Abstract:Based on systematic sampling and testing of topsoil in Gaomi city, total and effective amounts of N, P, K, Cu, Zn, Mo, B, pH and organic matter data have been obtained. The available geochemical characteristics and its controlled factors are studied by means of data statistics, correlation analysis and comparative analysis. It is showed that the total amount of soil nutrient elements, pH, organic matter and soil type all have certain effects on the available state of elements. The total amount of elements is positively correlated with their available amount, and positively correlated with the availability of P, K, Cu and Zn. The total amount of some elements have synergistic effects on the available amount and availability of different elements, such as the total amount of N is positively correlated with the available amount of P, the total amount of P is positively correlated with the available amount of K, Cu and Zn, the total amount of Zn is positively correlated with the available amount of P, Cu, and the total amount of P is negatively correlated with the available amount of N and P, and negatively correlated with the available amount of N and P. The availability of Cu, Zn and Mo is negatively correlated, and positively correlated with B availability and availability; organic matter is positively correlated with nutrient availability, and positively correlated with K, Zn and B availability, and negatively correlated with N availability. For example, in brown soil with the lowest pH and organic matter, N, P, K, Mo and Cu are the highest; in Shajiang black soil with the highest pH and relatively high organic matter, B is the highest.