不同秸秆还田方式对北方超级稻氮素吸收利用的影响

Effects of Different Straw Return Modes on Nitrogen Absorption and Utilization of Super Rice in Northern China

以北方超级稻沈农265为试验材料,研究了秸秆直接还田和秸秆热解成生物炭施入对水稻氮素吸收利用的影响。结果表明:与常规生产相比,秸秆直接还田主要提高了水稻生育中期的叶、茎含氮量,但同时降低了后期穗氮素累积量,氮素回收率、生理利用率和氮肥农学利用率分别下降5.28%、11.65%和16.19%,使产量有降低趋势;少量秸秆生物炭施入有助于提高生育中后期叶、茎含氮量并促进穗氮素累积量增加,氮素回收率和氮肥农学利用率分别增加6.02%和7.71%,有增加产量的潜力;大量秸秆生物炭施入降低了叶、茎和穗含氮量,氮素回收率负向效应强度高达34.31%,但氮素生理利用率增加45.62%,不利于产量的提高。秸秆直接还田和大量秸秆生物炭施入对水稻氮素吸收有一定抑制作用且不利于产量的提升,少量秸秆生物炭施入则能提高水稻氮素利用率并增加产量。

The super rice in Northern China‘Shennong 265’was used to study the N use efficiency under straw and biochar addition on soil.The results showed that:straw application improved the nitrogen content of leaf and stem in mid-growing stage,reduced nitrogen accumulation of panicle,decreased nitrogen recovery efficiency,physiological efficiency and agronomic efficiency by 5.28%,11.65%and 16.19%,respectively,thereby reduced the yield.A small amount of biochar addition was helpful to improve the nitrogen content of leaf and stem,and nitrogen accumulation of panicle in the late growth stage,increased nitrogen recovery efficiency and agronomic efficiency by 6.02%and 7.71%,respectively,and had a positive effect on yield.A large amount of biochar decreased nitrogen content of leaf,stem and panicle,reduced nitrogen recovery efficiency by 34.31%,but increased the nitrogen physiological efficiency by 45.62%,and had a negative effect on yield.Straw and large amount of biochar can inhibit the absorption of nitrogen and have a negative effect on yield of rice,however a small amount of biochar can improve the utilization rate of nitrogen and yield.