Abstract: Taking saline-alkali land in Yinbei area as the research object, the effects of four land use patterns （dry land, paddy field, shrubbery and grassland） on soil bulk density, total porosity, organic carbon content, total nitrogen content, total phosphorus content, total potassium content, pH and total salt content in 0~20 cm and 20~40 cm soil layers were studied. The results showed that the soil physical and chemical properties of different land use types in Yinbei area were significantly different （P<0.05）. The soil bulk density of dry land and paddy fields was higher than that of shrubland and grassland, and the total soil porosity was lower than that of shrubland and grassland. The soil organic carbon and total nutrients of four land use types were similar in 0~20 cm and 20~40 cm soil layers. The content of organic carbon and total nitrogen was the highest in shrubbery, followed by dry land and paddy fields, and the lowest in grassland. The soil total phosphorus content in dry land and paddy fields was significantly higher than that in shrubbery and grassland（P<0.05）. The total potassium content was the highest in dryland soil and the lowest in paddy fields. The soil pH and total salt content of grassland were significantly higher than those of the other three land use types（P<0.05）, except for the 20~40 cm soil layer of dry land. The weighted gray correlation analysis showed that the correlation degree of soil physical and chemical properties in 0~20 cm and 20~40 cm soil layers was the highest in shrubbery, followed by dry land and paddy fields, and the lowest in grassland, indicating that shrubbery had the best effect on improving soil physical and chemical properties in Yinbei saline-alkali land.

Key words: saline-alkali land, improvement, land use pattern, soil physical and chemical properties, gray correlation analysis, Yinbei region