关中灌区沟垄集雨种植补灌对冬小麦光合特征、产量及水分利用效率的影响

Effects of ridge and furrow rain harvesting with supplemental irrigation on winter wheat photosynthetic characteristics,yield and water use efficiency in Guanzhong irrigation district

通过大田试验,研究了沟垄集雨种植结合不同补灌量处理对冬小麦光合器官、光合速率、产量和水分利用效率的影响.结果表明：沟垄宽度各为60 cm时,集雨种植不灌溉（T1）、返青期种植沟补灌375 m3·hm-2（T2）和种植沟补灌750 m3·hm-2（T3）3个处理较平作灌水750 m3·hm-2（畦灌,T4）处理的小麦籽粒产量分别提高2.8%、9.6%和18.9%,收获系数提高2.0%~8.5%,旗叶叶绿素含量提高41.9%~64.4%,整个生育期内0~40 cm土壤含水量增加了0.1%~4.6%;开花期和灌浆期的叶片光合速率分别较T4处理提高了22.3%~54.2%和-4.3%~67.2%,农田总水分利用效率较T4处理分别提高17.9%、10.4%和15.4%,比平作不灌水处理（CK）提高69.3%、58.6%和65.7%;降水利用效率较CK提高94.3%~124.5%;T2、T3处理各生育阶段叶面积均显著高于T4处理,灌溉水利用效率分别比T4处理提高119.1%和18.8%.在灌溉量减少50%的条件下,集雨种植比畦灌处理能维持较高的籽粒产量,显著提高灌溉水利用效率,尤其是在降雨量偏少的年份,可以显著提高小麦水分利用效率.

A field experiment was conducted to determine the regulation of crop photosynthesis and output and water saving effect under ridge and furrow rain harvesting with supplemental irrigation in Guanzhong irrigation district. The experiment was set with 5 treatments with irrigation at returning green stage,and the widths of both ridge and furrow being 60 cm. T1,T2 and T3were in the ridge and furrow rain harvesting planting pattern,with the irrigation volumes being 0,375 and 750m3·hm-2respectively,T4 was flat planting with irrigation（ border irrigation） of 750 m3·hm-2and CK was flat planting without irrigation. Effects on winter wheat photosynthetic organs,photosynthetic rate,yield and water use efficiency,etc. were tested. The results showed that compared with T4,T1,T2 and T3treatments increased the grain yield by 2. 8%,9. 6% and 18. 9%,improved the harvest index by 2. 0% to 8. 5%,advanced the flag leaf chlorophyll content by 41. 9% to 64. 4% significantly,and improved the 0-40 cm layer soil moisture content by 0. 1%-4. 6% during the whole growth period. Photosynthetic rates at the flowering and filling stages also increased by 22. 3% to54. 2% and-4. 3% to 67. 2%,respectively. Total water use efficiencies（ WUEy） were 17. 9%,10. 4% and 15. 4% higher than that of T4,and 69. 3%,58. 6% and 65. 7% higher than that of CK（ P〈0. 05）, respectively, and enhanced precipitation utilization efficiency（ PUE） by94. 3%-124. 5% than CK. Leaf areas of T2 and T3treatments at each growth stage were significantly higher than that of T4 and CK,irrigation water use efficiencies（ IUE） were 119. 1% and 18. 8%higher than that of T4,respectively. Therefore,it was concluded that ridge and furrow rain harvesting cultivation could maintain higher grain yield than border irrigation without irrigation or with irrigation reduction by 50%. The utilization efficiency of irrigation water under the condition of irrigation reduction by 50% was improved significantly,and the ridge and furrow rain harvesting could significantly improve whole cropland water use efficiency in the year of less rainfall.