基于水盐生产函数的绿洲灌区水盐调控研究

土壤次生盐碱化是新疆灌溉农业所面临的最大环境问题。灌溉农业的快速扩展与灌排系统不完善是造成土壤次生盐碱化发生与恶化的关键因素。以水盐生产函数为依据,计算了不同生育阶段及全生育期阶段棉花相对产量与土壤全盐的关系,依据该计算结果对塔里木灌区的土壤盐化程度做了初步划分。基于塔里木灌区地下水埋深较浅且多为微咸水的事实,比较深入地探讨了地下水合理的动态水位及作物对潜水利用问题。最后,提出了灌区水盐调控的对策,强调排水系统的通畅运行是控制土壤次生盐碱化的关键,通过排水系统和减少灌溉定额使作物生长期的地下水埋深控制在1.6~2.1 m内,不但可以减少排水成本,而且也可使作物充分利用地下水,同时促进塔里木河水质的改善。

Control of Soil Water-salinity Variations based on Crop-salt-water Production Function in Tarim Irrigation Area

Soil secondary salinization is the biggest environmental problems for irrigated agriculture in Xinjiang.The results based on the brief analysis of the background of soil secondary and the different development stages showed that rapid expansion of irrigated agriculture and defective of irrigationdrainage systems were the key factors for soil secondary salinization,a direct threat to the sustainable development of the cotton industry.According to salt-water production function theory,the different stages and the whole growing stage of cotton relative yield were calculated and a preliminary classification of the soil salinization for Tarim irrigation area was done on the basis of the calculated results.Due to the presence of shallow groundwater table with poor quality in Tarim Irrigation area,the reasonable groundwater levels and groundwater contribution to crop water use were profoundly discussed.The countermeasures for soil secondary salinization control mainly refer to establishing irrigation-drainage systems,reducing irrigation norm and so on.