Wayan Sabe Ardjasa1), Ho Ando2), and Makoto Kimura3
Soil Sci.Plant Nutr. 47-1, 101-112 (2001)
Key Words: calorie and protein yield, cassava, erosion,
cropping system
Soil erosion and crop production from the view point of
nutritional balance for family consumption in upland cropping systems were
evaluated over period of 9 years. 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.