Quantifying productivity and water use of sorghum intercrop systems.

Ph. D. University of KwaZulu-Natal, Pietermaritzburg 2015.Rural sub-Saharan Africa (SSA) faces the challenge of achieving food security under water scarcity amplified by climate change and variability. Under these conditions, it is necessary to adopt cropping systems that have a potential to improve productivity. The aim of the study was to assess the feasibility of a sorghum-cowpea-bottle gourd intercrop systems with a view to determine the resource use efficiencies. This was achieved through a series of studies which included conducting critical literature reviews, quantifying water use and water use efficiency of sorghum-cowpea-bottle gourd, and modelling such systems using Agricultural Production Systems Simulator (APSIM). Field trials were conducted at the University of KwaZulu–Natal’s, Ukulinga Research Farm over two seasons (2013/14 and 2014/15) under varying water regimes [full irrigation (FI), deficit irrigation (DI) and rainfed (RF)]. Intercrop combinations considered were sole sorghum, cowpea and bottle gourd as well as intercrops of sorghum–cowpea and sorghum–bottle gourd. Data collected included soil water content, plant height/vine length, leaf number, tillering/branching, leaf area index, relative leaf water content, stomatal conductance and chlorophyll content index as well as biomass accumulation and partitioning. Yield and yield components, water use (WU) and WUE were calculated at harvest. Extinction coefficient, intercepted photosynthetic active radiation (IPAR) and radiation use efficiency (RUE) for biomass and grain were also determined. Land equivalent ratio (LER) was used to evaluate intercrop productivity. Growth, yield and water use (ET) of the sorghum–cowpea intercrop system were simulated using APSIM. The validated model was then used to develop best management practices for intercropping. The review showed that aboveground interactions within intercrop systems have thoroughly been investigated while belowground interactions were mostly limited. The review showcased the potential of bottle gourd as a versatile food crop. The field trials established that sorghum yields were stable across different water regimes. This was mainly achieved through facilitative interaction within the intercrop systems which allowed for greater eco-physiological adaptation resulting in improved water capture and use. Improved water capture and use also increased WUE (50.68%) and RUE (8.96%). The APSIM model was simulated growth, yield and WU of an intercrop system under varying water regimes satisfactorily. The model over–estimated biomass (6.25%), yield (14.93%) and WU (7.29%) and under–estimated WUE (-14.86%). Scenario analyses using APSIM showed that the development of best management practices should be agro–ecology specific to ensure dynamic climate change adaptation strategies and increase resilience. It was concluded that intercropping results in improved productivity, especially under water–limited conditions. As such, it that can be used by farmers located in semi-arid and arid regions as an adaptation strategy for increased productivity. Dynamic agronomic management practices should be adapted to further increase the system’s resilience to predicted climatic uncertainties. Future studies on intercropping should consider root interactions and possibly different plant populations and planting geometry as factors that might influence resource capture and use. Decision support systems should be promoted within farming communities to better manage risks associated with on-farm decision making

El Niño’s Effects on Southern African Agriculture in 2023/24 and Anticipatory Action Strategies to Reduce the Impacts in Zimbabwe

The frequency of El Niño occurrences in southern Africa surpasses the norm, resulting in erratic weather patterns that significantly impact food security, particularly in Zimbabwe. The effects of these weather patterns posit that El Niño occurrences have contributed to the diminished maize yields. The objective is to give guidelines to policymakers, researchers, and agricultural stakeholders for taking proactive actions to address the immediate and lasting impacts of El Niño and enhance the resilience of the agricultural industry. This brief paper provides prospective strategies for farmers to anticipate and counteract the El Niño-influenced dry season projected for 2023/24 and beyond. The coefficient of determination R2 between yield and ENSO was low; 11 of the 13 El Niño seasons had a negative detrended yield anomaly, indicating the strong association between El Nino’s effects and the reduced maize yields in Zimbabwe. The R2 between the Oceanic Nino Index (ONI) and rainfall (43%) and between rainfall and yield (39%) indirectly affects the association between ONI and yield. To safeguard farmers’ livelihoods and improve their preparedness for droughts in future agricultural seasons, this paper proposes a set of strategic, tactical, and operational decision-making guidelines that the agriculture industry should follow. The importance of equipping farmers with weather and climate information and guidance on drought and heat stress was underscored, encompassing strategies such as planting resilient crop varieties, choosing resilient livestock, and implementing adequate fire safety measures

Towards agroecological living landscapes: First experiences from CIMMYT-Zimbabwe

In Zimbabwe farm inputs are very expensive and climate change impacts are severe. The CGIAR initiative Transformational Agroecology across Food, Land, and Water Systems will build on the agroecological policy framework already in place and on several projects currently promoting agroecological principles. With coordination provided by the International Maize and Wheat Improvement Center (CIMMYT), the initiative will help build agroecological living landscapes in two territories with contrasting conditions and landscapes. In this video by the CIMMYT team, farmers and partners in these territories share their expectations about diversifying agricultural production through a mixed farming approach and about enhancing their capacity to adapt to climate change

Characteristics of maize growing farmers, varietal use and constraints to increase productivity in selected villages in the Eastern Cape province of South Africa

