摘要:
以天优3301为材料,研究不同施氮量对优质稻产量及干物质生产的影响。结果明确,稻谷产量与施N量呈抛物线型相关,达到最高产量的施氮量为205.06 kg·hm-2,相应产量为10 350.83 kg·hm-2;达到最佳经济效益的施N量为192.70 kg·hm-2,相应产量为10 341.37 kg·hm-2。每生产100 kg稻谷的最高施N量为1.98 kg,经济施N量1.86 kg。适宜施N量的处理,穗多穗大,每平方米总粒数多,结实率高,产量高;施N偏多或偏少,产量都降低。适中的施肥水平,中、后期有较高的干物质生产力,不仅抽穗前积累了较多的贮藏性物质,抽穗后也生产较多的净光合产物。群体生长率(CGR)在本田营养生长期与施N量呈线性正相关,在中、后期与施N量呈抛物线型相关。可见为了提高中、后期的群体生长率,必须维持较高的供氮强度。
关键词:
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优质稻
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施氮量
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产量
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干物质生产
Abstract:
Effects of nitrogen (N) fertilization on yield and dry matter content of the high quality rice, Tianyou 3301, were studied. The results showed that the grain yield correlated to N application. The optimal N application was determined to be 205.06 kg穐m-2 for the highest yield of 10 350.83 kg穐m-2. The economical N application was 192.70 kg穐m-2 that would provide an estimated yield of 10 341.37 kg穐m-2. To produce 100 kg of the grains, the highest and the most economical N application rates were 1.98 and 1.86 kg, respectively. An optimum N application could produce more and bigger spikes, more total spikelets per m2 as well as higher seed set than otherwise. Either higher or lower application rate would result in lowered yields. Furthermore, moderate levels of the N fertilization could increase the dry matter productivity during the middle and later growth period, as well as the stored substances accumulated before the heading and the photosynthetic substances produced after the heading. The crop growth rate (CGR) had a linear correlation with the N application in field vegetative growth period. They had a parabolic correlation in the middle and late growth period. Consequently, in order to improve CGR in the middle and late growth period, heavy N fertilization needed to be implemented.
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