杂交中稻在不同地域和施氮水平下氮素吸收利用效率的变异(英文)

Variation of Nitrogen Uptake and Utilization Efficiency of Mid-Season Hybrid Rice at Different Ecological Sites under Different Nitrogen Application Levels

[目的]为了探明氮素在植株中的积累与分配状况及氮素吸收利用率与试验点的地理位置、土壤化学特性、施氮量的关系。[方法]2009年以杂交中稻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。[结果]稻谷产量在地点间、品种间、施氮量间、地点与品种互作效应、地点与施氮量互作效应均达极显著水平,而品种与施氮量间的互作不显著;成熟期地上部干物重、含氮率和氮肥吸收利用效率分别在试验点、品种间和施氮量间的差异达极显著水平。氮素吸收率与利用率呈极显著负相关;氮素吸收利用率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,F值9.34＊＊ ~914.30＊＊,决定系数高达0.705 2 ~0.999 8。[结论]施氮量越高,氮肥的利用效率越低;土化特性对氮吸收利用率的影响因品种和具体的氮利用率指标而异,氮稻谷生产率与土壤有机质含量呈极显著正相关,经度、海拔越高,氮肥利用效率越高。

[Objective] The study aimed at investigating the effects of different geographic sites,soil chemical characteristics and nitrogen application levels on nitrogen accumulation and distribution in different organs and utilization efficiency for mid-season hybrid rice.[Method] By using mid-season rice varieties II-you 7 and Yuxiangyou203 as the experimental materials,field experiment was conducted at seven ecological sites in four provinces or cities in Southwestern China in 2009.A total of four nitrogen application levels were set as follows：by using 75 kg/hm2 of P2O5 and 75 kg/hm2 of K2O as the base fertilizer,extra 0,90,150 and 210 kg/hm2 of nitrogen fertilizer（in which,base fertilizer,base-tillering fertilizer and base-earing fertilizer respectively accounted for 60%,20% and 20%.） was applied,respectively.In the split-plot design,fertilizer was considered as the main factor while rice variety was taken as the secondary factor.A total of eight treatments were set with three replications.[Result] Highly significant differences of grain yield were found among seven locations,two varieties,four nitrogen application levels,interactions of site × variety and site × nitrogen application level,but the interaction of variety ×nitrogen application level had no significant influence on rice yield.There were highly significant effects of site,varieties and nitrogen application level on dry matter production,nitrogen content,nitrogen utilization efficiency.Highly significant negative correlations between uptake efficiency and utilization efficiency for nitrogen were found;and multiple stepwise regression analysis showed that nitrogen uptake-utilization efficiency were significantly influenced by different ecological sites,chemical quality of soil and the levels of nitrogen application.[Conclusion] The research will provide theoretical and practical basis for the highly efficient application of nitrogen in mid-season hybrid rice cultivation.