No-tillage and fertilization management on crop yields and nitrate leaching in North China Plain.

A field experiment was performed from 2003 to 2008 to evaluate the effects of tillage system and nitrogen management regimes on crop yields and nitrate leaching from the fluvo-aquic soil with a winter wheat (Triticum aestivum L.)-maize (Zea mays L.) double-cropping system. The tillage systems consisted of conventional tillage (CT) and no-tillage (NT). Three nitrogen management regimes were included: 270 kg N ha(-1) of urea for wheat and 225 kg N ha(-1) of urea for maize (U), 180 kg N ha(-1) of urea and 90 kg N ha(-1) of straw for wheat and 180 kg N of urea and 45 kg N ha(-1) of straw for maize (S), 180 kg N ha(-1) of urea and 90 kg N ha(-1) of manure for wheat and 180 kg N ha(-1) of urea and 45 kg N ha(-1) of manure for maize (M). An array of tension-free pan lysimeters (50 cm × 75 cm) were installed (1.2 m deep) to measure water flow and [Formula: see text]-N movement. No significant effect of the N management regime on yields of winter wheat and maize grain was found in the 5-year rotation. Tillage systems had significant influences on [Formula: see text]-N leaching from the second year and thereafter interacted with N management regimes on [Formula: see text]-N loads during all maize seasons. The average yield-scaled [Formula: see text]-N leaching losses were in order of CTS < NTS< CTU < NTU <CTM < NTM, ranging from 0.88 (CTS) to 6.07 (NTM) kg N Mg(-1) for winter wheat system and from 0.99 (CTS) to 6.27 (NTM) kg N Mg(-1) for summer maize system for 5 rotation years. The results showed that CTS decreased the yield-scaled [Formula: see text]-N leaching losses while sustaining crop grain yields. Considering the lower costs, NTS could be a potential alternative to decrease yield-scaled [Formula: see text]-N leaching losses and improve soil fertility while maintaining crop yield for the winter wheat-maize double-cropping systems in the North China Plain.