Effects of zeolite application on nitrate and ammonium retention of a loamy soil under saturated conditions

摘要: Nitrogen (N) loss from irrigated cropland, especially in rice paddies, results low N-use efficiency and groundwater contamination. Soil conditions that increase ammonium nitrate ion retention alleviate these problems. Clinoptilolite, a naturally occurring zeolite with high-exchange capacity, may be used to absorb retard excess leaching of nitrate. The objectives this research were determine the effects different rates Ca–K-zeolite application (0, 2, 4, 8 g/kg soil) on pore water velocity applied as fertiliser loam soil at rate 350 kg N/ha under saturated similar paddy. indicate applications 4 by 35% 74%, respectively. maximum relative concentration (c/co) for breakthrough curve volume about 0.5 was reduced 15% soil. When applying 40 cm water, leached 75% 63% total surface soil, Due high exchange capacity zeolite, 2 g/kg is enough sites order prevent its inflow water. 43% compared control treatment. relationship between hydrodynamic dispersion coefficient (D) (v) not linear it correlated squared velocity. D v2 dependent linearly increased rate.