不同施磷水平下灌水量对小麦水分利用特征及产量的影响

采用大田试验,设灌水和施磷2个因素,其中灌水设W0(不灌水)、W1(拔节水60mm)、W2(拔节水+开花水,每次灌水60mm)、W3(拔节水+开花水+灌浆水,每次灌水60mm)共4个水平;磷肥设P1(90kg/hm2)和P2(180kg/hm2)2个水平,研究不同施磷水平下灌水量对小麦耗水特征、旗叶水分生理特性及产量的影响。结果表明:同一施磷水平下,随灌水量的增加,灌水量占总耗水量的比例增大,而降水量和土壤供水量所占总耗水量的比例下降,且土壤供水量占总耗水量的比例降低幅度增大。与P1相比,P2处理的0-100cm土壤贮水消耗量显著大于P1处理,并且P2处理提高土壤供水量占总耗水量的比例,说明增施磷肥可提高小麦对土壤水的利用。W2和W3处理灌浆中后期旗叶相对含水量和水势高于W0和W1处理;灌浆后期旗叶相对含水量和水势为P2W0和P2W1处理显著分别高于P1W0和P1W1处理,说明增加灌水和磷肥能显著提高旗叶水势和相对含水量。在本试验条件下,施磷90kg/hm2、拔节水和开花水分别灌60mm的W2处理籽粒产量、水分和磷素利用效率高,农田耗水量较低;增加灌水量后籽粒产量无显著变化,农田耗水量增高,土壤贮水消耗量、水分利用效率、灌溉水利用效率均降低。

Effects of Irrigation Amount on Water Use Characteristics and Grain Yield of Wheat Under Different Phosphorus Application Rates

A field experiment was conducted to examine the effects of irrigation amount on the water consumption,flag leaf physiological characteristics,and grain yield of wheat under the phosphorus application rates 90 kg/hm2(P1) and 180 kg/hm2(P2).Four irrigation amounts were set with no irrigation during whole growth period(W0),irrigation with 60 mm water at jointing stage(W1),irrigation with 60 mm water at jointing and anthesis stage(W2),irrigation with 60 mm water at jointing and anthesis and filling stage(W3),respectively.The results indicated that under the same phosphorus rates,with increasing irrigation,water consumption amount increased,but the ratio of precipitation amount and soil water amount to water consumption amount reduced significantly.Compared with the P1 treatment,P2 treatment soil water consumption of 0-100 cm was significantly higher than that of P1 treatment,and also improved the proportion of soil water consumption for total water consumption,it indicated that addition phosphorus fertilizer could improve the use of soil water of winter wheat.At mid and late grain-filling stages,the relative water content(RWC) and water potential(ψw) of flag leaves were higher in treatments W2 and W3 than in treatments W0 and W1.The RWC and ψw at late grain-filling stage were higher in treatments P2W0 and P2W1 than in treatments P1W0 and P1W1,respectively.Based on these results,it is concluded that treatment with phosphorus application at P2O5 90 kg/hm2,irrigation at 120 mm could get high grain yield and water use efficiency(WUE),and phosphorus use efficiency,while over-irrigation increased the water consumption amount,and decreased the WUE,irrigation water use efficiency(WUEI),and the soil storage water consumption.