膜下滴灌盐碱地排水工程控盐效果试验研究

Experimental study on salt controlling effect in drainage system in saline-alkali land with drip irrigation under mulch

针对新疆玛纳斯河流域下野地灌区土壤盐渍化问题,以试验区已有的支排和农沟为基础,增加暗管排水工程,形成暗管和明沟相结合的排水系统,并对试验区膜下滴灌与明沟及暗管排水工程相结合的农田灌排模式控盐效果进行试验研究.设置距明沟(暗管)8,16,24 m处为取样点,于2012—2014年不同季节在试验区对地下水位、土壤剖面(0~200 cm)盐分进行监测,对土壤总盐含量进行分析,结果表明:暗管及明沟均能有效降低地下水位,明沟和暗管可将地下水位分别控制在1.6~2.2,1.5~2.2 m;2014年相比2012年,0~200 cm土层深度,暗管取样点处(8,16,24 m)土壤总盐含量分别下降42.99%,36.84%,24.41%;根系层(0~80 cm)土壤总盐含量分别下降50.34%,40.70%,30.76%;明沟取样点处(8,16,24 m)0~200 cm深度土壤总盐含量分别下降46.85%,38.12%,30.80%;根系层(0~80 cm)土壤总盐含量分别下降54.88%,43.39%,33.21%.研究可为干旱、半干旱灌区有效治理盐碱地提供理论依据和技术参考.

In order to control the soil salinization,a series of tests were carried out on a piece of saline-alkali land in Xiayedi irrigation district of Manasi in Xinjiang,where the subsurface drainage was arranged based on the existing rows and farm ditch.The salt controlling effect in the drainage system combined with the subsurface drainage and the ditch drainage in the saline-alkali land with drip irrigation under mulch was studied experimentally.The sampling points were set at 8 m,16 m,and 24 m of the ditch drainage and the subsurface drainage respectively.The underground water table and soil salinity at depths of 0-200 cm were observed,during the different seasons of 2012-2014.The results show that both the subsurface drainage and the ditch drainage can control the underground water table,ranging from 1.6m to 2.2 m in the ditch draining area and ranging from 1.5m to 2.2m in the subsurface drainage area.Compared with the year 2012,soil total salt of each sampling point at depths of 0-200 cm in the subsurface drainage area decreases by 42.99%,36.84%and 24.41%in 2014.At the root layer,soil total salt of each sampling point decreases by 50.34%,40.70%and 30.76%.For the ditch drainage,soil total salt of each sampling point at depths of 0-200 cm decreases by 46.85%,38.12%and 30.80%.At the root layer,soil total salt of each sampling point decreases by 54.88%,43.39%and 33.21%.This study provides a reference for saline-alkali land management in arid and semi-arid areas.