不同降水年型和施磷水平对小麦产量的效应

Effect of Precipitation Patterns and Different Phosphorus Nutrition Levels on Winter Wheat Yield

【目的】水肥是黄土旱塬小麦产量提高的两大限制因子。探讨长期定位施肥下不同降水年型和施磷水平对黄土高原旱作小麦产量效应,可为不同降水年型下合理施用磷肥和提高旱塬小麦产量提供理论依据。【方法】以黄土高原30年长期磷肥定位试验为基础,并将冬小麦生育年降水划分为干旱年型、平水年型和丰水年型,深入分析不同降水年型和施磷水平对小麦产量、产量构成因素及磷肥贡献率的影响。【结果】干旱年型下各处理的小麦产量、千粒重、穗粒数、公顷有效穗数与平水年型相比呈降低趋势,丰水年型下则呈增加趋势;与平水年型相比,干旱年型的肥料贡献率呈增加趋势,丰水年型的肥料贡献率呈降低趋势;干旱年型、平水年型、丰水年型以及30年均值中,随施磷水平的提高,小麦产量、千粒重、穗粒数呈现出先增后降的趋势;公顷有效穗数在干旱年型呈现先增后降的趋势,平水年型、丰水年型和30年均值中呈直线上升变化;磷肥贡献率在干旱年型呈现先增后降的趋势,平水年型呈现直线上升变化,丰水年型呈现直线下降变化。进一步对各处理的产量与产量构成因素相关分析可知,不同降水年型和施磷水平处理主要通过调控公顷有效穗数进而影响小麦产量,公顷有效穗数与干旱年型、平水年型、丰水年型和连续种植30年产量的偏回归系数分别为0.713、0.294、0.692和0.643。【结论】不同降水年型和施磷水平对小麦产量具有显著调控效应,不同降水年型下施磷水平在125—137 kg·hm^(-2)时小麦增产效果较好,且以连续种植30年施磷131 kg·hm^(-2)处理的增产效果最佳;降水年型和施磷水平主要通过调控小麦产量构成三因素中的公顷有效穗数而影响小麦产量。

【Objective】Water and fertilisation are the main two factors limiting wheat production in arid and semiarid regions of the Loess Plateau. The effects of precipitation patterns and phosphorus nutrition levels on wheat yield under long-term fertilizer field experiment were studied. The result will provide a theoretical basis for improving wheat yield with a reasonable phosphorus level with different precipitation patterns in the semiarid regions.【Method】Growth years precipitation were divided into dry years, normal years and wet years based on 30 years long-term fertilizer field experiment on the semiarid Loess Plateau in China. Effects of precipitation patterns and phosphorus nutrition levels on the winter wheat yield, yield component and phosphorus contribution rate （PCR） were deeply studied on the semiarid Loess Plateau.【Result】Wheat yield, 1000-grain weight, grains per spike and spike numbers in the dry years were lower than the normal years, higher in the wet years than the normal years. pCR in the dry years was higher than the normal years, lower in the wet years than the normal years. Wheat yield, 1000-grain weight and grains per spike in the dry, normal, wet and 30 years planting showed a trend of increase first and fall later with the adding of phosphorus. Spike numbers were increased first and fall later in the dry years, presented a rise perpendicularly in the normal years, wet years and 30 years planting. PCR was increased first and fall later in the dry years, presented a rise perpendicularly in the normal years, linear decrease in the wet years. The correlation coefficient between the yield and yield components showed that different precipitation patterns mainly through affecting the spike numbers to influence the yield. The partial regression coefficient among spike numbers and dry, normal, wet years and 30 years planting was 0.713, 0.294, 0.692 and 0.643, respectively.【Conclusion】Phosphorus nutrition levels and precipitation patterns could significantly impact the wheat yield. The yield in the 125-137 kg·hm-2 phosphorus treatment was the best in different precipitation patterns. The yield in the 131 kg·hm^-2 phosphorus treatment was the best with the 30 years continuous planting. Precipitation patterns and phosphorus nutrition levels mainly through regulating the spike numbers of wheat yield components to influence the yields.