The need to increase self-sufficiency of rural agricultural systems has been a centre of focus for many extension programs aimed at rural development and improved livelihoods. Numerous biotic, abiotic and socio-economic factors affect maize production for resource poor farmers in the Eastern Cape (EC), which is one of the poorest Provinces in South Africa. Focus group discussions and semi-structured questionnaires were used to identify farmer characteristics, and specific production constraints influencing maize productivity in Jixini and Mkhwezo villages, of O. R. Tambo District in the EC Province. Elderly farmers who are above 56 years dominated the studied farming communities. The predominant varieties used were local landraces (53%) followed by hybrids (31%) and improved open pollinated varieties (OPVs) (11%). Farmers preferred local landraces as they were considered more palatable. Unmarried farmers were the least productive farmer group due to shortages of labour, use of landrace varieties and inadequate fertilizer. The main production constraints faced by farmers, were too much rain, pests and diseases infestation, drought stress due to climate change, and lack of fencing of the out-fields. Increasing the involvement of youths in agricultural activities could improve maize productivity. Maize breeding programs should solicit information on farmer-preferred traits and incorporate them into the improved varieties to enhance their desirability and adoption. Targeting of varieties should be guided by the most common constraints affecting maize productivity in a specific location rather than issuing blanket recommendations. Additionally, agricultural extension programs could improve their service delivery by having good knowledge of target-farmer traits, their farming practices and prevailing constraints. Information in this manuscript can go a long way in improving extension service delivery in the EC Province of the country

Management of soil fertility through application of fertilizers

This chapter presents technologies for replacing the nutrients lost from cropped fields with external fertilizer sources in a manner that minimizes the consequences of too little or too much application. The technology of using industrial fertilizers, organic fertilizers, and application of farmyard manure and compost alone or in combination with industrial fertilizers are discussed in detail

Can cereal-legume intercrop systems contribute to household nutrition in semi-arid environments: A systematic review and meta-analysis

Introduction: Intercropping cereals with legumes can intensify rainfed cereal monocropping for improved household food and nutritional security. However, there is scant literature confirming the associated nutritional benefits. Methodology: A systematic review and meta-analysis of nutritional water productivity (NWP) and nutrient contribution (NC) of selected cereal-legume intercrop systems was conducted through literature searches in Scopus, Web of Science and ScienceDirect databases. After the assessment, only nine articles written in English that were field experiments comprising grain cereal and legume intercrop systems were retained. Using the R statistical software (version 3.6.0), paired t-tests were used to determine if differences existed between the intercrop system and the corresponding cereal monocrop for yield (Y), water productivity (WP), NC, and NWP. Results: The intercropped cereal or legume yield was 10 to 35% lower than that for the corresponding monocrop system. In most instances, intercropping cereals with legumes improved NY, NWP, and NC due to their added nutrients. Substantial improvements were observed for calcium (Ca), where NY, NWP, and NC improved by 658, 82, and 256%, respectively. Discussion: Results showed that cereal-legume intercrop systems could improve nutrient yield in water-limited environments. Promoting cereal- legume intercrops that feature nutrient-dense legume component crops could contribute toward addressing the SDGs of Zero Hunger (SDG 3), Good Health and Well-3 (SDG 2) and Responsible consumption and production (SDG 12)

Table_2_Can cereal-legume intercrop systems contribute to household nutrition in semi-arid environments: A systematic review and meta-analysis.docx

IntroductionIntercropping cereals with legumes can intensify rainfed cereal monocropping for improved household food and nutritional security. However, there is scant literature confirming the associated nutritional benefits.MethodologyA systematic review and meta-analysis of nutritional water productivity (NWP) and nutrient contribution (NC) of selected cereal-legume intercrop systems was conducted through literature searches in Scopus, Web of Science and ScienceDirect databases. After the assessment, only nine articles written in English that were field experiments comprising grain cereal and legume intercrop systems were retained. Using the R statistical software (version 3.6.0), paired t-tests were used to determine if differences existed between the intercrop system and the corresponding cereal monocrop for yield (Y), water productivity (WP), NC, and NWP.ResultsThe intercropped cereal or legume yield was 10 to 35% lower than that for the corresponding monocrop system. In most instances, intercropping cereals with legumes improved NY, NWP, and NC due to their added nutrients. Substantial improvements were observed for calcium (Ca), where NY, NWP, and NC improved by 658, 82, and 256%, respectively.DiscussionResults showed that cereal-legume intercrop systems could improve nutrient yield in water-limited environments. Promoting cereal- legume intercrops that feature nutrient-dense legume component crops could contribute toward addressing the SDGs of Zero Hunger (SDG 3), Good Health and Well-3 (SDG 2) and Responsible consumption and production (SDG 12).</p

Table_1_Can cereal-legume intercrop systems contribute to household nutrition in semi-arid environments: A systematic review and meta-analysis.docx

IntroductionIntercropping cereals with legumes can intensify rainfed cereal monocropping for improved household food and nutritional security. However, there is scant literature confirming the associated nutritional benefits.MethodologyA systematic review and meta-analysis of nutritional water productivity (NWP) and nutrient contribution (NC) of selected cereal-legume intercrop systems was conducted through literature searches in Scopus, Web of Science and ScienceDirect databases. After the assessment, only nine articles written in English that were field experiments comprising grain cereal and legume intercrop systems were retained. Using the R statistical software (version 3.6.0), paired t-tests were used to determine if differences existed between the intercrop system and the corresponding cereal monocrop for yield (Y), water productivity (WP), NC, and NWP.ResultsThe intercropped cereal or legume yield was 10 to 35% lower than that for the corresponding monocrop system. In most instances, intercropping cereals with legumes improved NY, NWP, and NC due to their added nutrients. Substantial improvements were observed for calcium (Ca), where NY, NWP, and NC improved by 658, 82, and 256%, respectively.DiscussionResults showed that cereal-legume intercrop systems could improve nutrient yield in water-limited environments. Promoting cereal- legume intercrops that feature nutrient-dense legume component crops could contribute toward addressing the SDGs of Zero Hunger (SDG 3), Good Health and Well-3 (SDG 2) and Responsible consumption and production (SDG 12).</p