Abstract: In order to understand the distribution of soil nutrients in Dali winter jujube greenhouses in different soil layers and the changes with the planting years, the uncultivated wasteland was used as a control, and the Dali winter jujube greenhouses planted for 3,7, and 10 years were selected as soil samples. The distribution of nutrients in different planting years and soil layers, and the correlation between different nutrient indexes in winter jujube greenhouses were investigated. The results showed that the content of organic matter and total nitrogen was relatively low in different planting years, while available potassium, available phosphorus, total calcium, and total magnesium levels were relatively high. Therefore, it was recommended that farmers increased the application of organic and microbial fertilizers to improve soil quality and enhance plant growth conditions. The contents of organic matter and total nitrogen in the surface soil (0-20 cm) were higher, while the contents of total water-soluble salt, available potassium and available phosphorus decreased with the increase of soil depth. The contents of total calcium and total magnesium were the highest in the 20-40 cm soil layer. Correlation analysis showed that planting years had little effect on soil nutrient content. Under the influence of fertilization methods, soil depth was extremely significantly negatively correlated with organic matter, total nitrogen and available potassium, and significantly negatively correlated with available phosphorus. There was also a certain correlation between soil nutrients.

Key words: soil nutrient, Dali winter jujube, planting years, greenhouses, Shaanxi Province