Yield and soil erosion among cassava-based cropping patterns in South Sumatra

Abstract

Soil erosion and crop production from the viewpoint of nutritional balance for family consumption in upland cropping systems were evaluated over period of 9 y. Cassava-based cropping pattern was adopted from the 1987/88 to 1989/90 cropping seasons and cassava cultivation with an intercrop was compared with other sequential cropping patterns from the 1990/91 to 1995/96 cropping season. The experiments were conducted in fields with Red-yellow Podozolic soil in Central Lampung, South Sumatra, Indonesia. The results obtained were as follows: 1) The yield of cassava planted in monoculture decreased from year to year without fertilizer application. In contrast, with fertilization, the yield was high and constant. The yield of cassava depended on the growth duration of cassava. The yield of upland rice and maize in monoculture was 2 to 4 times higher than that of intercropped upland rice and maize. 2) Cassava cultivation with intercropping of upland rice and maize as the first intercrop followed by peanut or soybean as the second intercrop or sequential cropping pattern of maize-maize performed well from the view points of yield and production of calorie and protein. 3) The amount of eroded soil during the first 4-month period in the rainy season was about 90% of the annual amount. Cassava cultivation with intercropping of upland rice and maize as the first intercrop reduced the amount of soil erosion. Soil erosion decreased appreciably from year to year. 4) Cassava intercropped with upland rice and maize followed by peanut or soybean was suitable from the view points of crop yield and maintenance of soil fertility in upland areas with Red-yellow Podzolic soil.