中文摘要：

为明确磷肥在旱地小麦生产上的作用及最佳磷肥施用技术,于山西闻喜县进行了3个施磷量（P2O5用量75、112.5、150kg/hm2）条件下2个施磷深度（20cm、40cm）的田间试验,研究了其对土壤水分、根系分布及产量的影响。结果表明,增加施磷量,孕穗期20-80cm根长密度提高,且深层施磷效果显著。增加施磷量,越冬—孕穗期0-100cm土壤蓄水量显著提高,且深层施磷效果更好,尤其生育中期深层土壤水分。增加施磷量,成熟期穗数显著提高,千粒质量增加,且深层施磷穗数和穗粒数处理间差异显著。增加施磷量,产量提高528-736kg/hm2,水分利用效率提高26%-29%,且深层施高磷显著提高了产量、水分利用效率和经济系数。结果还表明,深层施高磷的节水、增产效果最好。此外,深施磷肥条件下,穗数与越冬、返青和孕穗期20-40cm,拔节期60-80cm土层蓄水量关系密切;穗粒数与拔节和孕穗期40-60cm土层关系密切;产量与越冬—孕穗期20-100cm土层关系密切,尤其与越冬和孕穗期20-40cm、拔节期60-80cm土层。总之,旱地小麦增加施磷量有利于增加深层根系分布,进而提高花前1m土体内土壤水分,且深层施磷效果显著;深层施磷主要通过提高穗数和穗粒数实现节水增产,且以配施150kg/hm2磷肥效果最好。

英文摘要：

In order to find out the role of phosphorus（P）in the dryland wheat production and the best application techniques of phosphorus fertilizer,a field test was carried out in Wenxi,Shanxi province,in which the phosphorus application was divided into 3levels（P2O575kg/hm2,112.5kg/hm2,150kg/hm2）and the application depth was divided into 2levels（20cm,40cm）to study the effect of deep application of phosphorus fertilizer on soil moisture,root distribution and grain yield of dryland wheat.The results indicated that：Increasing the amount of P,root length density at the depth of 20-80cm at booting stage increased,and the effect of deep P was significant.Increasing the amount of P,soil moisture at the depth of0-100cm from wintering stage to booting stage was significantly improved.The effect of deep P application was better,which especially improved the mid-deep soil moisture at middle growth period.Increasing the amount of P,spike number was improved significantly at maturity stages.1 000-grain weight was also increased.Deep P application improved spike number and grain number per spike significantly.Increasing the amount of P,grain yield increased by 528-736kg/hm2 and water use efficiency increased by 26%-29%.Deep application of high P improved grain yield,water use efficiency and economic coefficient notably.The results also showed that deep application of high P had the best effects of water-saving and yield promotion.In addition,under the condition of deep application of phosphorus fertilizer,the relationship between spike number and the soil water storage at the depth of 20-40cm layer of wintering stage,turning green stage and booting stage was close.The relationship between spike number and 60-80cm of soil water storage of elongation stage was close.The relationship between grain number per spike and the soil water storage at the depth of 40-60cm of elongation stage and booting stage was close.The relationship between grain yield and the soil water storage at the depth of 20-100cm layer from wintering stag