淮北地区机插超级粳稻产量形成及氮素吸收利用特征

摘要

The aim for this study was to research the yield formation and characteristics of nitrogen utilization about super japonica rice in Huaibei Area. A field experiment was conducted using medium-maturing medium super japonica rice and non-super japonica rice cultivars(contrast) as materials, investigating the effects of different nitrogen application levels(0, 225, 300 kg/hm2). The results showed that, with the increase of N application amount, the grain yield of super japonica rice increased continuously. The highest av-erage grain yield of the super japonica rice cultivars was 10.98% higher than that of the contrast. Compared with the contrast, more grains per panicle and population spikelets (4.8×108/hm2) were observed in super japonica rice,with the same level of seed setting rate and thousand seed weight. The numbers of stems and tillers of super japonica rice grow earlier and faster, and the percentage of productive tillers was higher. The leaf area index and photosynthetic potential of super japonica rice was relatively low before jointing stage, and increased significantly after jointing stage. Compared with the contrast, the grain-leaf ratio of super japonica rice was higher in 3 nitrogen application levels. Compared with the contrast, the dry matter accumulation of super japonica rice was relatively lower before jointing stage, but 7.77% higher at jointing-heading stage, 6.96% higher at heading-maturity stage respectively. The N accu-mulations and N uptake rates of super japonica rice were higher than the contrast at every stage. This study showed that, in 3 nitrogen application levels, the super japonica rice showed obvious advantage to production in Huaibei Area. Compared with the non-super japonica rice, super japonica rice has more grains per panicle and population spikelets. And the leaf area index, photosynthetic poten-tial, grain-leaf ratio, total dry matter accumulation and percentage of productive tillers were high. The reason why the yield of medi-um-maturing medium super japonica rice is higher than the contrast with similar growth period related to its strong characteristics of nitrogen absorption.%为探究淮北地区不同氮肥水平下粳型超级稻产量形成及氮素吸收利用特征。在大田机插条件下，以常规中熟中粳超级稻和非超级稻（对照）为试材，设置3个氮肥水平即0、225、300 kg/hm2。从产量构成因素、干物质和氮素积累、茎蘖动态、叶面积指数等角度分析不同氮肥水平下粳型超级稻产量形成及氮素吸收利用特征。结果表明，随着氮肥施用量的增加超级稻平均产量呈增加趋势，对照产量则是先增加后减少。粳型超级稻最高产量平均值较对照最高产量平均值高10.98%。与对照相比，超级稻在3个氮肥水平下每穗粒数和群体颖花量高，结实率和千粒重与之相当；群体茎蘖移栽后早发快长，最终成穗率高；拔节前叶面积指数和光合势比对照低，拔节后比对照高，超级稻粒叶比在3个氮肥处理下均高于对照；拔节前，超级稻干物质积累量比对照低，而拔节至抽穗、抽穗至成熟阶段干物质积累量分别比对照高7.77%和6.96%；植株氮素阶段积累量和植株阶段吸收速率，移栽至拔节、拔节至抽穗、抽穗至成熟阶段超级稻均比对照高。淮北地区粳型超级稻籽粒产量在3个氮肥处理下均表现出明显的增产优势。超级稻移栽后叶面积指数、粒叶比和光合势较高，最终茎蘖成穗率高；穗型大，群体总颖花量高，穗后干物质积累量多；生育期相近的中熟中粳超级稻产量高于对照与其较强的氮素吸收特性有关。