摘要
本文用荷兰8种表土测试不同温度下0.01molL^(-1)CaCl_2提取液和淋滤液中N素各形态。试验结果表明温度对NO_3^--N提取量和淋滤量无影响,但对NH_4^+-N、可溶性总N和还原态N影响显著;可溶性有机态N的释放服从一级动力学方程:N_t=N_0(1-e^(-kt)),非线性最小二乘法能满意地拟合动力学实验结果。测定0.01molL^(-1)CaCl_2提取液中的可溶性有机态N对预测土壤N素矿化、合理推荐施肥及防止N素污染可能是一个很有前途的指标。
Eight Dutch surface soils were used in this study to analyse different N fractions in 0.01 molL^(-1) CaCl_2 extracts and percolates at different temperatures.The resulcs obtained showed that:(1) The temperature of 0.01 molL^(-1) CaCl_2 extracting and percolating solution had no influence on amount of No_3^- -N,the extractability of other N fractions (NH_4^+ -N,total soluble N and reduced N),however,was evidently affected by the temperature in 0.01 molL^(-1) CaCl_2 solution.The hydrolysis of organic N was the predominant reason for this influence.(2) The release of organic soluble N obeyed the first order kinetics.A nonlinear least square method could bestfit the experimental data into the model N_t=N_0(1——e^(-kt))with Rsquared being higher than 0.99.(3) The kinetic values No were highly consistent with the soluble reduced N in extraction experiment.The 0.01 molL^(-1) CaCl_2 solution extracted and released the labile organic N fraction.The determination of soluble org anic N in 0.01 molL^(-1) CaCl_2 solution looked promising as a property for prediction of N mineralization,N fertilization and N pollution.
出处
《土壤学报》
CAS
CSCD
北大核心
1991年第1期32-39,共8页
Acta Pedologica Sinica
