Pustaka Ilmiah Universitas Padjadjaran

Abstrak

Effects Of Steel Slag And Bokashi On Physical Properties Of Volcanic Ash Soils

Volcanic ash soils have P retention that 85% or more, made the P availabity is one of the main problem of this soils. Ameliorants iSteel slag as silicate material has a high negative charge can be given to volcanic ash soils to and bokashi of husk were combined to be given to volcanic ash soils to Volcanic ash soil can refer to any soil that was derived from tephras or other pyroclastics materials (The Third Division of Soils, 1973). Further, Soil Survey Staff (1990) classified it as Andisol if fulfills the requirements of andic soil properties: the organic carbon is less than 25%, bulk density is than 0.9 gcm-3 or less, phosphate retention / P-retention is 85% or more, and Al + ½ Fe with ammonium oxalate 2% or more. Among these properties, the phosphate retention that more than 85% is a serious problem. Phosphorus availablity is therefore very limited. Fertilization of P will never be effective due to the P fertilizer will immediately be retained by soil. Egawa (1977) informed that only ten percent of P fertilezer will be available for plants.