Evaluation of the Crop Yield and Nutrient Balance by Application of Liquid Manure in Paddy Soil

Abstract

The purpose of this study was to evaluate the effects of liquid manure to increase the yield of green manure inwinter season, and to investigate the effect of green manure incorporation to increase the yield of maize grainand nutrient balance improvement in upland soil. The green manure used in this experiment was barley andhairy vetch with a mixed ratio of barley and hairy vetch (75:25), respectively. Liquid manure applied 0, 26,52, 78, and 104 Mg ha-1, respectively, and the half of the total amount was applied as basal fertilizer, and theother half was topdressing. Nitrogen inputs through liquid manure were 0, 7.1, 15.6, 21.5 and 28.4 kg ha-1,respectively, and the phosphorus inputs were 0, 11.3, 22.6, 33.9 and 45.2 kg ha-1, respectively. The yield ofgreen manure crops increased significantly with the increase of liquid manure application, but the yield ofhairy vetch decreased. In the summer season, the green manure crops were incorporated, and the compost wasused in the conventional treatment. The yield of maize grain increased with increasing green manure yield. The yield of maize grain of green manure crops incorporation treatments was up to 81% compared toconventional cultivation treatment, however the two-year experiments showed an increase on maize grainyields in green manure incorporation treatment. In addition, the incorporation of green manure crops greatlyimproved the phosphorus balance in compared to conventional cultivation. Therefore, productivityimprovement of green manure crops by utilizing liquid manure is thought to have significantly contributed tothe improvement of maize grain yield and nutrient balance.