Spatial variability of Soil Nutrients and Influencing Factors in a Vegetable Production Area of Hebei Province in China

This study was conducted to determine soil nutrient spatial variability and the factors influencing it in a vegetable production area using traditional statistics and geo-statistics. The study area encompassed 55 ha and consisted of 182 farmer's plots belonging to six production groups in the Yutian county of China. Two hundred and seventeen soil samples were collected on a 50x50-m grid at depths of 0-20 cm prior to the plots being sown for cabbage. Vegetable production history, including varieties, rotation systems and fertilizer use, at the sampling sites was also examined. Soil pH, organic manure (OM), NO ₃ - -N, available P, K, Zn, and other nutrients and particle size were measured. The results showed that N, P, K and Zn were the main limiting nutrient factors in the soil. Distinct semi-variance structures of spatial variability were observed for soil NO ₃ - -N, available P, K and Zn, with the range of spatial correlation being 204-348 m. Significant spatial distribution similarity was found for soil NO ₃ - -N, P, K and Zn, with relatively high contents of all these nutrients in some areas of the study area and relatively low contents in other areas. The correlation of soil NO ₃ - -N, P and K content with vegetable production history and fertilizer application rates (N, P₂O₅ and K₂O) suggested that vegetable variety and history of fertilizer use are important factors to be considered in the development of a soil nutrient management program in the study area.