膜下长期滴灌土壤盐分的空间分布特征与累积效应

通过对不同土壤质地和不同滴灌年限两个方面对新疆棉田膜下滴灌盐分的运移与积累规律的研究,结果表明:对于不同土壤质地,壤土中的盐分分布大致呈抛物线型,在40～60 cm处盐分积累量达到最大值.粘土中盐分分布大致呈"S"型,在60～80 cm处土壤盐分积累达到最大值;不同滴灌年限中随着滴灌年限越长,棉田中地表盐分积累越少,而在40～60 cm的盐分积累则越多.分析认为棉田土壤仅通过膜下滴灌淋洗盐分是不够的,必须与一定的灌排水技术相配合才能很好地防止棉田次生盐渍化.

Spatial distribution and accumulation pattern of soil salinity with long term drip irrigation under plastic mulching

Soil salinity distribution and accumulation pattern of different soil texture and plantation age with long term drip irrigation under plastic mulching in Xinjiang were studied by using a polynomial approximate simulation. The total salinity showed parabola distribution and reached the highest value at 40 ～ 60 cm in loam soil, while it showed logistic distribution and reached the highest value at 60 ～ 80 cm in clay. The total salinity decreased with increasing plantation age in surface soil, but increased with increasing plantation age at the deeper layer and reached its highest value at the depth of 40 ～ 60 cm. This indicated that drainage irrigation technology should be combined with drip irrigation under plastic film mulching to avoid soil degradation by salinization.