Effects of straw returning and nitrogen application management on dissolved nitrogen components in farmland soil
In order to understand the effects of straw returning and nitrogen(N)application management on dissolved N transformation characteristics in farmland soil,and to study the straw-returning technology with improving soil N supply capacity for Northeast cold area of China,with a continuous in situ-field experiment,the dynamics of inorganic N(IN),dissolved organic N(DON)and dissolved total N(DTN)affected by different straw returning methods(no straw-returning,crushed straw-returning ploughing,decomposed straw-returning rotary tillage)and N application management(N 180,210,240 kg/hm2;one-time N application,postponing N application)were investigated.The results showed that,the straw-returning with N application affected soil dissolved N components content,and its behavior was simultaneously affected by straw-returning methods,N application models and growing stages.Compared with no straw returning,the IN and DTN in soil treated with straw returning with low N application rate(N 180 kg/hm2)both decreased,however,increased in soil treated with straw returning with high N application rate(N 240 kg/hm2);DON in the straw returning treated soil increased significantly during the early growth stages(sowing stage to jointing stage),and changed with no rule during later growth stages.With the increasing of N application rate,IN and DTN in soil treated with straw returning both increased significantly,however,DON increased significantly only during spring maize exuberant growing period(jointing stage to filling stage).With maize growing,IN,DON and DTN for the straw-returning treated soil all showed a double-peak curve with decreasing peak value,except for the three-peak curve of DON in the decomposed straw-returning rotary tillage soil.Overall,the technology of crushed straw-returning ploughing with 15％N fertilizer at the rate of N 210 kg/hm2 had the potential to improve N management and enhance soil fertility in the agricultural producing areas of Northeast China.
straw returningnitrogen applicationinorganic nitrogendissolved organic nitrogendissolved total nitrogen
万方数据
维普
