GCRF: CEPHaS - Strengthening Capacity in Environmental Physics, Hydrology and Statistics for Conservation Agriculture Research.

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Two recent El Niño-associated drought seasons in southern Africa have highlighted the vulnerability of agriculture there to climate change. One reason for this is the dependence of much production on the occurrence of sufficient rainfall at the start of the growing season. This is because little water is stored in the soil profile. One strategy for agricultural production, which is attracting a lot of interest in Africa, is "conservation agriculture" (CA). In CA farmers use minimum tillage of the soil and they mulch it with organic materials to reduce water loss. The use of appropriate crop rotations is also key to CA. However, CA cannot be offered as a panacea. Its adoption has different labour demands to those of traditional cultivation, and increased use of herbicides. There may also be competing uses for the mulching materials (animal feed, fuel). Furthermore, the success of CA varies between different soils, and so it may not be universally suitable. The evaluation of CA requires cross-disciplinary input. Part of this must be an evaluation of the extent to which CA can be expected to be more resilient than traditional cultivation under climate change.African members of our established research network run CA trials, some long-term, and engage with policy makers and extension services. They and others have shown that there can be yield benefits from CA, but little is known about how CA affects the behaviour of soil water. In particular, does it improve the soil water supply (and so make production more resilient to delayed rains)? Furthermore, how does CA and its impact on water in the rooting zone affect the recharge of groundwater? There may be synergies if CA improves infiltration of water into the soil, reducing runoff and associated flooding and erosion, but there may also be trade-offs if more water is taken up by plants and does not serve to recharge the groundwater.These gaps in knowlege about CA systems, critical to their full evaluation, arise from gaps in research capacity. This has been identified through critical reflection on CA research by the partnership proposing this project. Core members of the partnership in Africa (Zambia, Zimbabwe and Malawi) and the UK are already engaged together in research on the nutrient status of crops under CA. Collectively we have recognized that the African research centres have uneven experience in the cross-disciplinary science areas that are key to address the questions identified above (soil physics, shallow geophysics, geohydrology and spatial statistics). Partners also lack the equipment and experience needed to undertake observations with modern methods used in soil physics (e.g. in-situ measurement of soil water dynamics). In this project we will undertake learning-centred demonstration trials in all three African countries. At each site existing trials, with CA plots and controls, will be instrumented and sampled so that the fate and behaviour of water under the contrasting systems can be compared. In addition we will undertake statistically designed soil sampling to assess the variability of soils at experimental sites and to support statistical modelling for extrapolation from experimental farms to wider regions. The design of these activities will not reflect a conventional research project but rather will be focussed on capacity strengthening. Planning, execution and publication will be undertaken collaboratively by working groups with staff from all organizations, and the experiences of these groups will be recorded formally to provide a resource for future capacity strengthening at other centres. The activities will be integrated with formal training to develop relevant technical and research skills. The Capacity Research Unit at the Liverpool School of Tropical Medicine are partners and will contribute to development and monitoring of the programme as an exercise in research capacity strengthening.