盐碱地水盐调控研究

高效安全利用咸水资源是提高环渤海低平原区农业生产可持续发展的重要保障。本文针对该区淡水缺乏、咸水充沛和土壤盐碱贫瘠等因素制约农业生产的问题,回顾了20世纪80年代以来在以中国科学院南皮生态农业试验站为典型代表站点的黄淮海缺水盐渍区开展的以盐碱地治理和农田生产力提升为目标的农田水盐运移过程及调控研究成果。20世纪50—60年代,该区域的工作主要是通过建立排水系统减少区域洪涝灾害发生。20世纪80年代,通过研究提出了控制盐碱的合理浅层地下水水位阈值,形成了以浅层地下水优化治理盐碱地提高农业生产的技术体系;20世纪90年代以来形成了微咸水资源安全灌溉理论及技术体系,冬小麦咸水灌溉阈值从3 g·L~(-1)提升到5 g·L~(-1),并阐述了微咸水灌溉阈值提升的理论基础;近10年来研究并阐明了农田生态系统水盐运移过程及主要限制因子调控机理,研发了以集蓄雨水、咸水利用、合理引水和节约淡水为核心的农田多水源综合利用技术,集成了农田多水源综合利用模式。根据多年的研究积累,以突破水土资源限制农业生产的问题为导向,实施了国家区域战略性增粮工程渤海粮仓科技示范工程,取得了明显的社会、经济和生态效益。在农田水盐研究方面,未来将以提高综合效益和资源利用效率为核心,开展基于生态平衡的作物产量、质量和资源利用效率的协同提升研究,适应区域水土资源的农业绿色发展研究,微咸水高效安全利用的机理过程、技术研发及示范工作,为该区农业可持续健康发展提供理论依据和技术支撑。

Regulations of salt and water of saline-alkali soil: A review

The safety utilization of saline water resources guarantees sustainable development of agricultural production in the Low Plain near the Bohai Sea. Focusing on water shortage and soil salinity, a series studies were conducted on reclamation of saline soils and regulation of water and salt transportation in the farmlands at Nanpi Eco-Agricultural Experimental Station of Chinese Academy of Sciences, where is a typical site of saline and water deficit regions in the North China Plain. This paper reviewed the study results of the development process for reclamation of saline soil and regulation of water and salt transfer in the farmland. Before the 1980s, most works in the region focused on reduction of flood risk through building of irrigation and drainage canals. In the 1980s, researches focused on optimal shallow groundwater regulation, saline soil utilization and water-saving technologies in the farmland with the aim of resolving actual agricultural production problems in saline soil areas. The researchers proposed threshold values for shallow groundwater table with no secondary salinization and developed irrigation scheme for winter wheat. In the 1990s, researches on the mechanisms and technologies of saline water irrigation were carried out to improve winter wheat grain yield and reduce fresh water utilization in the region. The threshold salinity for saline water irrigation was improved from 3 g·L^-1 to 5 g·L^-1. Meanwhile, researchers explained the reasons for the threshold value increase. In recent 10 years, the mechanisms and technological modes of multiple water resources utilization (precipitation collection, safe shallow saline water utilization, reasonable water transfer and water saving) in the farmland was analyzed. The modes included salt tolerant cultivars planting, soil salt transformation technologies, optimal irrigation schedule and organic manure reduction of salt accumulation. According to water quantity and quality, the optimal irrigation schedule was developed based on the available water resources. This included sufficient irrigation before winter, drought resistant irrigation in spring and emergency irrigation after maize sowing. On the basis of previous studies, an integrated technological mode for multiple water resources was developed. Meanwhile, the "Bohai Granary Demonstration Project of Science and Technology" was implemented, which had significant social, economic and ecological benefits. In future, research work will mainly focus on synergetic promotion of crop quality, quantity, resource use efficiency and green agriculture development based on available water and soil resources and the requirements of the local people. These works provided theoretical and technological basis for sustainable development of localized agriculture in the region.