From adoption claims to understanding farmers and contexts: A literature review of Conservation Agriculture (CA) adoption among smallholder farmers in southern Africa

Increasing adaptation to climate stress by applying conservation agriculture in Southern Africa.

10.1079/9781789245745.0016 ◽

2022 ◽

pp. 270-283

Author(s):

Christian Thierfelder ◽

Peter Steward

Keyword(s):

Climate Change ◽

Soil Moisture ◽

Heat Stress ◽

Drought Stress ◽

Southern Africa ◽

Smallholder Farmers ◽

Conservation Agriculture ◽

Crop Productivity ◽

Soil Disturbance ◽

On Farm

Abstract Climate change and soil fertility decline are threatening food security in southern Africa and efforts have been made to adapt current cropping systems to the needs of smallholder farmers. Conservation Agriculture (CA) based on minimum soil disturbance, crop residue retention and crop diversification has been proposed as a strategy to address the challenges smallholder farmers face. Here we analyse the potential contributions of CA towards adaptation to the effects of climate change by summarizing data on infiltration, soil moisture dynamics and crop productivity under heat and drought stress. The data were taken in the main from CIMMYT's on-farm and on-station trial network. Data show that CA systems maintain 0.7-7.9 times higher water infiltration than the conventional tilled system depending on soil type, which increases soil moisture during the cropping season by 11%-31% between CA treatments and the conventional control treatment. This leads to greater adaptive capacity of CA systems during in-season dry spells and under heat stress. A supporting regional maize productivity assessment, analysing the results of numerous on-farm and on-station experiments, showed that CA systems will outperform conventional tillage practices (CP), especially on light-textured soils, under heat and drought stress. With higher rainfall and low heat stress, this relation was more positive towards CP and on clay soil there was no benefit of practising CA when rainfall was high. The long dry season and limited biomass production of CA systems in southern Africa require complementary good agricultural practices to increase other soil quality parameters (e.g. increased soil carbon) to maintain higher productivity and sustainability over time. This can be addressed by combinations of improved stress-tolerant seed, targeted fertilization, inclusion of tree-based components or green manure cover crops in the farming system, scale-appropriate mechanization and improved weed control strategies.

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The impact of adoption of conservation agriculture on smallholder farmers’ food security in semi-arid zones of southern Africa

Agriculture & Food Security ◽

10.1186/s40066-017-0109-5 ◽

2017 ◽

Vol 6 (1) ◽

Cited By ~ 18

Author(s):

Nelson Mango ◽

Shephard Siziba ◽

Clifton Makate

Keyword(s):

Food Security ◽

Southern Africa ◽

Smallholder Farmers ◽

Conservation Agriculture ◽

Arid Zones ◽

The Impact ◽

Semi Arid

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Enhancing climate resilience using stress-tolerant maize in conservation agriculture in southern Africa.

10.1079/9781789245745.0013 ◽

2022 ◽

pp. 230-245

Author(s):

Peter Setimela ◽

Isaiah Nyagumbo ◽

Walter Mupangwa ◽

Munyaradzi Mutenje

Keyword(s):

Southern Africa ◽

Smallholder Farmers ◽

Conservation Agriculture ◽

Growing Season ◽

Economic Benefits ◽

Maize Germplasm ◽

Maize Cultivars ◽

Climate Resilience ◽

Drought Tolerant ◽

Smart Agriculture

Abstract Recurrent and widespread droughts in southern Africa (SA) reduce agricultural productivity and increase food insecurity among smallholder farmers. The average growing-season temperatures are expected to increase by 2.5°C. In SA maize is a staple food, accounting for more than 30% of total calories. The crop is mostly grown by smallholder farmers with limited inputs of fertilizers and improved seed. Most of the maize cultivars grown by farmers are susceptible to heat and drought. Multi-stress-tolerant maize germplasm is one of the climate smart agriculture (CSA) components and, when used in combination with others, can sustainably increase production and resilience of agricultural systems. In this paper we review the performance and economic benefits of drought-tolerant maize cultivars under conventional monocropping practice, under conventional intercropping and in Conservation Agriculture (CA) as part of sustainable intensification to ensure food security for smallholder farmers.

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The crucial role of mulch to enhance the stability and resilience of cropping systems in southern Africa

Agronomy for Sustainable Development ◽

10.1007/s13593-021-00687-y ◽

2021 ◽

Vol 41 (2) ◽

Author(s):

Blessing Mhlanga ◽

Laura Ercoli ◽

Elisa Pellegrino ◽

Andrea Onofri ◽

Christian Thierfelder

Keyword(s):

Crop Rotation ◽

Southern Africa ◽

Cropping Systems ◽

Conservation Agriculture ◽

Conventional Tillage ◽

Yield Stability ◽

No Tillage ◽

The Stability ◽

Stability And Resilience

AbstractConservation agriculture has been promoted to sustainably intensify food production in smallholder farming systems in southern Africa. However, farmers have rarely fully implemented all its components, resulting in different combinations of no-tillage, crop rotation, and permanent soil cover being practiced, thus resulting in variable yield responses depending on climatic and soil conditions. Therefore, it is crucial to assess the effect of conservation agriculture components on yield stability. We hypothesized that the use of all three conservation agriculture components would perform the best, resulting in more stable production in all environments. We evaluated at, eight trial locations across southern Africa, how partial and full implementation of these components affected crop yield and yield stability compared with conventional tillage alone or combined with mulching and/or crop rotation. Grain yield and shoot biomass of maize and cowpea were recorded along with precipitation for 2 to 5 years. Across different environments, the addition of crop rotation and mulch to no-tillage increased maize grain by 6%, and the same practices added to conventional tillage led to 13% yield increase. Conversely, adding only mulch or crop rotation to no-tillage or conventional tillage led to lower or equal maize yield. Stability analyses based on Shukla’s index showed for the first time that the most stable systems are those in which mulch is added without crop rotation. Moreover, the highest yielding systems were the least stable. Finally, additive main effects and multiplicative interaction analysis allowed clarifying that mulch added to no-tillage gives stable yields on sandy soil with high rainfall. Similarly, mulch added to conventional tillage gives stable yield on sandy soil, but under low rainfall. This is the first study that highlighted the crucial role of mulch to enhance the stability and resilience of cropping systems in southern Africa, supporting their adaptability to climate change.

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