Nutrient uptake and leaching under different fertilizer treatment for corn and potato growth in volcanic ash soil

摘要

The purpose of this study was focused on understanding of uptake of nutrients by plants, the behaviors of nutrients in soil and the possibility of leaching loss when N fertilizer (urea) and mature compost were applied. Lysimeters (volume 0.15 m~3, diameter 62 cm, height 62.8 cm) were installed for collecting leachate in the Jeju volcanic ash soils. Lysimeter study consisted of thirteen treatments: fallow, fallow with weeding, cropping without fertilizer and compost, three N fertilizer soil surfaceapplications (16,32, and 64 kg/lOa), three N fertilizer and compost soil surface applications (16+800, 32+1600, and 64+ 3200 kg/lOa), two water dissolved N fertilizer applications (16 and 32 kg/lOa), and low and high plant densities. The growth of corn (preceding crop) and potatoes (succeeding crop) and leaching loss were determined during the experimental period. The amount of leachate from lysimeter was remarkably greater at bare conditions than at cropping conditions for corn and potatoes. The N content of plants (corn and potatoes) tended to increase as fertilizer rate increased. Fertilization of urea dissolved in water to soil was more efficient than surface fertilization for the growth, yield, and the N uptake N of corn and potatoes. There were no differences in dry matter yield of plants between medium and high N rates, but N, Ca, K and Mg concentrations of plants were higher at higher N rates. There were significant correlations between N uptake and each of Ca, K and Mg uptakes in corn and potatoes. Total N uptake by plants increased with increased N fertilizer and compost applications. Plants absorbed 54.9 percent of applied N at low N rate and 31.0 to 34.0 percent at high N rates. The proportion of N leaching losses was lower at low N rateand high plant density.