Analysis on the Characteristics of Soil Available Nutrients in Orchards of Longyan City

By finding out the effective nutrient status of soil in the orchards of Longyan City, and exploring the effects of soil pH and organic matter on the effective nutrients, it would provide a theoretical basis for the scientific guidance of fruit farmers’ fertilization, increasing the fruit yield and improving the fruit quality. A total of 66 soil samples were collected from the representative orchards in Longyan City. The contents of alkaline hydrolysis nitrogen, available phosphorus, available potassium, available calcium, available magnesium, available zinc, and effective boron were measured. According to the grading standard of soil nutrients, the abundance and deficiency of soil nutrients were analyzed and evaluated, and the correlation and regression analysis among the available nutrients, pH and organic matter were carried out. The results showed that: The soil alkaline hydrolysis nitrogen in the orchards of Longyan City was at the very rich level, with an average of 159 mg·kg⁻¹. The available phosphorus was at the rich level, with an average of 26.3 mg·kg⁻¹. The available potassium was at the medium level, with an average of 148 mg·kg⁻¹. The percentage of samples with the alkaline hydrolysis nitrogen, available phosphorus and available potassium in the range of medium to extremely rich levels reached 93.94% , 98.48% and 57.58% , respectively. The available calcium was at the deficient level, with an average of 536.3 mg·kg⁻¹. The percentage of samples with the available calcium in the range of deficient to extremely deficient levels reached 77.27%. The available zinc was at the rich level, with an average of 2.5 mg·kg⁻¹, and all the samples were in the range of medium to extremely rich levels. The available magnesium and available boron were at the extremely deficient level, with an average of 29.9 mg·kg⁻¹ and 0.16 mg·kg⁻¹, respectively. The available magnesium and available boron of all the samples were within the range of deficient to extremely deficient levels. There were significant positive correlations among the available calcium, available magnesium, available zinc and pH. There was a significant positive correlation between the alkaline hydrolysis nitrogen and organic matter, and there was a significant positive correlation between available phosphorus and rapidly available potassium and organic matter. In general, the soil alkaline hydrolysis nitrogen, available phosphorus and available zinc in orchards of Longyan City were relatively abundant, while the available calcium, available magnesium and available boron were relatively scarce. There were curvilinear relationships among the alkaline hydrolysis nitrogen, available phosphorus, rapidly available potassium and organic matter, as well as the available calcium, available magnesium, available zinc and pH, of which the curve fitting were good.