氮肥运筹对滨海稻区钵苗机插水稻产量及氮肥利用率的影响

摘要

To determine the appropriate nitrogen application for mechanized pot-seedling transplanting rice cultivation in the future,a field experimentation using the high salinity tolerant super rice,Yanfeng 47,was conducted in a coastal area in Liaoning.Rice yield and nitrogen utilization under varied nitrogen fertilization were evaluated.It was found that when the basal fertilizer ∶ first-tillering-fertilizer ∶ second tillering-fertilizer ∶ first panicle-fertilizer ∶ second panicle-fertilizer was 40 ∶12 ∶ 18 ∶ 16 ∶ 14 was applied,the greatest grain yield of 10.79 t · hrn-2 was reached.The productivity was extremely significantly higher,with much higher panicles and spikelets and filled grain numbers per ear,than those provided by the other application modes.Its 41.90％ nitrogen utilization efficiency was also significantly higher than that of other treatments.The nitrogen absorption rates of the mechanically transplanted pot-seedlings during the stages from transplanting to tillering,from tillering to jointing,from jointing to heading,and frrom heading to maturity were approximately 16 ∶ 53 ∶ 20 ∶ 11.The amount of nitrogen absorption before the jointing was 69％ of the total nitrogen absorption,and the amount of nitrogen absorbed by the reproductive growth was 31 ％,the ratio was coincide with that of basic-tillering to panicle of the treatment with highest yield and nitrogen use efficiency.Hence,if only one available nitrogen fertilizer was applied with a total N application rate at 240 kg · hm-2,the ratio of basal fertilizer ∶ first tilleringfertilizer ∶ second tillering-fertilizer ∶ first panicle-fertilizer ∶ second panicle-fertilizer at 40 ∶ 12 ∶ 18 ∶ 16 ∶ 14 would be appropriate for the plant growth as well as the absorption and utilization of nitrogen for the mechanically transplanted rice in the region.Then,further demonstrations could be conducted to promote the application.Moreover,the nitrogen agronomy efficiency and the nitrogen partial factor productivity were found useful as indicators for evaluating the nitrogen utilization.%为了筛选适宜钵苗机插水稻的氮肥施用方式,以滨海稻区超级稻盐丰47为材料,研究不同氮肥运筹方式对钵苗机插水稻产量及氮肥利用率的影响.结果表明,当氮素按基肥:1次蘖肥∶2次蘖肥∶1次穗肥∶2次穗肥=40∶12∶18∶16∶14比例施用时,其收获穗数、颖花量和穗实粒数均较大,产量最高,达到10.79 t·hm-2,极显著高于其他处理.该处理的氮肥利用率达到41.90％,显著高于其他处理.钵苗机插水稻移栽～分蘖期、分蘖～拔节期、拔节～齐穗期、齐穗～成熟期这4个阶段吸氮比例之间的比例约为16∶ 53∶20∶ 11,拔节前氮素吸收量占总吸氮量的69％,进入生殖生长后氮素吸收量占总吸氮量的31％,这一比例和产量、氮肥利用率较大的处理茎蘖肥和穗肥比例相吻合.因此,在仅施用速效肥料的前提下,氮肥总施用量为(N∶ 240 kg·hm 2),且氮素以基肥:1次蘖肥∶2次蘖肥∶1次穗肥∶2次穗肥=40∶12∶18∶16∶14时,适宜滨海稻区钵苗机插水稻的生长发育及对氮素的吸收利用,可以进一步示范推广.此外,可以将氮肥农学利用效率、氮肥偏生产力作为衡量氮肥利用率高低的指标.