云南滇池流域强烈灌溉条件下西芹大棚土壤水分动态特征

利用TRIME-T3型TDR仪土壤含水量测量系统和WM-1型负压计系统现场监测了强烈灌溉条件下整个作物生长期西芹大棚土壤水分、土壤负压(基质势)的动态变化;研究表明,不同深度土壤含水量受强烈灌溉的影响程度不同,0.3 m深度处受影响最大,1.0,2.0 m深度处受影响最小;受灌溉的影响,0.3,0.6,1.0 m深度处负压有所波动,其中0.3 m深度处负压的波动幅度最大;2.0 m深度处的土壤一直处于"饱和-非饱和"两种状态的转换之中;在地下水埋深为2.0 m左右,且上部土层的渗透性较差(饱和渗透系数仅为0.04 m/d)的情况下,地下水水位受灌溉的影响极小.

MOISTURE CONTENT AND MATRIC POTENTIAL OF SOILS UNDER INTENSE IRRIGATION IN CELERY GREENHOUSE,DIANCHI CATCHMENT,YUNNAN PROVINCE

Moisture content and matric potential of soils under intense irrigation in celery greenhouse in Dianchi catchment were monitored by using TDR (TRIME-T3) and WM-1 tensiometer during the growth period of celery. It indicated that intense irrigation drastically affected the moisture content of soil at depth of 0.3 m below land surface, and had little effect on the moisture contents of soils at depths between 1.0 and 2.0 m below land surface. The matric potentials of soils fluctuated at depths of 0.3, 0.6 and 1.0 m below land surface, with the largest extent at depth of 0.3 m, under intense irrigation.While the soils at depth of 2.0 m below land surface were unsaturated or saturated during the period of celery growth. The intense irrigation has less effect on groundwater table when water table is about 2.0 m and conductivity coefficient of uppermost soils is low (saturated conductivity coefficient is about 0.04 m/d).