Interactions of water management and nitrogen application on photosynthetic character and kernel yield and nitrogen use efficiency and water use efficiency in wheat

The Interactions of water management and nitrogen application on photosynthetic character and kernel yield and nitrogen use efficiency and water use efficiency in the high-yielding conditions were studied.The results showed that:(1) In the same irrigation rate,the photosynthetic rate,sucrose-phosphate synthase(SPS) activity and sucrose content in flag leaf and kernel yield increased,but kernel weight,nitrogen(N) harvest index and N apparent recovery rate decreased as the nitrogen application rate increased.(2) In the same nitrogen application rate,the photosynthetic rate,SPS activity and sucrose content in flag leaf of W1,W2 and W3 showed no significant difference during 0～14 d after anthesis;but which of W3 were higher than W1 and W2 significantly 21 days after anthesis.The kernel weight of W1 and W2 had no significant difference,but all higher than W3.(3) In N0 and N1 levels,the yield of W3 were higher than W1 and W2,but it was quite the contrary under N2 level;the N apparent recovery rate and N productive efficiency of different treatments presented as: W0W1,W2W3;while water-use efficiency of different treatments were presented as: W3W2W1W0.In this experiment,with water irrigated at pre-sowing,jointing and ahthesis,and 210 kg/hm2 nitrogen applied,the yield,water use efficiency and nitrogen use efficiency were higher.