西南稻区不同地域和施氮水平对杂交中稻氮、磷、钾吸收累积的影响

以杂交中稻II优7号和渝香优203为材料，在西南稻区4省(市)的7个生态点采用相同的试验方案，研究了地理位置、土化特性、施氮量对植株氮、磷、钾积累和分配的影响。结果表明，不同试验地点间稻谷产量、干物质产量、氮磷钾的吸收量、收获指数和每生产1 000 kg稻谷的氮、磷、钾需要量(RAGPPG)差异显著或极显著。施肥处理对稻谷产量、干物质产量、氮的吸收量、收获指数和RAGPPG中的氮有显著或极显著影响，对RAGPPG中的磷、钾影响不显著。氮、磷、钾收获指数间和RAGPPG间均呈极显著正相关，RAGPPG和收获指数均与稻谷产量水平没有相关性。经逐步回归分析，RAGPPG和氮、磷、钾收获指数均分别与试验点所处地理位置、施肥水平及土化特性呈极显著线性关系，决定系数分别为0.5972~0.8404和0.7637~0.8804。可作为制定各地水稻高产高效相应的氮、磷、钾施肥量的科学依据。

Characteristics of Nutrient Uptake and Utilization of Mid-season Hybrid Rice under Different Nitrogen Application Rates in Different Locations of Southwest China

The characteristics of nitrogen (N), phosphorus (P) and potassium (K) uptake and their utilization of mid-season hybrid rice were studied. Field experiment were conducted with mid-season rice combinations II-you 7 and Yuxiangyou 203 grown under the condition of different ecological sites, chemical qualities of soil and the levels of N application in 2009. By using variance, correlation, regression and partial correlation analysis, the results indicated that significant or highly significant differences of grain yield, dry matter production, uptake amount and harvest indexes of N, P, K and N, P, K requirements of above ground plants for producing of 1 000 kg grains (RAGPPG) were found among seven locations. There were significant or highly significant effects of fertilizer application treatments on grain yield, dry matter production, uptake amount, harvest index and N among RAGPPG, but no effect on P and K among RAGPPG. Highly significantly positive correlations were observed among harvest indexes of N, P, K and among RAGPPG, but not between harvest indexes of N, P, K; RAGPPG and grain yield. Multiple stepwise regression analysis showed that harvest indexes of N, P, K and RAGPPG were significantly influenced by different ecological sites, chemical qualities of soil and the levels of N application, and the determination coefficients ranged from 0.5972–0.8404 and 0.7637–0.8804。The results provide a scientific basis for the determination of the efficient amount of N, P, and K applied for full scale rice cultivation.