氮肥管理对^15N标记水稻秸秆氮吸收利用的影响

Effects of nitrogen fertilizer management on nitrogen uptake and utilization of^15N labeled rice straw

利用^15N同位素示踪技术,通过盆栽模拟试验揭示氮肥管理方式对水稻秸秆氮吸收利用的影响,设置基肥氮素在插秧前施入和基肥氮素与秸秆同时施入(调节C/N)两个处理,试验结果表明,秸秆中的氮素可以作为下茬作物生长的有效氮源;基肥氮素与秸秆同时施入(调节C/N)处理秸秆氮的利用率显著高于基肥氮素在插秧前施入,水稻从^15N秸秆标记物中摄取氮的比例(NdfS)明显低于土壤肥料中氮(NdfS+F);水稻地上植株对秸秆氮的综合利用率为6.51%~7.99%,其中,茎叶秸秆氮利用率为1.40%~1.75%,穗利用率为5.11%~5.25%。在秸秆还田的条件下,基肥氮素与秸秆同时施入,可以显著提高水稻对秸秆氮素的吸收能力。

Using^15 N isotope tracer technique,the effects of nitrogen fertilizer management on nitrogen uptake and utilization of rice straw were revealed through pot simulation experiments.Two treatments were set up in the experiment:the application of base nitrogen fertilizer before transplanting(T1)and the application of base nitrogen fertilizer and straw at the same time with adjusting C/N ratio(T2).The results of pot experiment showed that nitrogen use efficiency of T2 treatment was significantly higher than that of T1 treatment.Nitrogen uptake by rice from^15N straw(NdfS)was significantly lower than that in soil and fertilizer(NdfS+F).The comprehensive utilization rate of straw nitrogen for rice aboveground plants was 6.51%~7.99%,of which the utilization rate of straw nitrogen for stems and leaves was 1.40%~1.75%,and the utilization rate for panicles was 5.11%~5.25%.Under the condition of straw returning to the field,the nitrogen absorption capacity of rice to straw cloud be significantly improved by applying base fertilizer and straw simultaneously.