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高水位地区作物生长关键期采用微咸水或咸水灌溉被证明在一定条件下可以起到增产正效应,但同时却存在着土体盐分积累及其对下茬或次年种植影响的生态负效应.为探讨消除或抑制微咸水或咸水灌溉对土壤盐分积累的生态负效应,保证作物种植增产的正效应,本文在河北近滨海高水位盐碱区开展了为期2年的试验研究,探讨了旱季微咸水或咸水灌溉带来的盐分异位积累与离子分布变化特征,分析了雨季关键期暗管适时排盐对土壤盐分的立体调控生态效应.结果表明:旱季咸水灌溉后土壤经历“积盐-脱盐-二次积盐”3个阶段;灌溉初期,1 g·L~(-1)咸水灌溉处理下0~50 cm土体脱盐,土壤含盐量随土壤深度增加而增加,HCO_3~-含量增加,其他离子含量降低;6与13 g·L~(-1)咸水灌溉处理下0~50 cm土体积盐,土壤含盐量随土壤深度增加而降低,HCO_3~-含量降低,其他离子含量增加;雨季暗管适时立体调控脱盐效果显著,土壤脱盐率达16.0%~45.7%,同降雨量下,降水分布越集中,脱盐效果越好;周年时间尺度上,咸水灌溉小区土壤积盐量小于对照区;咸水灌溉处理小区冬小麦产量显著高于对照处理,1 g·L~(-1)处理高于6与13 g·L~(-1)处理.
The use of brackish or brackish water for key periods of crop growth in high water areas has been shown to increase yield and positive effects under certain conditions, but at the same time there is an ecological negative effect of soil salt accumulation and its impact on the next cropping or next year planting Effect.In order to explore the negative effect of reducing or inhibiting the ecological effect of brackish water or salt water irrigation on soil salinity accumulation and to ensure the positive effect of crop yield increase, this paper carried out a two-year experimental study in the coastal saline water- The salt accumulation and ion distribution changes caused by brackish or brackish water irrigation in the dry season were discussed, and the ecological effect of timely salinization on soil salinity during the critical rainy season was analyzed. The results showed that: Soil was subjected to 3 stages of “salt accumulation - desalination - secondary salt accumulation”. In the early irrigation period, salinity of 1 g · L -1 water was used to desalinate 0-50 cm soil, The content of HCO 3 ~ - increased while the content of other ions decreased. Under 6 and 13 g · L ~ (-1) saltwater irrigation treatments, the salt content of 0 ~ 50 cm soil volume decreased with the increase of soil depth , HCO 3 ~ - content decreased, other ions increased; rain tube At the same time, the desalination effect of the three-dimensional regulation was significant, the desalination rate of the soil was 16.0% ~ 45.7%, and the more the precipitation distribution, the better the desalination effect under the same rainfall. On the annual time scale, The yield of winter wheat in water irrigated area was significantly higher than that of control, and the treatment of 1 g · L -1 was higher than that of 6 and 13 g · L -1.