摘要
冬季咸水结冰灌溉技术是滨海区高矿化度咸水利用和盐碱地改良的有效手段,该项技术依据咸水结冰融化过程中咸淡水分离的基本原理,基于区域气候特点、土壤水盐运移规律以及作物生长发育规律,在冬季抽提当地高矿化度地下咸水对盐碱地进行灌溉,并在冬季低温作用下迅速冻结成咸水冰,春季咸水冰层融化过程中,咸淡水分离入渗,其中先融化的高矿度咸水先入渗,而后融化出的低矿化度微咸水和淡水的入渗对土壤盐分具有较好的淋洗作用,以上过程实现了春季土壤返盐期的土壤脱盐,结合春季地表覆盖抑盐措施和夏季降雨淋盐,土壤的低盐条件得到保持,保证了作物和植物整个生长期的正常生长。该项技术改变了滨海盐碱区土壤水盐运移特征,使春季土壤积盐期变为脱盐期,咸水结冰灌溉后,春季耕层土壤盐分由最初的12g×kg^(-1)迅速降低至4 g×kg^(-1)以下,脱盐率达到66%以上,实现了棉花、油葵、甜菜等作物在滨海重盐碱地中的种植,提高了柽柳、枸杞、白蜡等盐生植物和耐盐植物的扦插移栽成活率,咸水结冰灌溉当年便获得了籽棉产量3 t×hm^(-2)、油葵1.5 t×hm^(-2)、甜菜60 t×hm^(-2),以及90%以上的盐生植物和耐盐植物的扦插成活率,促进了滨海盐碱区盐碱地的开发、农业发展和生态环境建设。近年来,通过系统的研究,我们探明了咸水结冰灌溉过程中咸水冻融咸淡水分离规律,明确了咸水结冰灌溉对土壤盐分的淋洗效果,构建了冬季咸水结冰灌溉改良盐碱地技术体系,确立了冬季咸水结冰灌溉的灌溉时间、灌溉水量和水质等指标体系。本文在以上研究基础上,对盐碱地咸水利用的研究进展进行了总结,并对咸水结冰灌溉基本原理、影响因素以及土壤盐分淋洗效果等方面进行了概述,系统分析了冬季咸水结冰灌溉在盐碱地区农业生产、植被恢复以及咸水利用等方面
The use of freezing saline water to irrigate saline lands has proven an effective method of using highly saline water and reclaiming saline lands in coastal regions. The method was based on the basic principle of desalination during melting of frozen saline water in combination with soil water and salt movement characteristics and crop growth pattern in coastal region. In winter, the saline groundwater was pumped and irrigated saline farmlands. The low air temperature forced the irrigated saline water on the top soil to freeze into saline ice. With increasing air temperature in spring, water of high salt concentration melted firstly and infiltrated into the soil, and the slightly saline melting water and freshwater infiltrated into the soil late andeffectively facilitated leaching of soil salt. From the above process, freezing saline water irrigation induced soil salt leaching in spring, the period of soil salt accumulation. This, in combination with mulching in spring to control soil salt concentration and rainfall leaching in summer, lowed soil salt content to levels conducive for normal crop growth throughout the growth stages of the crops and plants. The natural characteristics of soil water and salt movement were modified by freezing saline water irrigation, which changed soil salt accumulation into soil salt leaching in spring after irrigation. Thus the remaining soil salinity in the root zone effectively decreased from 12 g.kg-1 to 4 g.kg-1 and the rate of salt leaching exceeded 66%. This facilitated the cultivation of crops including cotton, oil-sunflower and sugar beet in saline coastal regions of the Bohai Sea, and increased the survival rates of Tamarix ramosissima, Lycium barbarum and Fraxinus chinensis transplanted seedlings in the region. After first year freezing saline water irrigation, the yields of seed cotton, oil-sunflower and sugar beet were 3 t.hm-2, 1.5 t.hm-2 and 60 t.hm 2, respectively. Cutting and transplanted seedling survival rates of halophytes and salt-tolerant plants exceeded 90%. F
出处
《中国生态农业学报》
CAS
CSCD
北大核心
2016年第8期1016-1024,共9页
Chinese Journal of Eco-Agriculture
基金
中国科学院科技服务网络计划(KFJ-EW-STS-057)
国家科技支撑计划项目(2013BAD05B02
2013BAD05B05)资助~~
关键词
盐碱地改良
咸水利用
咸水结冰灌溉
植被恢复
盐分淋洗
Saline soil reclamation
Saline water utilization
Freezing saline water irrigation
Vegetation restoration
Soil salt leaching
