National Research Institutions

Bambara groundnut (Vigna subterranea (L.) Verdc.) is an underutilised species with potential to contribute nutritional and food security in marginal areas. Growth, phenology and yield of a local bambara groundnut landrace from Jozini, KwaZulu-Natal, characterised into three selections according to seed coat colour, namely Brown, Red and Light Brown, were evaluated under irrigated and rain-fed field conditions at Roodeplaat, Pretoria, over two seasons (2010/11 and 2011/12). Trials with three replicates were planted under rain-fed and irrigated conditions with seed colour as a subfactor. Emergence (up to 35 d after planting), plant height, leaf number, leaf area index, chlorophyll content index and stomatal conductance were measured in situ. Yield and components of yield were determined at harvest. The Red, Brown and Light Brown landrace selections emerged well (84%, 81% and 51%, respectively). Plant physiological and growth parameters of stomatal conductance, chlorophyll content index, plant height, leaf number, leaf area index and biomass accumulation were lower under rain-fed relative to irrigated conditions. Adaptations were landrace selection-specific, with the Brown and Red landrace selections showing better adaptation to rain-fed conditions. Under rain-fed conditions, bambara groundnut landrace selections flowered, senesced and matured earlier relative to irrigated conditions. Consequently, there were lower yields under rain-fed compared with irrigated conditions. The Red and Brown landrace selections may have drought-avoidance mechanisms. Seed colour may be used as a selection criterion for drought tolerance in bambara groundnut landraces.

The 2013 AAEA & CAES Joint Annual Meeting in Washington, DC will offer AAEA members, CAES members, and other applied economists a chance to interact and learn over the course of the three day meeting on August 4-6. This year’s meeting features a large amount of educational content including:

More than 150 educational sessions

Over 200 posters on display, with opportunities to interact with their authors

Multiple plenary sessions each day, featuring high-profile speakers

Common research topics include:

International development

Climate change

Biofuels

Linkages between food and health

The Farm Bill

Land use and water resource issues

Regional economics

Business economics

Behavioral economics

The meeting will also feature a number of chances for attendees to connect and network at the welcome and closing receptions, receptions for specific Sections of AAEA, and evening gatherings organized by universities and government agencies.

Agriculture in Namibia plays a critical role in the formal and informal economy supporting 70% of the population directly or indirectly through employment and income generation. The agricultural sector in Namibia contributes over 10% to the GDP of which 75-80% can be attributed to livestock farming. The livestock industry accounts for 90% of all agricultural production in Namibia with approximately 60% of households owning cattle, including nearly 40% of poor households. Crop production activities in Namibia are limited, mainly due to the arid climate and low rainfall patterns. Rain-fed crops include pearl millet, sorghum and maize are the most dominant crops grown in Namibia. The average yield for these crops ranges from 24.7 ton for pearl millet, 72,438 for maize and 14,819 for wheat. The dependence on rain-fed agriculture increases the vulnerability of farming systems and predisposes rural households to food insecurity and poverty. However, the reduction in crop yields will have devastating impacts on food security at both national and household levels. Under the current conditions, the agriculture sector in Namibia needs to grow by 4% a year to meet the food requirements for the expanding population. In light of these challenges, Namibia needs to adapt its agricultural practices and increase the resilience of livelihoods to be able to withstand the challenges posed by climate change to sustain development and growth of the country.

Scientific trials on farms on Namibia-specific Conservation Agriculture or Tillage (NSCA) over the last ten years have been revolutionising rain fed grain crop yields to the extent that Namibia could become self sufficient in millet and maize production in the not too distant future despite the effects of climate change.

This is the expert opinion of independent consultant and acknowledged conservation agriculturalist beyond Namibian borders, Rod Davis. “Far from our crop production being liable to drop by 50% because of climate change according to the ‘experts’, we are presently seeing millet yields increasing from the national average of 300 kilogrammes per hectare to 3000 kilogrammes and more even during the current severe drought. Would interested and affected parties, including ministries, please take note. (CA) Conservation Agriculture practises, such as no-till, that work in other countries don’t work here because of our low and erratic rainfall and degraded soils,” says Davis.

He adds that Conservation Tillage (CT) is specifically designed for Namibian conditions and it really works and its benefits extend to soil degradation reversal; farmer livelihood improvement; food security; combating deforestation and labour saving per unit of yield, the list goes on. The system employs, as part of the package, Namibian unique Ripper Furrowing (RF) tillage technology. RF is a combined operation where the implement rips 30 centimtres deep, shattering the hard pan caused mainly by the compacting effect of disc harrowing, whilst at the same time forming water harvesting furrows. The rip line is at the base of the furrow where the crop is planted while the furrow sides deliver 75% more moisture to the crop. Crop rotation with legumes is also part of the system with indigenous cowpea, bambara nut and ground nut which are all highly nutritious as well as marketable.

