浅埋式滴灌苜蓿耗水规律和产量对不同灌水定额的响应

Response of water consumption law and yield of alfalfa in shallow embedded drip irrigation to different irrigation quotas

为确定适宜多砾石砂土浅埋式滴灌苜蓿的灌溉制度,试验设定5种灌水定额(22.5、30.0、37.5、45.0和52.5mm)并以地面灌为对照组(CK),研究灌水定额对浅埋式滴灌苜蓿耗水规律和产量的影响。结果表明:不同灌水定额下各茬苜蓿的耗水强度为第2茬>第1茬>第3茬,且均在孕蕾期达到峰值。各茬苜蓿的总耗水量表现为第2茬>第3茬>第1茬,且耗水量分别在分枝期、初花期及孕蕾期最高。灌水定额大于45.0mm时,耗水强度增加趋势不明显且与地面灌(CK)相近。45.0mm灌水定额与地面灌(CK)间的耗水量差异不显著(P<0.05)。高灌水定额(45.0、52.5mm)与地面灌(CK)之间的总耗水量、总产量以及总水分利用效率差异不显著,与低灌水定额(22.5、30.0、37.5mm)差异显著(P<0.05),且各茬苜蓿此三项指标的差异性一致。总产量与总水分利用效率在灌水定额为45.0mm处达到最大,与地面灌(CK)相比分别增加了9.05%、14.54%。选用45.0mm灌水定额和540mm灌溉定额作为多砾石砂土浅埋式滴灌苜蓿灌溉制度较为合适。

To determine the suitable irrigation schedule for alfalfa under shallow embedded drip irrigation in pebbly sandy soil,five irrigation quotas(22.5 mm,30.0 mm,37.5 mm,45.0 mm,and 52.5 mm)were set in the experiment,and the surface irrigation was used as the control group(CK)to study the effect of irrigation quota on the water consumption and yield of shallow embedded drip irrigation alfalfa.The results showed that the water consumption intensity of alfalfa in different stubbles under different irrigation quota was expressed as 2 nd>1 st>3 rd,and all of them reached the peak value in the bud stage.The total water consumption of alfalfa in different stubbles was expressed as 2 nd>3 rd>1 st,and the water consumption was the highest in the branching stage,the initial flowering stage,and the bud stage,respectively.When the irrigation quota was greater than 45.0 mm,the increasing trend of water consumption intensity was smaller and similar to that of surface irrigation(CK).There was no significant difference in water consumption between 45.0 mm irrigation quota and CK(P<0.05).There were no significant differences in total water consumption,total yield and total water use efficiency between high irrigation quota(45.0,52.5 mm)and surface irrigation(CK),but significant difference was found between low irrigation quota(22.5,30.0,37.5 mm)(P<0.05).The total yield and total water use efficiency reached the maximum at the irrigation quota of 45.0 mm,increased by9.05%and 14.54%,respectively compared with the surface irrigation(CK).Therefore,it is suitable to select a 45.0 mm irrigation quota and 540 mm irrigation norm for alfalfa in pebbly sandy soil with a shallow embedded drip irrigation system.