Yield and profitability of corn and soybean under different tillage in the black soils of Northeast China

The effect of no-tillage (NT) and conventional tillage on yield and economic benefit of corn and soybean was studied to provide practical information for promoting conservation tillage in Northeast China. The experiment was established in Dehui County, Jilin Province, in the fall of 2001. We compared continuous corn, corn-soybean rotation and corn-corn-soybean cropping systems under different tillage treatments—no-tillage (NT), fall plough (FP) and ridge tillage (RT). The results show that under NT, the number of field operations for corn and soybean is 3~6 times less than under RT and FP respectively. The effect of different tillage treatments on corn yield is insignificant before 2006. Corn yield in RT is highest (10 136 kg·hm^-2), 12.3% higher than continuous corn under NT. However, differences in corn and soybean yield under different tillage treatments are insignificant. Production cost decreases in the following order: FP＞NT＞RT for corn and FP＞RT＞NT for soybean. The profitability of corn differs in the following order: RT＞NT＞FP (for continuous corn), RT＞NT＞FP (for corn-soybean rotation) and NT＞RT＞FP (for corn-corn-soybean system). The 5-year study shows, with the exception of continuous corn, that conservation tillage does not lead to a decrease in crop yield. The rotation of corn and soybean in NT treatment gives approximately equal corn yield and even higher soybean yield compared to FP and RT treatments. Under NT, cost of labor and machinery drops, hence profitability surpasses that of FP. In conclusion, we recommend further studies on long-term effect of these cropping systems.