Abstract—Three years of cassava + maize intercropping experiments were conducted to study the effect of planting cassava for forage production on cassava forage and root yields and on soil quality. The experiments were also designed to minimize the decrease of soil quality due to planting cassava for forage production. The experimental treatments include two cassava plant spacings (1.0×0.8m and 1.0×0.4m) and four different level of nitrogen fertilizer application (135; 180; 235 and 270kg N/ha). As the control treatment, cassava was planted without any pruning during the cassava crop cycle. These nine treatments were arranged in a Randomized Block Design with three replications. The results indicate that regular pruning of cassava plants for forage production decreased soil quality, especially soil carbon and soil nitrogen. Application of nitrogen fertilizer increased forage yield; however, the increase in nitrogen rate from 225 to 270kg N/ha did not further increase forage yield. The application of additional nitrogen fertilizer did not maintain soil quality. Indeed, application of nitrogen fertilizer could minimize the decrease of soil nitrogen, but it could not avoid the decline of crop yield. With the highest nitrogen rate, after three years of planting cassava + maize in an intercropping for forage production system, the crop yields obtained at 1.0×0.8m spacing were: 3.24t/ha for the intercropped maize; 14.08t/ha for cassava roots; and 6.48t/ha cassava forage. The yield of the first year of these treatments was: 3.97t/ha for maize; 18.09t/ha for cassava roots; and 7.73t/ha cassava forage.
 

Index Terms—soil carbon content, nitrogen fertilizer, maize yield, mixed cropping

Cite: Wani H. Utomo, Erwin I. Wisnubroto, and R. H. Howeler, "Cassava Planting for Biomass Production and Soil Quality in the Cassava + Maize Intercropping System," Journal of Advanced Agricultural Technologies, Vol. 3, No. 2, pp. 89-93, June 2016. Doi: 10.18178/joaat.3.2.89-93