摘要
模拟不同覆膜开孔率下的蒸发试验,研究了蒸发过程中不同覆膜开孔率下土体湿润锋及水盐运移情况的动态分布特征。结果表明:随蒸发历时的延长垂直湿润距离增大,在蒸发1 d后垂直湿润距离的增加量最大,蒸发结束时随覆膜开孔率的增大垂直湿润距离减小;随蒸发历时的延长土体剖面内的含水量在减小,表层减小最快,剖面底部边侧含水量有所增加;盐分则呈现向表层和底部范围增加,剖面中部的含盐量相对减小的动态变化;蒸发结束时土体剖面上同一位置处含水量随开孔率的增大在减小,盐分则表现随开孔率增加表层返盐明显,土体剖面中下部的盐分向远离滴头的斜下方运移,在湿润锋处聚集。而各覆膜开孔率下累积蒸发量与蒸发时间的开平方呈线性关系,累积蒸发量的增量与开孔率呈幂函数关系。
Plastic film mulching has been widely used in crop planting in arid areas,but due to the seeding holes and other factors,entire mulching can not be performed in the field,and this must affect the distribution of soil water and salt content.Evaporation was simulated with different holes opening ratio to study the dynamic distribution characteristics of wetness van and soil water and salt transfer with different holes opening ratio in evaporation process.The results indicated that vertical wetness distances were increasing with the elongation of evaporation time,and the increment was the biggest after a day of evaporation;The vertical wetness distances were depressed with holes opening ratio increasing at the end of evaporation.The soil water content was inducing with the extension of evaporation time,it was the most rapid in the top layer,but it increased in the bottom of soil profile;The soil salt content was increasing in top and bottom layers.At the end of evaporation the soil water content was reducing with hole opening ratio increasing at the same profile position,but the increased salt content accumulated at top layer was getting higher with hole opening ratio increasing,and the soil salt content of lower profile was moving along inclined below direction,and assembled in the wetness van.There was fine linear relationship between cumulative evaporation and evaporation time,and there was also powerful function relationship between cumulative evaporation increment and open holes ratio.
出处
《干旱地区农业研究》
CSCD
北大核心
2011年第1期14-21,共8页
Agricultural Research in the Arid Areas
基金
国家科技支撑计划课题"干旱区膜下滴灌农田盐分调控与微咸水利用技术研究"(2007BAD38B01)
新疆自治区重大科技专项课题(20073117-1)
国家863项目"水盐调控精量灌溉技术"(2006AA100207)
陕西省重点学科建设专项资金资助项目
关键词
覆膜开孔率
湿润锋
累积蒸发量
返盐量
hole opening ratio
wetness van
cumulative evaporation
increased salt content accumulated