“To us and also to the rapidly growing number of CT/CA farmers, to whom we have introduced the system, there is no need to spend any more time dithering and wondering what to do next! The system definitely works really very well whether small or large scale.

However; some problems need to be addressed, as follows:

RF alone, without the rest of the package, will not improve the soil. Yields will increase initially with deeper rooting finding leached nutrients plus the additional moisture. Therefore, in the medium term yields are likely to drop back meaning farmers will become disillusioned,

Presently there are no less than ten Namibian based organisations involved in CT/CA, six directly and four indirectly with some variances in approach and methodology. To ensure that farmers are basically told the same thing by these initiatives, a more associative approach between these organisations for better harmonised introduction and adoption should be considered. This would hopefully also assist in more collaboration and less competition as at present,CT/CA should be regarded as a continuum with changes made when needed and recognised, and of course agreed upon. For example Conservation Agriculture Namibia (C.A.N.) have introduced what is called the 2,2,2, crop rotation system where two rows of a grain crop next to two rows legume and two rows grain crop are planted (grains are either indigenous mahangu or short season drought resistant maize). This works well in that nitrification by the legume adjoining the mahangu or maize is quicker.

On the farmers’ side, the most important element is, as always, management. This is the golden rule for the extraordinary high yields being achieved.

A brief overview of adaptation options and measurements

No information is available on responses of South African taro landraces to water stress. The objective of this study was to evaluate the responses, and mechanisms thereof, of taro to water stress under controlled and field conditions. Taro landraces were collected from rural areas in KwaZulu-Natal, South Africa. A pot trial was planted in tunnels at the University of KwaZulu-Natal with two factors: three landraces and water stress (NS – no stress, IS – intermittent stress and TS – terminal stress), replicated six times. For NS, soil water content (SWC) was maintained at 75% field capacity (FC). IS involved watering pots to 75% FC during crop establishment, and allowing SWC to deplete to 30% FC during the vegetative stage, before returning to 75% until harvest maturity. For TS, SWC was maintained at 30% FC for the entire growing period. Field trials were planted in October 2010, with irrigation (full irrigation versus rainfed) as a main factor and landrace type as sub-factor, replicated three times. SWC was monitored weekly. Emergence, plant height, leaf number, leaf area, LAI, vegetative growth index (VGI) and stomatal conductance (SC) were determined weekly. Results from both pot and field trials showed that taro landraces were slow to emerge (~49 days). There were significant differences (P<0.001) between landraces with respect to final emergence. Taro growth (plant height, leaf number and leaf area), for both trials, was shown to be significantly (P<0.05) reduced by water stress. Under field conditions, SC, LAI and VGI were significantly (P<0.05) lower under rainfed conditions compared with irrigated conditions. It is concluded that emergence and vegetative growth parameters of KwaZulu-Natal taro landraces are sensitive to water stress. Data from this study will be used to calibrate AquaCrop and presented as a possible option to manage taro under dryland and irrigated conditions in the warm subtropical areas of South Africa.

Historically, traditional cropping systems are based on diversification, thus making a significant contribution to food security for the household. Intercropping may offer farmers the opportunity to mimic this diversity. The aim of this study was to evaluate the productivity of a taro-bambara intercrop. The intercrop combinations were 1:1 and 1:2, compared with taro and bambara sole crops. Growth parameters and yield components were determined separately for each crop. Thereafter, land equivalent ratio (LER) was calculated to evaluate the productivity of the intercrop. Plant height of taro, as the main crop, was not significantly affected by intercropping. However, leaf number was significantly affected (P<0.001). Intercropping taro resulted in reduced leaf number compared with the sole crop; leaf number in response to the 1:2 intercrop was significantly lower than that of 1:1 intercrop. Bambara growth was significantly (P<0.05) affected by intercropping in that plants were taller and had more leaves when intercropped with taro. Taro yield was not significantly affected by intercropping, although yield generally decreased under intercropping compared with the sole crop. Bambara yield was also not significantly affected by intercropping. The LER showed that intercropping was more productive than sole cropping. The 1:1 intercrop had a LER of 1.71 compared with 1.36 for the 1:2 intercrop. It is concluded that although intercropping had variable effects on the growth of both taro and bambara, there was an agronomic advantage to intercropping.

The CCARDESA Secretariat wishes to invite applications from qualified and competent candidates who are nationals of the SADC member countries to fill the position of Internal Auditor.

The main aim of the Conference was to have a dialogue on matters relating to climate change as it affects agriculture in Southern Africa, to share lessons and progress made. The first part of the conference dealt with presentations from a number of countries in Southern Africa on their experiences and coping mechanisms, and this was followed by a session primarily dedicated to South African experiences.

This report presents the proceedings of the Climate Proofing and CSA Training in Cape Town in October 2016.