Effects of Chicken Manure Application on Growth, Yield and Soil Chemistry in the Cultivation of Soybean and Corn for Grain Use

Abstract

For establishing a large-scale paddy field crop rotation system with reduced chemical fertilizers, soybean with which nitrogen chemical fertilizers can be reduced and corn which can be cultivated in a labor-saving manner were cultivated in the same field. Then the effects of chicken manure application on the growth, yield and soil chemistry were investigated. In soybean cultivation, nitrate nitrogen in the soil at the early growth stage was higher and the amount of root nodules was lower with the chicken manure treatment than with the chemical fertilizer or without fertilizer. In corn cultivation, the nitrate nitrogen in the soil at the early growth stage and the nitrogen absorbed during the silking stage were slightly higher in the chicken manure treatment than with the chemical fertilizer. These fertilization treatments, however, had almost no effect on the yields of soybean and corn. These results show that chicken manure or no fertilizer in the soybean cultivation and chicken manure in the corn cultivation can maintain the same yield as the chemical fertilizer. Judging from the chemical components in the soil loaded from fertilizer and unloaded into grain, N, P₂O₅, and K₂O were estimated to decrease without fertilizer in soybean and increase largely with the chicken manure treatment in corn. This suggests that the combination of these cultivation methods is suitable for a paddy field rotation system with reduced chemical fertilizers.