The soil physical and chemical characteristics were examined in the lower reaches of Tarim River

southern Xinjiang.The results showed that the indices of soil properties including organic matter

total nitrogen

total kalium and so on except total phosphor existed vertical difference among different soil layers and the layer producing significant difference was at 50 cm depth of soil.About the water content of soil in the 0~15 cm depth

there were not obvious difference among different places which had various distances away from river course of Tarim River.From 15cm depth the water content of each soil layer locating at 50 m site was greatly different from the water content of each layer locating at 300m or 500m site

but the water content of each soil layer of 300m site was similar to 500m site's.In a 0~50cm depth

the content of total N(y) has obvious linear relation with the content of organic matter(x)(y=0.0278 0.05x

R2=0.9524).In a 50~170 cm depth

it shows exponential relation(y=0.0659e0.3126x

R2=0.904).According to soil quality

the lower reaches of Tarim River is generally divided into upper parts and lower parts and the content of nutrition in upper parts soil is high relatively.In the past fifty years

the degree of soil desertification in the lower reaches of the Tarim River turned more worse

for example

the soil organic matter decreased hardly and the soil pH value increased obviously.