Effects of Biogas Slurry and Straw Returning on Soil Nitrogen and Phosphorus Leaching
To provide theoretical support for agricultural waste utilization and field non-point source pollution prevention,the effects of biogas slurry and straw returning on nitrogen and phosphorus concentration and leaching in soil were studied.The experiment set four treatments of control(CK),conventional N application(CON),optimized N application(OPT)and whole straw manuring plus biogas slurry returning(SMB).The crop yield,soil nitrate residuals and total P leaching were determined for analysis of soil N and P concentration and leaching characteristics.The results showed that crop yield under SMB treatment were reached 99.6％and 95.4％,N and P absorption attained 84.9％,78.4％and 85.7％,82.4％than those of CON and OPT treatment,respectively,which N and P agricultural efficiency of SMB treatment was increased by at least 13％.Under SMB treatment,soil nitrate concentration and leaching were decreased by 43％and 77.3％respectively,which the apparent leaching coefficient was 4.83％.The residuals in SMB treatment were 28.9％of chemical N fertilizer application treatment.The P leaching with SMB averaged for 0.045 kg/hm2,and soil inorganic P concentration was 80.7％of chemical P fertilization,which 80％inorganic P converted into Fe-P and Ca-P.Meanwhile,under SMB treatment higher and medium active organic soil P occupied by 55.8％,which was significantly higher than that of conventional P fertilization of 34.2％,indicating biogas slurry and straw returning to filed facilitated various forms of P availability.Thus,straw and biogas slurry returning to field is an environment-friendly waste resource utilization ways in China.
biogas slurry and straw returningcrop yieldresource utilization efficiencyN and P leachingP forms
万方数据
维普
