施氮对稻茬冬小麦氮肥吸收利用及转运的影响

Effect of Nitrogen Applicationon Nitrogen Uptake,Utilization and Translocationin Winter Wheat in Rice-Wheat Rotation

为推动稻茬冬小麦氮肥高效利用,采取15N微区试验,研究了施氮量(N0、N120、N210、N300)对稻茬小麦氮素吸收、转运、产量和氮肥利用的影响。结果表明,增加施氮量能够显著提高成熟期植株对肥料氮和土壤氮的吸收量。小麦对基肥氮的吸收以越冬至拔节期最高,对追肥氮的吸收以拔节至开花期最高。植株对追肥氮的积累量均高于基肥氮,对土壤氮的积累量在N120处理下高于肥料氮,在N210、N300处理下则相反;N120、N210、N300处理下植株中土壤氮积累量占总吸氮量的比例分别为57%、48%、45%。成熟期叶片、茎鞘、穗轴+颖壳和籽粒中的氮素分配比例分别为6.09%~9.70%、9.01%~11.14%、7.19%~7.48%、71.96%~77.42%。肥料氮对籽粒氮素的贡献率随施氮量增加而显著增加,N120、N210、N300处理分别为45.78%、56.22%、61.25%。植株中肥料氮的转运量、花后积累量和土壤氮的花后积累量均随施氮量增加而显著增加,而土壤氮的转运量则随施氮量的增加而下降。基肥氮、追肥氮、肥料氮和土壤氮的转运效率分别为77.31%~79.96%、77.89%~81.80%、77.61%~81.13%、51.55%~67.64%。植株花后氮积累量对籽粒氮素的贡献率约为1/5,肥料氮和土壤氮花后积累量对籽粒中肥料氮和土壤氮的贡献率分别为9.59%~14.56%和24.11%~34.48%。施氮量超过210kg·hm^-2时产量增加不显著,N120、N210、N300处理氮肥回收率分别为54.48%、48.15%、41.64%。

In order to promote nitrogen use efficiency of winter wheat after rice stubble,a field 15 Ntracer experiment were conducted to study effects of nitrogen application:0(N0),120(N120),210(N210)and 300(N300)kg·hm^-2,on nitrogen uptake,translocation,recovery and yield of winter wheat inrice-wheat rotation.The results showed that the absorption amount of fertilizers nitrogen and soil nitrogen increased with the increase of nitrogen application rate.The basal fertilizer nitrogen uptake of plant was highest at the overwintering and jointing stages,and the topdressing nitrogen uptake was mainly during jointing to flowering stage.Nitrogen accumulation of topdressing fertilizer under different treatments was higher than that of base fertilizer;soil nitrogen uptake was higher than fertilizer nitrogen under N120 treatment,but an opposite trend was found under N210 and N300 treatments.The proportion of soil nitrogen under N120,N210 and N300 treatments was 57%,48%,and 45%,respectively.Nitrogen distribution ratios were 6.09%-9.70%,9.01%-11.14%,7.19%-7.48%,71.96%-77.42%for leaves,stems and sheaths,cobs+glumes and grains at maturity stage.The contribution rates of fertilizer nitrogen to grain nitrogen under N120,N210 and N300 treatments were 45.78%,56.22%and 61.25%,respectively,which increased significantly with the increase of nitrogen application rate.The amount of plant fertilizer nitrogen transfer,post-anthesis accumulation and soil nitrogen post-anthesis accumulation all increased significantly with increasing nitrogen application,while soil nitrogen transfer decreased with increasing nitrogen application.The total transfer efficiency of base nitrogen,topdressing nitrogen,fertilizer nitrogen and soil nitrogen were 77.31%-79.96%,77.89%-81.80%,77.61%-81.13%,and 51.55%-67.64%,respectively.The contribution rate of post-anthesis nitrogen accumulation to grain nitrogen was about 1/5.The post-anthesis accumulation amounts of fertilizer nitrogen to grain fertilizer nitrogen and soil nitrogen ranged from 9.59%to 14.56%,and from 24.11%to 34.48%,respectively.Yield did not increase significantly when the nitrogen application rate exceeded 210 kg·hm^-2,and the nitrogen fertilizer recovery rates of N120,N210 and N300 were 54.48%,48.15%and 41.64%,respectively.