摘要
为研究膜下滴灌暗管排水条件下棉田土壤盐分变化规律,该研究基于新疆122团盐碱地暗管排水试验,通过膜下滴灌淋洗,监测0~200 cm土层土壤盐分变化,并应用HYDRUS-2D数值模型,模拟分析了暗管排水条件下,盐渍化棉田在2013和2014年生育周期内和秋季返盐阶段土壤盐分变化情况。结果表明:模拟值与实测值之间吻合度较高,模型可用于预测盐碱地土壤层剖面盐分含量变化。模拟结果显示,棉花生育期内滴灌条件下,盐分持续下降;棉花收获后土壤表层开始返盐;2013和2014年棉花吐絮期土壤含盐量与初始含盐量相比,在膜下,0~80 cm土层平均脱盐率分别达到了41.11%和55.56%;膜下及膜间,0~80 cm土层平均脱盐率分别达到了14.05%和17.88%;棉花收获后,土壤表层返盐明显,但与初始含盐量相比仍较低,0~80 cm土体盐分分别平均下降了5.55%和10.15%,0~200 cm土体盐分分别平均下降了2.58%和4.96%,说明暗管控制条件下,使用滴灌淋洗和暗管排盐的模式,土体内的盐分总量呈现降低趋势。研究可为西北内陆干旱区暗管排盐技术和膜下滴灌的推广和应用提供理论支撑和科学指导。
With the long-term use of under mulched drip irrigation,the problem of salt accumulation in farmland soil has attracted increasing attention.In order to explore the changes of soil salt content in a cotton field under mulched drip irrigation with subsurface pipes drainage,a subsurface pipes drainage experiment was conducted in the saline-alkali soil of Xinjiang 122 group in 2013 and 2014.The buried depth of the subsurface pipes is 2.2 m,and the spacing is 48 m.The changes of soil salt content in the 0-200 cm soil layer were monitored through under mulched drip irrigation.Sampling points were set at 8,16,and 24 m perpendicular to the subsurface pipes and the sampling time was set to the cotton seedling,flowering,and boll opening periods of 2013 and 2014,respectively.Soil electrical conductivity(EC)was detected by an electrolytic conductivity meter at a soil-to-water ratio of 1:5.Based on the HYDRUS-2D model,a mathematical model of soil salt content changes in cotton fields under mulched drip irrigation with subsurface pipes drainage was established,and the HYDRUS-2D simulation results and experimental data were compared.The range of the statistical analysis index salt content RMSE and NSE are 0.39-1.26 g/kg and 0.66-0.97,respectively.They were within the acceptable range,which verified the reliability of the numerical simulation method.On this basis,the model simulated and analyzed the changes of salt content with time in 0-80 cm soil layer,the desalination rate of root layer,and the desalination rate of 0-200 cm soil layer in the salt content of 2013 and 2014 during cotton growth and the autumn salt return stage.The simulation results showed that under mulched drip irrigation during the growth period of cotton,the soil salt content continued to decrease,and the soil surface began to return after the harvest.The soil salt content in the cotton boll opening period in 2013 and 2014 was compared with the initial salt content,the average desalination rate of the 0-80cm soil layer reached 41.11%and 55.56%,respectively.And the total salt content of the 0-80cm soil layer under and between the mulching films decreased by 14.05%and 17.88%,respectively.After the cotton was harvested,salt returned to the upper layer of soil.However,it still showed a decrease compared with the initial salt content.The average salt content of 0-80 cm soil decreased by 5.55%and 10.15%,and the average salt content of 0-200 cm decreased by 2.58%and 4.96%.These results showed that the total salt content in soil showed a decreasing trend by using under mulched drip irrigation with subsurface pipes drainage mode.The average soil desalination rate of 0-8 m(2.97%and 5.71%)from the subsurface pipes was significantly higher than that of 8-16 m(2.44%and 4.64%)and 16-24 m(2.32%and 4.52%),but the difference between the latter two was small.The area close to the subsurface pipes had a low soil salt content,while the area far away from the subsurface pipes had a higher soil salt content.According to the law of solute transport and the principle of salt balance,the salt in the soil would change from the area with more salt to less salt over time.As a result,the overall soil salt content decreased,and the root layer salinity decreased more obviously.The results revealed the changing law of soil salt content in the cotton fields under mulched drip irrigation with subsurface pipes drainage,aiming to provide theoretical support and scientific guidance for the popularization and application of subsurface pipes drainage technology and under mulched drip irrigation in the inland arid area of Northwest China.
作者
刘洪光
白振涛
李开明
Liu Hongguang;Bai Zhentao;Li Kaiming(College of Water&Architectural Engineering,Shihezi University,Shihezi 832000,China;Key Laboratory of Modern Water-Saving Irrigation of Xinjiang Production&Construction Group,Shihezi University,Shihezi 832000,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2021年第2期130-141,共12页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家“十三五”重点研发计划(2016YFC0501406)
国家自然科学基金项目(51669029)
南疆重点产业创新发展支撑计划项目(2020DB001)
石河子大学科技特派员项目(KJTP202017)
八师石河子市科技合作计划项目(2019ZH13)。
关键词
土壤
盐分
棉花
膜下滴灌
暗管排水
数值模拟
HYDRUS-2D
soils
salts
cotton
under mulched drip irrigation
subsurface pipes drainage
numerical simulation
HYDRUS-2D
