苏北滩涂区水盐调控措施对土壤盐渍化的影响研究

苏北沿海滩涂区具有大面积存在盐渍化风险的可利用耕地。近年来不合理的开发利用使该地区土壤盐渍化程度加重。通过微区定位试验,对该区典型滩涂盐渍化土壤进行微咸水灌溉结合农艺处理的试验研究,探讨了利用水盐调控措施防控该地区土壤盐渍化程度的可能性。结果表明,在低矿化度(3 g/L左右)的微咸水灌溉条件下,石膏处理和秸秆覆盖处理均可以有效降低各层土壤SAR值,降低耕层土壤盐分含量,并且促进作物生长;当灌溉水矿化度达到6 g/L时,石膏处理仍具有一定控盐效果,但覆盖处理已不能控制土壤表层盐分含量的升高,作物的生长开始受到影响;当灌溉水矿化度达到10 g/L时,各处理耕层均显著积盐,作物生长受到显著影响。因此,6 g/L及以上矿化度的咸水不能用于该地区的灌溉,6 g/L以下浓度的咸水灌溉须配合石膏和秸秆覆盖处理使用。该研究为苏北滩涂区农田管理提供一定的参考依据。

Effects of adjustment measure of water-salinity on soil salinization in the coastal area of North Jiangsu Province

Available cultivated land which existing soil salinization risk is largely distributed in the coastal area of north Jiangsu Province,field plot experiments were conducted there for purpose of studying the effect of adjustment measure of water-salinity on improving soil salinization.The results showed that both gypsuming and straw mulching treatments could decrease SAR in each soil layer thus could lower the trend of the soil alkalinization and reduce the soil salt content when irrigated with brackish water of 3 g/L.Gypsuming treatment could to some extent improve soil salinization condition while straw mulching treatment could not control the increase of soil content under the condition of brackish water of 6 g/L irrigation.When irrigated with 10 g/L brackish water,neither could control the exacerbation of soil salinization condition.Low concentration brackish water could be used for irrigation cooperated by agronomic practices.When the concentration of brackish water ≥6 g/L,it could not be utilized for the field.The research results can instruct the field irrigation in the coastal region of north Jiangsu Province.