微咸水灌溉下土壤水盐动态及对作物产量的影响

Effect of slight saline water irrigation on soil salinity and yield of crop

华北平原农业灌溉用水非常紧缺,水资源日益缺乏与粮食需求日益增多之间的矛盾尖锐。充分利用微咸水资源是缓解这一矛盾的重要途径之一。该文以中国农业大学曲周试验站1997-2005年冬小麦和夏玉米微咸水灌溉田间长期定位试验为基础,研究了充分淡水、充分淡咸水、关键期淡水、关键期淡咸水和不灌溉等5个处理下土壤饱和电导率和含盐量的动态变化,探讨了微咸水灌溉对冬小麦和夏玉米产量的影响。结果表明:土壤水盐动态呈受灌溉和降雨影响的短期波动和受季节更替影响的长期波动;在正常降雨年份,使用微咸水进行灌溉是可行的,不会导致土壤的次生盐渍化;微咸水灌溉虽然导致冬小麦和夏玉米产量降低10%～15%,但节约淡水资源60%～75%。如果降雨量达到多年平均水平以及微咸水灌溉制度制订合理,微咸水用于冬小麦/玉米田间灌溉前景广阔。

Irrigation water for agricultural use is severe shortage in North China Plain.The conflict between water resources lacking and food demand increasing is increasingly sharp.Using slightly saline water resources is one of the important ways to alleviate the conflict.Based on the experiment which focuses on the effect of slightly saline water irrigation on soil salinity and yield of winter wheat and summer maize in Quzhou Experimental Station of China Agricultural University from 1997 to 2005,five treatments（fully irrigated with fresh water,economically irrigated with fresh water,fully irrigated with fresh-saline water,economically irrigated with fresh-saline water and control,i.e.,no irrigation）was designed,dynamics of saturated soil electrical conductivity and salt contents under slightly saline water irrigation were studied,and the effects of slightly saline water irrigation on yield of winter wheat and maize were discussed.The results showed that soil water and salinity turn on the short-term and long-term fluctuations which are affected by amounts of irrigation and rainfall and changes of seasons;Generally,it was feasible to irrigate with saline water in field that it would not cause salinization;Compared with the treatment of fully irrigated with fresh,yield of winter wheat and maize decreased by 10%-15%and fresh water saved 60%-75%under the treatment of fully irrigated with fresh-saline water.If rainfall reaches to the normal level and saline water irrigation schedule is rational,the utilization of saline water for winter wheat and maize could be prospective for the sustainable agriculture.