Characteristics and Influencing Factors of Soil Fertility in Saline Alkali Farmland in Hetao Irrigation Area
This study aims to explore the environmental factors affecting soil fertility in saline alkali farmland in the Hetao Irrigation Area,and provide essential data and a foundation for decision-making regarding soil improvement,fertility enhancement,and ecological governance.A combination of outdoor sampling and indoor laboratory analysis was used to study the soil fertility characteristics and environmental impact factors of different saline alkali cultivated lands in the Hetao Irrigation District.The results show that:① The average salt content of saline alkali farmland in the Hetao Irrigation District is 4.5 g·kg-1,which indicates a moderate level of salinization.The overall soil fertility,except for total nitrogen which is at a deficient level,is above the appropriate level for other nutrients.② Significant differences in soil fertility were observed among farmlands with different levels of salinization.As soil salinization intensifies,the organic carbon and total nitrogen contents decrease significantly(P<0.05).③ The type of crops grown in a given year also affects the soil fertility characteristics and physicochemical properties.Farmlands planted with gourds showed higher organic carbon,available phosphorus,and available potassium levels compared to other crop types.In contrast,the farmlands planted with corn had the lowest levels of organic carbon,available phosphorus,and available potassium,with the exception of total nitrogen content.④ The soil texture of cultivated land in the Hetao Irrigation District varies due to differences in soil particle size distribution,and significant differences(P<0.05)were found in the organic matter,total nitrogen,and available potassium contents across different soil textures.Clearly,soil fertility characteristics in cultivated land in the Hetao Irrigation Area vary under different levels of salinization,crop types,and soil textures.Therefore,in the plan for improving soil fertility and ecological governance of cultivated land in the Hetao Irrigation Area,targeted measures should be adopted based on factors such as salinization levels,crop types,and soil texture,to better improve vegetation ecology and enhance soil fertility.