不同水分条件下冬小麦浅层地下水利用试验研究

使用蒸渗仪群开展了冬小麦对浅层地下水利用试验,讨论了在降雨、灌溉和不同地下水埋深等多种水分条件下冬小麦对浅层地下水的利用规律,并确定了适宜冬小麦生长的地下水埋深上限和相应的合理灌水量。结果表明,从返青至收获期,在40~150 cm埋深范围内,无灌溉无降雨条件下地下水对作物腾发的贡献率可达到90.0%以上,而降雨和灌溉处理的地下水贡献率减小到54.0%~78.9%。另外,无论是否有降雨影响,随着地下水埋深的增加,地下水贡献率都降低。试验结果还表明,150 cm是适宜冬小麦生长的地下水埋深上限,每公顷穗数较大是冬小麦产量高于其他埋深处理的主要原因。从返青至灌浆期,在150 cm埋深下,只需在拔节期灌水约60.0 mm,冬小麦产量就可达到8 846 kg/hm2,在无灌水和降雨时产量可达到拔节灌溉处理的80.0%左右。

Experimental Research on the Uptake of Shallow Ground Water by Winter Wheat under Different Water Conditions

Based on the data measured by lysimeter group,considering the influence of the multi-factors such as ground water depth,precipitation and irrigation,the rule of the uptake of shallow ground water by winter wheat was discussed.In addition,the upper limit of the proper groundwater depth for winter wheat growth and the corresponding irrigation amount were determined.The results showed that the contribution rates of ground water to evapotranspiration decreased due to irrigation and precipitation.When ground water depth was in the range from 40 to 150 cm,the contribution rates for the treats without precipitation and irrigation would be more than 90.0% from green to harvest stage.As comparisons,the rates descende from 54.0% to 78.9% for the treats with precipitation and irrigation.Whether there was precipitation or not,the ground water contribution rates decreased with the increase of ground water depth.Moreover,the 150 cm treats had the highest yields due to the highest values of ears,and then 150 cm was determined as the upper limit of the proper ground water depth for winter wheat.For this depth,the yield of winter wheat with 60.0 mm irrigation amount in elongation stage reached 8 846 kg/hm2,and for the treat without irrigation and precipitation,the yield could be approximately 80.0% of that of the treat with irrigation during elongation.