Effects of integrated straw on crop yield and nitrogen balance in winter wheat & summer maize

The current experiment was carried out in Hua Country town of He'nan Province to study the effects of integrated straws on crop yield and nitrogen balance in winter wheat summer maize in the growing season of 2006～2007.The experiment had 10 treatments: Nitrogen rate of N0,N90,N180,N270,and N360(kg/hm2),with and without crop residue incorporation to soil,respectively.Compared with the treatments with nitrogen fertilizer only,straw incorporation plus nitrogen fertilizer of N90,N180,N270,and N360(kg/hm2),respectively,increased winter wheat grain yield by 7.1%,8.4%,9.5%,11.1%,and 10.2%,increased summer maize grain yield by 5.8%,9.5%,10.1%,and 9.0%.The S+N 270 treatment had the largest amount and increasing tatio of grain yield.In order to keep the nitrogen balance during one year,It is suitable to straw incorporation plus purity nitrogen to apply purity nitrogen to winter wheat and summer maize do not surpass 360 kg/hm2,360～540 kg/hm2.