水稻孕穗期在淹涝胁迫下施肥的优化选择及其作用机理

Optimum Fertilization and Its Corresponding Mechanism under Complete Submergence at Booting Stage in Rice

采用正交试验与对比试验相结合 ,研究了 N、P、K、Zn、Si肥和栽培密度各因子及其优化处理对孕穗期完全淹涝胁迫下早稻产量的影响与作用机理。结果表明 ,不同 N肥和 K肥水平对产量的影响达到了显著水平差异 ,其各自的最适用量分别约为纯氮 135 kg/ hm2和纯钾 12 0 kg/ hm2 ;适 N高 K能明显提高水稻的耐淹涝胁迫能力 ,N/ K比宜介于 1.1～ 1.5之间。P肥以过磷酸钙 75 0 kg/ hm2最优 ,其它因子的影响较小 ,但具有较好的互作效应。多元肥料优化处理能显著减少洪涝灾害对水稻产量的损失 ,其机理在于多元肥料的有机结合 ,提高了水稻细胞内可溶性糖的含量 ,减少了受淹水稻植株体内无机氮的积累 ,使次生高位分蘖发生频率和纹枯病发病指数显著下降 ,实粒数和有效穗大幅度增加。

The combined effect and mechanism of N, P, K, Zn, Si and culture density on grain yield of rice under complete submergence at booting stage in field were studied with orthogonal and control experiment. It showed that the effect of N and K on grain yield of rice under complete submergence was extremely significant, and the fittest usage was pure N 135 kg/hm 2 and pure K 120 kg/hm 2 respectively. Combination of high K with low N was advantage to rice under submergence and suitable ratio of N/K was about 1.1~1.5. Difference between various level of P was not significant, but the usage of 750 kg/hm 2 was superior to others. Effect of Zn, Si and culture density on grain yield of rice under complete submergence at booting stage was small respectively except for their mutual effect. The wholesome effect of suitable fertilization combination lied in the increase of soluble carbohydrate and decrease of inorganic nitrogen in cell, which resulted in the decrease of high bud percentage and index of rice stripe disease. It also highly ameliorated the spikelet fertility and increased the number of panicle.