Effects of Different Tillage and Nitrogen Rates on Yield of Wheat and Maize Cropping System

Minimum tillage,no-tillage and straw returning play an important role in improving ecological environment,fertilizing the soil fertility,increasing crop yield and improving resource utilization efficiency.The effects of tillage modes and nitrogen application rates on yield and net output value of wheat and maize in two cropping system were studied in this experiment.The results showed that with the decreasing of nitrogen application,spike number per hectare of wheat and yields of wheat and maize decreased,so the total yield decreased.Under the rotary tillage,harrow tillage and no-tillage,with the reducing of nitrogen rate,the grains per spike of wheat decreased while the 1000-grain weight of wheat increased,but the 1000-grain weight of maize had a same trend with change of nitrogen rates.The yield of conventional tillage with 100% N,harrow tillage with 100% N and no-tillage with 100% N were the higher,and then that of rotary tillage with 100% N conventional tillage with 75% N and no-tillage with 75% N.The net output value of harrow tillage with 100% N and no-tillage with 100% N were higher than conventional tillage with 100% N.So the treatments of harrow tillage with 100% N and no-tillage with 100% N had the higher economic benefit and were suit for extended widely.