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作 者 ：孟晓瑜 王朝辉 杨宁 杨荣 章孜亮 赵护兵

期 刊 ：植物营养与肥料学报 2011年 17卷 5期 页码：1083-1090

关键词：磷肥；冬小麦；产量；底墒；水分利用效率；磷肥回收率；

Keywords:phosphorus fertilizer, winter wheat, yield, soil moisture before sowing, water use efficiency, phosphorus recovery efficiency,

摘 要 ：在陕西杨凌渭北旱塬进行5年定位试验，在施N160kg/hm2的基础上，设施P2O5 0、50、100、150 kg/hm2 4个施磷水平，结合5年降水情况，分析了播前底墒、施磷对旱地冬小麦产量及水肥利用的影响。结果表明，夏季7～9月的降水是决定渭北旱塬小麦播前底墒的关键因素，两者呈线性相关夏季每增加1 mm降水，土壤贮水增加0.5mm。要保持这一地区小麦稳产或高产，底墒应保持550 mm左右，夏季降水应有380 mm左右。夏季降水充足的年份，施磷量增加造成的下季小麦播前底墒下降不明显；降水偏少的（<350mm）的年份，合理施磷能够促进小麦生长，导致生育期内对土壤水分消耗较多，降低土壤含水量，使前季小麦每增施磷50 kg/hm2，下季小麦播前底墒减少9～12 mm。除底墒外，关键生育期的充足降水也是保证旱地小麦产量重要因素，每毫米播前底墒能形成9.0～9.9 kg/hm2、生育期降水形成28.6～33.3 kg/hm2小麦子粒产量。施磷水平决定了作物生物量、产量高低；底墒决定了水分和磷肥利用的程度或水平，同时水分也制约着作物累积的干物质向收获器官（子粒）转移的多少或比例。在底墒充足的年份，较低的施磷量，就可实现较高的产量和水肥利用效率；底墒较差的年份，则要求较高的磷肥投入量。

Abstract:Research of soil moisture before sowing(SMBS) and phosphorus fertilization on Weibei Plain is recognized to be of great significance for optimizing soil water and fertilizer management of wheat and achieving high crop yield and efficiency in rainfed areas. A five-year long allocation experiment was carried out to study the effects of soil moisture before sowing and phosphorus fertilization on the yield and water and fertilizer use efficiencies of winter wheat in Weibei tableland of Yangling, Shannxi, China. There were 4 phosphorus rates, P2O50, 50, 100 and 150 kg /ha on the basis of N 160 kg /ha. The results show that precipitation from July to September in summer is the key factor to decide SMBS on Weibei tableland, and they are linearly and positively correlated with 1 mm summer precipitation leading to an increase of 0.5 mm SMBS. For a stable or high wheat yield, the SMBS should be kept around 550 mm and summer precipitation around 380 mm. In years with adequate summer precipitation, the SMBS is not obviously decreased by the increased P fertilizer application in the previous winter wheat growing season. However, reasonable P application promotes the growth of winter wheat, and lead to more consumption of soil moisture during the growing season, then reduced soil moisture, and it is significantly decreased by 9–12 mm when the P2O5 rates is increased by each P2O5 50 kg /ha in the previous growing season in the years with little summer precipitation (less than 350 mm). In addition to soil moisture before sowing, adequate precipitation in the key growth stages is another important factor to ensure wheat yield in the areas. Calculation based on this experiment indicates that one mm of SMBS could produce 9.0–9.9 kg/ha of wheat grain, and one mm precipitation occurred in the key growth stages could lead to more grain yield as high as 28.6–33.3 kg/ha. Meanwhile, SMBS restricts the allocation and transportation of dry matter from vegetative parts to grain. For a higher winter wheat yield and water and fertilizer use efficiencies in the area, less P fertilizer is needed in the years with adequate SMBS, while more P fertilizer is needed when the SMBS is deficient.

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