Periodic Reporting for period 1 - EcoDiv (An ecological framework to advance crop diversification in southern Africa)
Berichtszeitraum: 2023-03-06 bis 2025-06-05
Crop diversification is critical to sustainable agriculture, offering opportunities to utilise positive interactions between different crops to increase productivity and resilience, and minimise the need for economically and environmentally costly agricultural inputs. EcoDiv investigates how ‘option by context’ interaction determines the contribution of crop diversification to food security for smallholder farmers in southern Africa, with a focus on Zambia. EcoDiv has three research objectives:
(1) Quantify how the crop production differs among crop configuration options under different environmental conditions.
(2) Identify which crop configuration options can best meet different socioeconomic needs in different environments.
(3) Investigate whether differences in crop configuration performance are determined by their effects on and interactions within the field microhabitat (temperatures, moisture, soil organic matter and nitrogen, and weed, pest, and disease pressure).
In parallel to these research objectives, EcoDiv seeks to develop the career of the lead researcher, Chloe MacLaren, and to establish a collaborative relationship between the EU host, SLU’s Department of Crop Production Ecology, and the outgoing host, CIMMYT Zimbabwe.
EcoDiv collaborates with the larger project ‘Sustainable Intensification for Smallholder Farmers in Zambia’ (SIFAZ) led by CIMMYT, FAO and Zambia’s Ministry of Agriculture. EcoDiv’s societal impacts are realised through its contributions to future research, extension and policy activities undertaken by these organisations.
(1) Quantify how the crop production differs among crop configuration options under different environmental conditions.
(2) Identify which crop configuration options can best meet different socioeconomic needs in different environments.
(3) Investigate whether differences in crop configuration performance are determined by their effects on and interactions within the field microhabitat (temperatures, moisture, soil organic matter and nitrogen, and weed, pest, and disease pressure).
In parallel to these research objectives, EcoDiv seeks to develop the career of the lead researcher, Chloe MacLaren, and to establish a collaborative relationship between the EU host, SLU’s Department of Crop Production Ecology, and the outgoing host, CIMMYT Zimbabwe.
EcoDiv collaborates with the larger project ‘Sustainable Intensification for Smallholder Farmers in Zambia’ (SIFAZ) led by CIMMYT, FAO and Zambia’s Ministry of Agriculture. EcoDiv’s societal impacts are realised through its contributions to future research, extension and policy activities undertaken by these organisations.
EcoDiv is still underway: the outgoing phase (2 years in Zimbabwe) has recently been completed, with the return phase remaining (1 year in Sweden). All necessary data has been shared by CIMMYT or collected by the researcher and her postgraduate students from on-farm trials in Zambia. Some data analyses have been completed and several scientific publications are in the pipeline. Results so far have been presented at two conferences (the World Congress of Conservation Agriculture, and the European Society of Agronomy Congress, both in 2024).
EcoDiv’s results so far suggest that:
1) Maize and legume crops have contrasting responses to different crop configurations along the rainfall gradient from southern to eastern Zambia: legumes perform better in intercrops and strip crops in drier conditions, while maize performs better in these configurations in wetter conditions. However, along the rainfall gradient, the two crops compensate for one another in each configuration, leading to a consistent land equivalence ratio of intercropping compared to crop rotation along the rainfall gradient.
2) Although rainfall affects the relative productivity of maize and legumes in different crop configurations, these changes are small, and rainfall does not affect the overall ranking from most to least productive treatment. Rotations consistently provide the highest relative yields of each individual crop per hectare, but strip crop and intercrop configurations always had the highest land use efficiency when considering the combined yield of both crops.
3) Rotations require more land than intercrops and strip crops, but intercrops and strip crops require more labour to achieve the same productivity. Rotations can thus offer a more suitable diversification option for labour-constrained farmers, while intercrops and strip crops would better suit land-constrained farmers.
1) Maize and legume crops have contrasting responses to different crop configurations along the rainfall gradient from southern to eastern Zambia: legumes perform better in intercrops and strip crops in drier conditions, while maize performs better in these configurations in wetter conditions. However, along the rainfall gradient, the two crops compensate for one another in each configuration, leading to a consistent land equivalence ratio of intercropping compared to crop rotation along the rainfall gradient.
2) Although rainfall affects the relative productivity of maize and legumes in different crop configurations, these changes are small, and rainfall does not affect the overall ranking from most to least productive treatment. Rotations consistently provide the highest relative yields of each individual crop per hectare, but strip crop and intercrop configurations always had the highest land use efficiency when considering the combined yield of both crops.
3) Rotations require more land than intercrops and strip crops, but intercrops and strip crops require more labour to achieve the same productivity. Rotations can thus offer a more suitable diversification option for labour-constrained farmers, while intercrops and strip crops would better suit land-constrained farmers.