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

This study was carried out in order to determine the Kiwi fruit (Actinidia deliciosa cv. Hayward) fertilization standards in Jeju. Soil chemical properties and mineral contents of leaves, and the amounts of fertilizers were investigated in 35 places of volcanic ash soils and in 15 places of non volcanic ash soils. Tests were made to provide the most resonable fertilizer recommendation for kiwi fruit based on soil analytical data and leaf mineral contents response to the NPK fertilizers. Average pH was 6.0, organic matter (OM) content was 113 g kg^-1, available P₂O₅ content was 288 mg kg^-1, and exchangeable K, Ca, and Mg were 1.61, 10.5, and 3.1 cmol_c kg^-1, respectively for volcanic ash soils. Also, Average pH was 5.7, organic matter (OM) content was 48.3 g kg^-1, available P₂O₅ content was 541 mg kg^-1, and exchangeable K, Ca, and Mg were 1.45, 6.6, and 2.2 cmol_c kg^-1, respectively for non volcanic ash soils in Jeju. Available phosphorus contents of volcanic ash soils, were lower than those of non volcanic ash soils. However, soil organic matter contents were higher than those of the optimun range. P and Mg contents of kiwi fruit leves were lower in comparison with a suitable standard leaf, but K and Ca contents were higher. The amounts of N, P₂O₅, and K₂O fertilizers applied to farmers' fields were N 22.4 kg 10a^-1, P₂O₅ 21.6 kg 10a^-1, and K₂O 18.3 kg 10a^-1 in volcanic ash soils. Those of non volcanic ash soils were 17.1 kg 10a^-1, 13.5 kg 10a^-1 and 13.3 kg 10a^-1. The Yield had no difference between the volcanic ash soils and non volcanic ash soils. The relationship between soil chemical properties and amounts of fertilizer use were observed. The soil organic matter contents werenegatively correlated with amounts of nitrogen fertilizers. Soil available phosphorus contents were negatively correlated with amounts of phosphate fertilizer. Also, Soil exchangeable potassium contents showed negative correlation with amount of potassium fertilizer. Recommended fertilizer amounts for N and P₂O₅ were determined by using the soil OM and available P₂O₅ contents. Recommended K₂O fertilizer were determined by exchangeable K contents in soils. Amounts of standard fertilization N-P₂O₅-K₂O fertilizer in volcanic ash soils were 16.5-16.5-11.1 kg/10a for kiwi fruit of 8 years or older, and 13.5-8.8-9.0 kg/10a in non volcanic ash soils.

N, P₂O₅, and K₂O standard fertilizer amount by tree ages in volcanic ash soils and non volcanic ash soils in Jeju.