WUEg were observed under SC and SB (54.65% and 46.98%, respectively) relative to SS. Intercropping sorghum with cowpea is recommended for semi-and arid environments since it promoted efficient use of water.

Farmers who still cultivate bambara groundnut (Vigna subterranea) rely on landraces and seed retained from previous harvests. Given that the crop is typically cultivated in semi-arid regions, seed quality of farmers’ retained seed might be compromised due to water stress experienced by maternal plants during production. The aim of this study was to determine the effect of water stress on maternal plants on subsequent seed quality of bambara groundnut. A single bambara groundnut landrace was characterised into four distinct selections based on seed coat and speckling colour. Initial seed quality (viability and vigour) was evaluated prior to planting seed in a field trial under irrigated and rainfed conditions. Final yield and yield components were determined at harvest. Thereafter, seed quality (viability and vigour) of progeny of different landrace selections was evaluated. Yield was lower under rainfed than irrigated conditions. Overall, subsequent seed quality showed improvement from initial seed quality of the original seedlot. Seed viability was higher in seeds produced under irrigated than rainfed conditions. Seed quality of bambara groundnut may be reduced underwater-limited production conditions. Seed enhancement practices such as priming may assist farmers to achieve better emergence. In the long term, seed production should be done under optimum conditions in order to achieve high-seed quality.

Climate Smart Agriculture (CSA) is crop and livestock production that sustainably increases productivity, resilience (adaptation), reduces/removes greenhouse gases (mitigation), and enhances achievement of national food security and development goals. CSA encourages the use of all available and applicable climate change solutions in a pragmatic and impact-focused manner. The Food Agriculture and Natural Resources Policy Analysis Network (FANRPAN) commissioned this scoping study on CSA with the overall objective of creating a policy environment that increase agricultural productivity and strengthen the resilience of vulnerable smallholder farmers to the impacts of climate change.

Three sweet potato cultivars (A40, A45 and 199062.1) were planted in three small-scale farms located under different agro-ecological zones of KwaZulu-Natal. The objective was to assess growth, physiological responses and yield of the sweet potato cultivars under low-input agricultural system and different environmental conditions. Sweet potato planted at Richards Bay (28°19'S; 32°06E), a coastal sandy soil location, recorded low stomatal conductance(SC; 102.2 m moles m−2 s−1) and chlorophyll content index (CCI; 29.4). This consequently resulted in reduced vine length, leaf number and branching of sweet potato plants. Environmental conditions in that location (Richards Bay) such as high evapotranspiration, high temperatures and low water retention capacity of sandy soils created drought stress condition. This caused reduction in photosynthetic activities and translocation to the harvestable plant parts. The other two locations (Deepdale at 28°01'S; 28°99'E and Umbumbulu at 29°98'S; 30°70'E) located further from the coast and characterized by clayey soils recorded higher SC and CCI. Branching and number of leaves were significantly influenced by locations and growing season while vine length varied with locations, indicating specific varietal adaptation. Biomass and storage root yield followed a similar trend as plant growth and physiology. Richards Bay recorded very low biomass and storage root yield (5.4 and 5.0 t ha−1) in both seasons while Deepdale recorded higher yields (42.0 t ha−1) during the first growing season. Yields reduced by 67% (13.6 t ha−1) in the second season. Storage root yields from Umbumbulu were stable in both growing seasons (29.4 and 28 t ha−1 during seasons one and two, respectively). Adding fertilizer only improved storage roots yield in Richards Bay, otherwise cultural practises were responsible for storage root yield increases in Deepdale and Umbumbulu. Orange-fleshed sweet potato cultivar A45 showed good environmental plasticity while cultivar 199062.1 responded well to fertilizer application. This indicated its suitability for use in food security programmes under low-input agriculture.

Amaranthus cruentus, Corchorus olitorius and Vigna unguiculata are traditional leafy vegetables with potential to improve nutritional security of vulnerable people. The promotion of these crops is partly hindered by the lack of agronomic information. The effect of plant spacing on growth, physiology and yield of these three leafy vegetables was evaluated under commercial-scale production at Roodeplaat, Pretoria over two summer seasons, 2011/12 and 2012/13. A randomised complete block design was used with plant density (100 000, 66 666 and 50 000 plants ha−1) as a factor. Chlorophyll content index (CCI), chlorophyll fluorescence, stomatal conductance, leaf number, leaf area index (LAI) and biomass were measured in situ. Planting at 100 000 plants ha−1 resulted in lower (P < 0.05) LAI, CCI and biomass per plant for A. cruentus and C. olitorius. Total yield of A. cruentus, C. olitorius andV. unguiculata was higher (P < 0.05) at 100 000 plants ha−1 relative to 50 000 and 66 666 plants ha−1. For A. cruentus and C. olitorius, higher leaf attributes (CCI, plant height, leaf number, biomass per plant and LAI) were obtained and this indicated that traditional leafy vegetables can be produced commercially under lower densities using a drip irrigation system. Using 66 666 plants ha−1 is suitable for commercial production of A. cruentus and C. olitorius, whereas 50 000 plants ha−1 may be recommended under low water availability. For V. unguiculata 100 000 plants ha−1 is recommended.