Effects of intercropping with maize on the micro-environment, growth and yield of cassava

The growth environment of cassava intercropped with maize differs from monocultures of cassava. A trial was conducted to determine the effects of intercropping with maize on micro-environment, growth and yield of cassava. Radiant energy reaching the soil surface and maximum diurnal soil temperatures were lower with intercropping, with the lowest values being observed in the fertilized plots. Similarly, soil moisture content and earthworm activity were greater with intercropping, with the highest values occurring in fertilized plots. Soil fertility, especially N, was lower in intercropping than in cassava grown alone, with the lowest fertility occurring in non-fertilized mixtures. Intercropping with fertilizer application thus lowered exposure and temperature, and increased soil water and earthworm activity. Inclusion of maize with cassava increased plant height, reduced leaf area index and stem branching and diameter, favoured lodging, delayed bulking of storage roots and decreased nutrient uptake in cassava. The ability of cassava to compensate for impaired early growth after maize harvest depended strongly on soil fertility, especially the level of nitrogen.