Effect of postponing N application on the yield, apparent N recovery and N absorption of winter wheat

Two field experiments were carried out to study the effect of postponing N fertilizer application on the yield, apparent N recovery and N absorption of winter wheat. The objective of this experiment was to find the pattern of N absorption and transformation, and to give a scientific suggestion for high-yield management and optimized N application of winter wheat. The results showed that postponing N fertilizer application can increase grain yield, number of spike and apparent N recovery of winter wheat, with treatment N4 (50% basal fertilizer, 50% application in stem elongation stage) having the best results. The yield of two field experiments reached 3857 and 8240 kg/hm2， increased yield by 25.8% and 17.3%, spike number by 6.0% and 18.1%, apparent N recovery by 111.8% and 107.4%, respectively. The majority of N absorption and accumulation in winter wheat took place from regreening to filling, so on the basis of basal fertilizer application, it is very important to apply N fertilizer after regreening. Based on results from this experiment, it is recommended that 50% of N fertilizer should be applied as basal fertilizer and 50% should be applied after regreening.