咸水安全利用农田调控技术措施研究进展

淡水资源短缺已经成为全球性的问题,开发利用地下咸水资源,发展农业灌溉已成为各国关注的焦点问题。微咸水或咸水代替部分淡水进行农业灌溉,在一定程度上可缓解淡水资源的不足,但咸水和微咸水灌溉带来的土壤积盐和作物减产等问题始终是研究的重点和难点。本文从咸水或微咸水灌溉带来的潜在土壤盐渍化危害入手,就如何应对咸水和微咸水灌溉带来的次生盐渍化问题,通过总结前人大量的研究成果,分析了减轻土壤盐渍化对作物危害的各种途径,从微咸水灌溉和咸水灌溉两个层面就优化农田管理农艺措施、生物措施、水利工程措施等方面进行概述。重点介绍了咸水或微咸水灌溉对土壤微环境的影响,优化田间管理农业措施(如合理的灌溉制度和灌溉方式、覆盖、深耕等),土壤中施入有机物质(如植物秸秆、有机肥、绿肥、生物质炭等)和无机土壤改良剂(如石膏、沸石等)、施用根际促生菌肥、种植盐土植物和耐盐作物品种等,以及咸水结冰灌溉、暗管排盐等水利工程措施,这些都是降低咸水灌溉带来的土壤盐害行之有效的方法。以微咸水或咸水补灌为核心,结合雨水资源利用,通过种植耐盐植物品种、增施土壤微生物肥、土壤调理剂等措施提高土壤缓冲能力,配套垄作和地膜覆盖等降低土壤蒸发措施,抑制土壤盐分表层积聚,配套秸秆还田和土壤耕作技术,提高土壤蓄雨淋盐和养分快速提升,集成微咸水安全高效灌溉技术模式,制定规范化的技术应用规程,有机地结合各种改良措施,可有效控制咸水和微咸水灌区土壤次生盐渍化,达到咸水资源的高效安全可持续利用,提升水资源保障能力。

Advances in agricultural practices for attenuating salt stress under saline water irrigation

The shortage of freshwater resources has been a growing global concern. The use of saline groundwater and brackish water is an important way of solving water shortage in irrigated farmlands around the globe. Saline water and brackish water could partly replace freshwater in irrigated agriculture, but saline water or brackish water irrigation results in the accumulation of salts in surface soil and in the reduction of crop yield. This has been a significant research issue associated with water shortage and agricultural production in recent decades. In this study, measures developed to mitigate secondary salinization due to saline water irrigation were summarized. The measures included improving cultivation practices, biological practices and engineering designs that ameliorated soil salt stress under brackish water or saline water irrigation. The paper highlighted relevant current literatures and introduced detailed optimization agricultural cultivation manages, including the development of reasonable irrigation methods, mulching and subsoiling. There were also soil amendments with organic matter including crop residues, farm manure, green manure, gypsum, zeolite, etc. There was inoculation with plant growth promoting rhizobacteria, planting halophytes or salt-tolerance crop species, etc. All these measures were efficient in mitigating soil salt stress under saline water irrigation. In saline water and brackish water irrigation, the combination of rainfall with irrigation improved soil buffer capacity to salinity. Also planting salt tolerant crop cultivars and using biological fertilizers and soil conditioners could decrease soil salinity. Ridging and plastic mulching reduced evaporation loss while concurrently decreasing salt concentration in surface soil. Straw return to soil and deep tillage improved soil nutrient condition, water holding capacity and salt leaching. The integration of safe and efficient mode of saline water and brackish water irrigation, the designing of standard technology and application procedure, and the combination of various organic substances were all ameliorative measures. Field soil salt stress under saline water and brackish water irrigation was efficiently controllable. The effective, safe and sustainable use of brackish and saline water was achievable in improving water availability for agricultural production.