Achieving adequate soil cover to improve soil-water relations
and reduce surface crusting in CA rotations may be difficult for
smallholder farmers in eastern and southern Africa using only in
situ biomass production. Farmers may be able to compensate for
low biomass production, removal of biomass for other purposes,
and rapid residue decomposition by intercropping agroforestry
trees or relay cropping with green manure cover crops or short
duration grain legumes. In the 1st year of this study, pigeonpea
intercropping did not add significant biomass when intercropped
with sweet potato or cassava. When pigeonpea was coppiced and
allowed to grow back a second season, vegetative growth was
vigorous and intercropping added significant biomass. However,
agroforestry intercrops can compete with annual crops for soil
moisture, nutrients, and sunlight, which was observed in this study
when pigeonpea out-competed soybean in CAR, resulting in crop
failure