The overall objective of this CRP is to pilot test soil management and agronomic practices in mulch-based farming systems that aim to restore soil fertility, optimize ecosystem service efficiency and increase agricultural productivity, while adapt to and mitigate the adverse effects of climate change and variability in cropping or integrated crop-livestock systems in the moist and dry savannahs of Sub-Saharan Africa (SSA). The goal is to improve the livelihoods of resource-poor farmers and rural communities in the region which is dominated by a savannah ecosystem in its natural state. The key to the management of soils in mulch-based farming systems is to increase the soil organic matter content (carbon sequestration) and to maximize the efficiency of utilization of soil nutrients, applied synthetic and organic fertilizers and water storage for crop growth. Soil organic matter plays a key role in soil fertility by providing plant nutrients, especially nitrogen, phosphorus and sulphur, stabilizing soil structure (aggregation, porosity) which in turn improves the capacity of the soil to absorb and hold water for crop growth, as well as providing a carbon source for the soil fauna and flora which themselves interact with and enhance the soil’s chemical and physical properties. The use of stable isotopic techniques (13C and 15N) at enriched or natural abundance levels will facilitate an in-depth analysis and understanding of the basic soil biological-physical processes, including soil C and nutrient cycling in mulch-based systems. The CRP will provide a platform for extrapolation of the recommended practices to all agro-ecological regions of SSA because of the selection of benchmark sites in diverse and representative environmental conditions.
To pilot test soil management and agronomic practices in mulch-based agricultural systems that aim to restore soil fertility, optimize ecosystem service efficiency and increase agricultural productivity, while adapt to and mitigate the adverse effects of climate change and variability in cropping and integrated crop-livestock systems in the moist and dry savannahs of Sub-Saharan Africa (SSA).
To assess economic feasibility and conduct impact assessment of mulch-based farming systems in SSA
To improve soil fertility and soil health by promoting carbon sequestration through the replacement of exported nutrients (especially N, but also P and S to a lesser extent) and by applying the principles of conservation agriculture
To increase on-farm and area-wide ecosystem service efficiency (e.g. nutrient, water, labour and energy use efficiency)
To increase productivity in integrated crop-livestock systems across different spatial scales in the moist and dry savannahs of SSA.
The CRP results provided insights into mulch application technology. Retaining crop residue as soil mulch or soil cover is a proven beneficial soil water management practice which is known to enrich and protect soil and thereby provides better growing environments for a plant or crop. However, there are several limitations to its widespread adoption which includes competition with other usages of crop residue (this is especially true in Sub-Sahara Africa which is the target of this CRP), labor intensive nature and the need of customized crop management practices. For these reasons, widespread adoption of residue mulch will be a slow process in most agricultural systems. Eight publications including 3 IAEA TECDOCS and 5 scientific papers were published from this CRP.
The benefits of mulching and conservation agriculture are manifold, such as it reverses the process of soil degradation, enhance soil biodiversity and provides shelters for natural enemies of pests and is the sink of greenhouse gas in the atmosphere. This CRP sets the basis for subsequent CRPs on crop-livestock integration and climate-smart agriculture (D1.20.12) as well as current CRP on mitigating greenhouse gas emission (D1.50.20). Several long-term trials in the CRP have continued to study the long-term impact of the CRP.