地下水埋深对辽宁中部地区膜下滴灌玉米生长及产量的影响

为探讨地下水埋深对膜下滴灌玉米生长和产量的影响,以沈阳地区为例,选择郑单958玉米品种为试验材料,通过地下水埋深模拟系统设置地下水埋深1.0(D1.0),1.5(D1.5),2.0(D2.0),2.5(D2.5),3.0m(D3.0)共5个处理,对玉米生长指标、灌浆期光合作用、产量及耗水量等指标进行分析。结果表明:(1)不同地下水埋深下的株高、茎粗和叶面积指数达到峰值时的具体表现为D1.0D1.5D2.0D3.0D2.5,且D1.0和D1.5处理下的株高和茎粗达到峰值的日期(播后天数)较其他处理提前了10~20天。(2)D1.0处理下的净光合速率和蒸腾速率较其他处理分别提高18.05%~32.89%和18.50%~137.24%。(3)产量随地下水埋深的增加呈降低趋势,其中D1.0处理产量最大,达17 100kg/hm~2,且产量随着地下水补给和全生育期耗水量的增加而增加。通过对玉米产量影响因素与产量间的通径分析可知,地下水埋深通过增加叶面积指数和穗粒数使玉米增产。浅埋地下水(1.0~2.5m)有助于缩短玉米生育进程,增加叶面积指数,从而提高叶片光合作用能力,促进灌浆期玉米籽粒的形成,增加穗粒数使玉米增产。研究结果可为辽宁中部及类似地区不同地下水埋深条件下玉米高产栽培和节水灌溉提供科学依据。

Effects of Groundwater Depth on Growth and Yield of Maize Under Mulched Drip Irrigation in the Middle Area of Liaoning Province

In order to investigate the effect of groundwater depth on maize growth and yield under mulched drip irrigation, selecting the maize of Zhengdan 958 in the case of Shenyang region as test material, five different groundwater depths of 1.0 (D1.0), 1.5 (D1.5), 2.0 (D2.0), 2.5 (D2.5) and 3.0 m (D3.0) were set up by the simulation system. The growth index, photosynthesis, yield and water consumption of maize were analyzed. The results showed that the specific performance of plant height, stem thickness and leaf area index which reached the peak value under different groundwater depths was D1.0 > D1.5 > D2.0 > D3.0 > D2.5. Besides, D1.0 and D1.5 treatments could shorten time after planting when plant height and stem thickness reached the peak by 10~20 days. Compared with other treatments, the net photosynthetic rates and transpiration rates were increased under D1.0 by 18.05%~32.89% and 18.50%~137.24% respectively. Maize yield decreased with the increasing groundwater depths, and the yield of D1.0 was the largest, reaching 17 100 kg/hm². And maize yield increased with the increasing groundwater recharge and water consumption during the whole growth period. Through the path analysis between maize yield factors and yield,it turned out that groundwater depth improved maize yield by increasing leaf area index and grain numbers. In conclusion, groundwater depth of 1.0~2.5 m could shorten the process of maize growth, increase maize yield by increasing the maize leaf area index, then improve the photosynthesis capacity, promote the formation of maize grain in the filling stage,and finally increase grain numbers. These findings could provide scientific guidance for maize planting and water-saving irrigation under different groundwater depths in the middle area of Liaoning Province.