Impact of farmland shelterbelt patterns on soil properties, nutrient storage, and ecosystem functions in desert oasis ecotones of Hetao irrigated areas, China

The farmland shelterbelt system is considered an effective form of land management to improve the eco-environment and soil quality in fragile agricultural areas. Clarifying the effects of farmland shelterbelt patterns on ecosystem functions can guide ecological restoration in fragile ecosystems. Four typical farmland shelterbelt patterns (i.e., two-line pattern, four-line pattern, five-line pattern, and eight-line pattern) in desert oasis ecotones of Hetao irrigated area, northern China, were selected in this study. In these treatments, measurements of soil properties at a depth of 0–100 cm; vegetation attributes; microclimate; and soil water, carbon, nitrogen, and phosphorus storage were performed during three growing seasons in 2019–2021. The results demonstrated that the four-line pattern had higher soil organic content (0.339 g·kg−1), total nitrogen content (0.517 g·kg−1), and total phosphorus content (0.577 g·kg−1) than the other treatments, as well as the highest soil water (237.44 mm), carbon (544.93 g·m−2), nitrogen (953.72 g·m−2), and phosphorus storage (859.04 g·m−2) at the 0–100-cm soil layer. Moreover, dynamic variations in soil water and salt contents showed opposite trends during the growing season, i.e., they showed a gradual decrease and increase, respectively. Furthermore, principal component analysis, correlation matrix analyses, and network association analyses indicated close relationships among environmental factors, nutrient storage, and related ecosystem functions under different farmland shelterbelt patterns. The results of this investigation provide a useful theoretical basis for agricultural management and ecological restoration in ecofragile regions.