Abstract:After comparative analysis of the distribution characteristics of soil water and salt in farmlands ( 3 cotton fields and 1 orchard) and their shelterbelts in drip irrigation prevailing Kalamiji Oasis in the lower reaches of Tarim River, Northwest China through comparative tests and field monitoring, effects of the current drip irrigation pattern on farmlands within forest networks and their shelterbelts and main factors affecting salt-water dynamics in the soil within the forest network were studied and analyzed with the following conclusions obtained. ⑴ In Kalamiji oasis, the groundwater table in the fields lowers at a rate of 0.5 m a-1 as a result of popularization of drip irrigation and varies seasonally; it is relatively shallow in non-irrigation season and relatively deep in irrigation season; and over 1 m deeper in the latter than in the former. (2) As the impact of drip irrigation on soil never goes deeper than 80 cm, the irrigation supplies little water, almost nil, to groundwater, while the roots of farmland shelterbelt have to go deep into the soil to absorb water, thus leading to significantly lower soil water content in the shelterbelt than in farmland (p<0.01). (3) The current irrigation rate, 5 250 m3 hm-2 a-1 in the cotton field and 7 000 m3 hm-2 a-1 in the orchard are adequate to keep the soil (0~60 cm) low in salinity and basically satisfying the requirements of farmland desalination; but, in shelterbelt land soil salinity is obviously higher or 2~3 times higher than in farmland (p<0.01); surface accumulation of soil salts is apparent; as a result, the conductivity is 79.3%, 77.1%, 80.6% and 88.4% higher in loamy forest land, sandy forest land, clayey forest land 1 and clayey forest land 2 than in farmlands, respectively. (4) Comparison in soil water and salt contents between shelterbelt lands shows that the difference in depth of the groundwater table is the main factor for difference in soil water and salt content and consequently, forest lands, high in water content, are high in salinity, and vice versa in the 0~150 cm soil layer.