不同施磷水平对旱地小麦产量及其构成要素的影响

Impact of Different Phosphorus Application Levels on Yield and Grain Traits of Winter Wheat in Drylands

【目的】探索旱地小麦适宜施磷量。【方法】于2012—2014年在山西农业大学闻喜县邱家岭村开展大田试验,设置了施磷量(P2O5)分别为0、75、150、225 kg/hm^2共4个处理,分析了磷肥对旱地小麦土壤水分、土壤和植株含磷量、产量及其构成的影响。【结果】随施磷量的增加,花前0~300 cm土壤蓄水量、拔节后表层土壤有效磷量、各生育时期植株磷素积累量均呈先升后降的变化趋势,以施磷量150 kg/hm^2最高。2012—2013年度和2013—2014年度施磷量均为150 kg/hm^2时,产量及其构成要素最高(与拟合方程结果一致,2个试验年度施磷量分别为153、148 kg/hm^2增产效果较好),各农艺性状均有提高,穗数增幅为9%~18%和14%~22%,穗粒数增幅为5%和5%,千粒质量增幅为4%~6%和8%~12%,产量增幅为21%~41%和19%~24%,水分利用效率增幅为19%~25%和17%~20%。相关分析表明,降水年份对穗数、穗粒数、千粒质量具有显著或极显著调控作用,磷肥对产量构成因素的影响均不明显,降水年份和磷肥之间的交互作用对穗数、穗粒数具有显著或极显著影响,降水年份对产量的调控作用大于磷肥;穗数、千粒质量与产量极显著正相关。【结论】施磷量为150 kg/hm^2时,有利于旱地麦田保持土壤水分,提高土壤表层有效磷量和植株磷素积累量,从而优化了产量构成要素,最终提高了籽粒产量、水分利用效率和磷肥贡献率。

【Objective】Fertilization is essential in modern agriculture but inappropriate management could lead to yield decrease rather than increase. We took phosphorus fertilizer as an example in this paper, investigating the impact of its application levels on yield and grain traits of wheat growing in dryland in the Loess Plateau.【Method】A field experiment was conducted from 2012 to 2014 at the Village of Qiujialing at Wenxi County of Shanxi Province, with phosphorus fertilizer applied at 0, 75, 150 and 225 kg/hm2 respectively. During the experiment, we measured soil moisture, accumulation of phosphorus in both soil and plant, as well as the yield and grain traits of the wheat.【Result】With the increase in phosphorus application, the 0-300 cm water content before flowering stage, the available phosphorus in top soil after jointing stage, and the accumulated phosphorus at each growth stage all increased first, followed by a decline after peaking at 150 kg/hm2. The regression model between yield and phosphorous application rate gave a maximum yield of 153 kg/hm2 in 2012—2013 and of 148 kg/hm2 in 2013—2014. With phosphorus application increasing, the number of spikes increased by 9%-18% and 14%-22%, the grains per spike by 5%, 1000-grain weight by 4%-6% and 8%-12%, yield by 21%-41% and 19%-24%, and water use efficiency by 19%-25% and 17%-20%, respectively, in 2012—2013 and 2013—2014. Correlation analysis showed that precipitation affected the number of spikes, the number of grains per spike and 1000-grain weight more significantly than the phosphorus fertilizer did, and that precipitation and phosphorous combined to regulate the number of spikes and the number of the grains per spike. We also found that precipitation had a more profound impact on the yield than phosphorus.【Conclusion】Applying phosphorus fertilizer at 150 kg/hm2 appeared to be optimal. It enhanced soil moisture, the available phosphorus in top soil, as well as phosphorus accumulation in plant, thereby increasing water use efficiency, yield and grain traits.