Korean Journal of Soil Science and Fertilizer ISSN:0367-6315(Print) 2288-2162(Online) 한국토양비료학회 학회지

The soil suitability grades are classifying as soil series by judging the potential productivity of the soil based on the yield of crops. The soil suitability grade is divided into four grades, which are very suitable, suitable, possible, and not suitable areas. The reason for classifying the grades is to help farmers in selecting crops to grow in consideration of the characteristics of the soil. Among the soil characteristics used previously to set the soil suitability grade of 66 crops, the five most common characteristics selected. As for the crop it applied as the determinant, the bracken with the largest number of plots selected among the crops excluding the crops with the crop exclusion criteria registered with the agricultural business. The relationship between yield and soil characteristics confirmed by examining the cultivated yield of local bracken and the soil characteristics of the plots. For subsoil, the highest yield was shown when the sub-soil texture were loam and silty loam with a clay content of 15 - 35%, the drainage grade was slightly poor, the available soil depth was >100 cm, the gravel content was 15 - 35%, and the slope was >30%. Based on this, the partial correlation coefficient was calculated. As a result, the drainage grade was the highest at 0.22, indicating the greatest influence. The corresponding soil suitability grade was applied to the soil characteristics of 1,361 phases in Korea to obtain the predicted value for the soil specific factors. The predicted values ​​ranged from 35 - 73 kg ha^-1, with 92 very suitable areas, 487 suitable areas, 421 possible areas, and 361 not suitable areas.

The soil suitability grades map of bracken in Korea. Based on the relationship value between the detailed soil characteristics and yield of bracken through a soil survey on the yield and the bracken cultivation fields.