不同土层测墒补灌对冬小麦耗水特性与光合速率和产量的影响

Effects of supplemental irrigation by measuring moisture content in different soil layers on water consumption characteristics,photosynthesis and grain yield of winter wheat

于2012—2014年两个冬小麦生长季,在大田条件下设置：全生育期不灌水（W0）处理,当地定量节水灌溉（拔节期和开花期均灌水60 mm,W1）处理,依据0-20 cm（W2）、0-40cm（W3）、0-60 cm（W4）和0-140 cm（W5）土层土壤含水量测墒补灌处理,于拔节期和开花期补灌至土壤相对含水量为田间持水量的65%和70%,研究依据不同土层土壤含水量测墒补灌对冬小麦耗水特性、光合速率和籽粒产量的影响.结果表明：各处理拔节期灌水量为W1、W4〉W3〉W2、W5,开花期灌水量和总灌水量均为W5〉W1、W4〉W3〉W2,W3总耗水量显著高于W2处理,与W1、W4和W5处理无显著差异.W3土壤贮水消耗量高于W1、W4和W5处理,其中,W3在拔节至开花阶段和开花至成熟阶段对40-140 cm和60-140 cm土层土壤贮水消耗量均显著高于其余灌水处理.灌浆中期W3处理小麦旗叶光合速率、蒸腾速率和水分利用效率最高,W1和W4处理次之,W0处理最低.W3处理两个生长季的籽粒产量分别为9077和9260kg·hm^-2,水分利用效率分别为20.7和20.9 kg·hm^-2·mm^-1,均显著高于其余处理,灌溉水生产效率最高.综合考虑灌水量、籽粒产量和水分利用效率,小麦拔节期和开花期适宜进行测墒补灌的土层深度为0-40 cm.

Field experiments were conducted during 2012—2014 winter wheat growing seasons. Six irrigation treatments were designed： rainfed,W0; a local irrigation practice that irrigated at jointing and anthesis with 60 mm each time,W1; four irrigation treatments were designed with target relative soil moisture of 65% field capacity（ FC） at jointing and 70% FC at anthesis in 0- 20（ W2）,0- 40（ W3）,0- 60（ W4）,and 0- 140 cm（ W5） soil layers,respectively,to study the effects of supplemental irrigation by measuring moisture content in different soil layers on water consumption characteristics and photosynthesis and grain yield of winter wheat. The irrigation amounts at jointing in W1 and W4were the highest,followed by W3 treatment,W2and W5 were the lowest. The irrigation amounts at anthesis and total irrigation amounts were ranked as W5 W1,W4 W3 W2,the total water consumption in W3 was higher than that in W2,but had no difference with that in W1,W4 and W5treatments,W3 had the higher soil water consumption than W1,W4 and W5treatments,and the soil water consumption in 40- 140 cm soil layers from jointing to anthesis and in 60- 140 cm soil layers from anthesis to maturity in W3 were significantly higher than the other treatments.The photosynthetic rate,transpiration rate and water use efficiency of flag leaf at middle stage of grain filling from the W3 treatment were the highest,followed by the W1 and W4treatments,and W0 treatment was the lowest. In the two growing seasons,the grain yield and water use efficiency in the W3 were 9077- 9260 kg ·hm^- 2and 20. 7- 20. 9 kg · hm^- 2·mm^- 1,respectively,which were higher than those from the other treatments,and the irrigation water productivity in the W3 was the highest. As far as high-yield and high-water use efficiency were concerned in this experiment,the most appropriate soil layer for measuring moisture content was 0- 40 cm.