Abstract
Soil types of a Japanese apricot farm in Wakayama prefecture are generally classified into brown earth, yellow soil, gray lowland soil and lithosol. This experiment investigated the characteristics of nutritient eluviation in these soils to develop guidelines for good management according to the soil type. In any soil type, the higher the concentration of inorganic nitrogen in soil was, the higher the nitrogen concentration in percolated water became. The nitrogen concentration in percolated water increased in order from gray lowland soil, brown earth, yellow soil to lithosol. The amount of cation eluviation (ionic concentration in percolated water × percolated water volume) was higher in lithosol and gray lowland soil. Total cation equivalent correlated well with total anion equivalent regardless of soil type. This positive relationship suggested that cation was leached in the order of the amount of anion such as nitrate ion and sulfuric acid ion in percolated water. These findings suggested that considerable cation was leached due to the high concentration of nitrate ion in gray lowland soil or due to the amount of percolated water in lithosol.
