Influence of nitrogen fertilizer distribution on production and nitrogen use recovery within the rotation of winter wheat and summer maize

Effective nitrogen management remains one of the most challenging tasks for sustainable agriculture.This field experiment was conducted in a randomized design with four replicates to study on the influence of nitrogen distribution on biomass,yield,net return,nitrogen agronomic efficiency and nitrogen use recovery within the rotation of winter wheat and summer maize based on the amount of nitrogen controlled(N 420 kg/hm2).The results showed that the proportion of nitrogen distribution significantly affected the yield,net return and nitrogen use efficiency within the rotation of winter wheat and summer maize.Under the condition of 420 kg/hm2 nitrogen application,the proportion of 55%(N 231 kg/hm2)applied on winter wheat and 45%(N 189kg/hm2)for summer maize could help obtain the highest production(13 026 kg/hm2)and net return(22 146 yuan/hm2),and the agronomic efficiency and recovery of nitrogen fertilizer was increased.This indicated that the proportion of nitrogen distribution within the rotation of winter wheat and summer maize was feasible for southern region of Shanxi province.As far as nitrogen rate of wheat season was concerned,the nitrogen rate of 189 kg/hm2 could obtain higher yield and higher nitrogen efficiency.It was noteworthy pointing out that crop growth stage suffered from adverse weather leading to nitrogen agronomic efficiency and nitrogen use recovery was relatively lower with the average value only 4.6 kg/kg and 20.8%,respectively.