精确定量施肥对贵州高原山区杂交籼稻产量与群体质量的影响

【目的】水稻产量在很大程度上受环境、栽培技术等多种因素的影响。根据各地的气候特点有针对性地采用栽培技术，可以充分挖掘水稻产量潜力，大幅度提高单产。论文旨在探明精确定量施肥对贵州高原山区杂交籼稻群体质量及产量形成的影响效应。【方法】于2010—2011年在贵州省黄平、绥阳、余庆、兴义4个不同生态稻区，以当地具有高产潜力的杂交籼稻品种为试材，设计精确定量施肥模式（accurate fertilizer，AF）与常规施肥模式（conventional fertilizer，CF），通过对两种施肥模式的比较，研究不同施肥模式的群体质量及产量形成的差异。精确定量施肥模式以斯坦福（Stanford）方程为基础，根据目标产量需氮量、土壤供氮量及氮肥当季利用率计算总施氮量，各阶段的施肥量根据目标产量的阶段需氮量确定。精确施肥模式的总氮按照基肥﹕分蘖肥﹕促花肥﹕保花肥为30%﹕20%﹕35%﹕15%施用，常规施肥模式氮素总量按基肥﹕分蘖肥﹕促保花肥为20%﹕60%﹕20%施用。在有效分蘖临界叶龄期、拔节期、抽穗期、成熟期分别取地上部分测定叶面积和干物质量，成熟期考查穗数、穗粒数、结实率和千粒重。【结果】精确定量施肥模式显著提高了黄平、绥阳、余庆、兴义4个点的水稻产量，增产幅度为12.4%—48.0%，从产量构成因素看，穗数和穗粒数均较常规施肥模式有不同程度提高，穗数增加8.1%以上，穗粒数增加2.5%以上，群体颖花量增加14.3%以上，而结实率和千粒重两种施肥模式的差异较小；比较分析两种施肥模式的穗型大小，精确定量施肥模式较常规施肥模式穗粒数小于100粒的小穗比例降低、100—250粒的大穗和250粒以上的特大穗比例增加，小穗比例减少了36.7%—100%，大穗比例提高了2.2%—11.4%，特大穗比例提高了23.3%—94.9%；在叶面积指数与粒叶比方面；精确定量施肥模式比常规施肥模式的群体叶面积指数拔节前有所降低（4.2%—11.8%）、抽穗期显著提高（4.2%—13.9%）；粒叶比明显增大，其中颖花/叶为9.3%—32.7%、实粒/叶为12.8%—35.7%、粒重/叶为10.1%—36.3%；干物质积累量表现为精确定量施肥模式比常规施肥模式拔节前有所降低，拔节至抽穗期提高了9.8%—50.8%，抽穗至成熟期提高了26.9%—62.7%。【结论】精确定量施肥模式显著提高了贵州杂交籼稻产量，其途径主要通过控制拔节前的群体生长，促进拔节后的群体发展，适度减小拔节前群体叶面积和干物质积累，扩大拔节后尤其是抽穗后群体叶面积和干物质积累，在稳定提高穗数的基础上，控制晚生小穗数量、促进大穗形成，提高穗粒数和粒叶比，实现抽穗后群体干物质的高积累，从而获得高产。

Effects of Accurate Fertilizer Model (AF) on Yield and Population Quality of Hybrid Indica Rice Cultivars in Guizhou Highland Area

【Objective】Rice yield is largely affected by many factors including environment and cultivation. Therefore, targeted use of cultivation techniques according to the climate characteristics can fully exploit the potential of rice yield and improve grain yield significantly. Experiments were conducted to study the effects of accurate fertilizer model (AF) on population quality and yield formation of hybrid indica rice cultivars in high mountain area. 【Method】 Field experiments were conducted in several rice growing areas(Huangping, Suiyang, Yuqing, Xingyi) of Guizhou province in 2010 and 2011. The local high-yielding potential hybrid indica cultivars were separately grown in every rice area, and the population quality and yield formation were studied through the comparison of accurate fertilizer model (AF) and conventional fertilizer model (CF). AF was designed based on Stanford equation, calculate the total N-fertilizer application based on three parameters including the nitrogen demand for the designed grain yield, nitrogen provided by soil, and N-fertilizer use efficiency(NUE). And the nitrogen applied at different growth stages were determined by nitrogen demand of corresponding stage. The total N fertilizer amount was divided into four sections and was applied 1 day before transplanting (30%), 7 days after transplanting (20%), panicle ignition (35%) and at the 2nd leaf from top stretching (15%), respectively. The total nitrogen application amount was identical for the two nitrogen ferltilizer models, and for the CF, nitrogen was applied 1 day before transplanting (20%), 7 days after transplanting (60%), panicle ignition (20%), respectively. Leaf area index (LAI) and dry matter production were measured at N-n, elongation, heading and maturity. Productive panicles, spikelets per panicle, filled grain ratio, grain weight were also measured at maturity.【Result】Compared with CF, AF increased average grain yield of rice by12.4%-48.0% in Huangping, Suiyang, Yuqing and Xingyi, spikelets per panicle increased by over 8.1%, seed-setting rate increased by over 2.5%, population spikelets amount increased by over 14.3%, but seed setting rate and 1000-grain weight was changed insignificantly. Judging from the panicle size, the percentage of small panicle (spikelets per panicle from 0 to 100) decreased by 36.7%-100%, the percentage of big panicle (spikelets per panicle from 100 to 250) increased by 2.2%-11.4%, and huge panicle (spikelets per panicle above 250) increased by 23.3%-94.9%. As for leaf area index (LAI), LAI at elongation stage of the AF rice was 4.2%-11.8% lower in comparison with CF rice. The LAI at heading stage increased by 4.2%-13.9% when LAI of top three leaves and spiklets per leaf area (total spikelets per leaf area, filled grain per leaf area, grain weight per leaf area) of AF rice compared with CF rice. The ratio of spikelet to leaf increased by 9.3%-132.7%, the ratio of grain to leaf increased by 12.8%-35.7%, and the ratio of grain weight to leaf increased by 10.1%-36.3%. The dry matter accumulation decreased at elongation, and increased by 9.8%-50.8% during the period from elongation to heading, and increased by 26.9%-62.7% during the period from heading to maturity.【Conclusion】 The AF management can increase the hybrid rice yield significantly, resulting from controlling the population growth before jointing, promoting group development after jointing, especially increasing LAI and dry matter accumulation in the period from heading to maturity, also including decreasing small panicle formation and developing large panicle.