Effect of tillage practice on nitrogen use efficiency of wheat in the farming-pasture zone

In order to explore the effects of different tillage modes on yield and nitrogen use efficiency (NUE) in winter and soil physical properties, the experiment was conducted in a farming-pasture zone in Chifeng City of Inner Mongolia Autonomous Region, North China from 2008 to 2010. Three tillage modes of Conventional Tillage (CT), No Tillage with Stubble (NTS), Straw Mulch (SM) were applied in the experiment to compare the effect of the tillage modes: on soil physical properties, the grain yield and quality and nitrogen use efficiency (NUE) of N supplies in winter wheat. The results showed that conservation tillage can improve the soil structure, increase the soil water content, non-capillary porosity, grain yield and protein content, and improve the processing quality properly by long-term implementation of NTS and SM. Under such conditions, the NUE was increased by 3% ∼ 4% with N-fertilizer residues in the soil decreased by about 1%, and N-fertilizer loss dropped by about 2%, correspondingly, which greatly decreased the pollution of N-fertilizer on farmland under conservation tillage. In addition, the wheat NUE of the residual N in last season was less affected by the tillage mode. (authors)