华北平原微咸水灌溉下土壤盐分淋洗规律与灌溉策略

Irrigating strategy and leaching discipline of slightly saline water in North China Plain

合理有效利用微咸水是华北平原农业水资源短缺的重要缓解途径。基于多年试验站数据对土壤盐分动态类型、盐分淋洗条件及淋洗需水量进行了分析,并探讨了华北平原微咸水灌溉策略。结果表明:土壤盐动态淋滤型可以细分为充分淋洗型和不充分淋洗型;在华北平原冬小麦和玉米轮作制度下,只要保持土壤饱和电导率低于6 dS/m,土壤就处于完全淋洗状态;根据稳定状态盐量平衡法计算得到华北平原实验站冬小麦生育期内淋洗所需咸水量为368mm,夏玉米生育期内淋洗所需咸水量为327mm;从提高作物抗盐分胁迫和渗透胁迫能力的角度,建议在盐渍化土壤上种植较耐盐的作物;从降低土壤盐分含量的角度,可以采用提高灌溉频率、改变灌溉方法、额外灌溉进行淋洗、播种前进行灌溉淋洗盐分、用有机或无机物料对土壤进行处理、覆盖秸秆或者地膜等方法。

It is important that slightly saline water is rationally utilized to mitigate the shortage of water resource for agriculture development in North China plain.Based on the long-time experimental data in Quzhou station of China Agricultural University,dynamic type,leaching condition and requirement of soil salinity were analyzed,and strategy of saline water irrigation in North China Plain was discussed.The results showed that dynamic type of soil salinity was divided into sufficient and insufficient leaching types;the soil was in a state of leaching completely if the saturated conductivity was below 6 dS/m when the planting system was winter wheat and maize in North China Plain;leaching requirement of saline water in North China Plain was 368 mm for winter wheat and 327 mm for maize,which were calculated by stable salt balance equation.Planting salt-tolerant crop was suggested according to improving crop salt stress and osmotic stress capacity;increasing irrigation frequency,changing irrigation method,leaching with additional irrigation,leaching before sowing,treating the soil with organic or inorganic materials,covering straw or mulching film were suggested according to decreasing soil salinity content.