不同施氮量对免耕移栽杂交水稻干物质积累与运转的影响

Effects of Different N Application Rate on the Matter Accumulation and Translocation of Transplanted Hybrid Rice under No-tillage Condition

[目的]研究施氮量对免耕移栽杂交水稻干物质积累与运转的影响。[方法]以超级杂交水稻黔南优2058为试材，设5种施氮量处理进行免耕移栽的稻作试验。[结果]随着氮肥施用量的增加，水稻生育中、后期的干物质积累量均有增加的趋势，在最高分蘖期和孕穗期茎干物质减少，叶干物质逐渐增加；在齐穗期茎、叶干物质逐渐减少，穗干物质比例和穗／茎叶逐渐增加；成熟期的情况与齐穗期相反。在75～225kg／hm^2施氮量范围内，随着施氮量的增加，茎鞘物质输出率、茎鞘物质转换率、抽穗后茎叶干物质表观输出量和输出率、每穗总粒数、结实率和千粒重逐渐下降，而有效穗数逐渐升高。[结论]随着施氮量的增加，水稻产量以抛物线形式增加，施氮量为284．0kg／hm^2，可获得最高产量。

[ Objective ] The study aimed to investigate the effect of N application on the matter accumulation and translocation of transplanted hybrid rice under no-tillage condition. [ Method] With the super hybrid rice Qiannanyou 2058 as the tested material, 5 treatments of different N application rate were set up to make the rice cropping test with no-tillage and transplanting. [ Result] With the increment of N application rate, the dry matter accumulation in rice was increased gradually in the middle and latter growth stages and that in the stem was decreased and that in leaf was increased gradually in the maximum tillering stage and booting stage. The dry matter accumulation in stem and leaf was decreased gradually and that in panicle and panicle/stem and leaf in full heading stage was increased gradually, and that in mature stage exhibited a reverse trend. In the N apphcation rate of 75 - 225 kg/hm^2 , the dry matter exportation rate and transformation rate from stems and sheaths, the apparent transportation amounts and ratio of dry matter in stems and leaves after heading, total spikelet number and grain setting rate per panicle, and 1 000-grain weight were gradually reduced with the increment of N application rate, whereas the effective panicle number was increased gradually. [ Conclusion] The yield of rice increased in parabola with the increment of N application rate, and the highest yield could be obtained when the N application rate reached 284.0 kg/hm^2.