中文摘要：

在温室内对1年生盆栽杉木幼苗进行模拟试验，以研究氮沉降对土壤酸化和土壤盐基离子含量的影响．以NH4NO3为外加氮源，设置5种处理，分别为N0（对照，0gm^-2a^-1，以N计，下同）、N1（6gm^-2a^-2）、N2（12gm^-2a^-2）、N3（24gm^-2a^-2）和N4（48gm^-2a^-2），每处理重复6次．经过18个月的处理后，对盆栽土壤进行取样分析．结果显示，随着氮沉降量的增加，土壤pH值逐渐下降，而土壤交换性酸度和交换性Al^3＋则不断增加．经N1、N2、N3和N4处理后，土壤交换性盐基总量分别下降6．29％、8．94％、10．07％和10．38％，土壤阳离子交换量分别下降5．07％、7．27％、8．53％和8．83％．随氮沉降量的增加，土壤NH4^＋-N、NO3^--N含量逐渐增加．低氮处理（N1、N2）使土壤交换性K^＋、Ca^2＋、Mg^2＋含量增加，而高氮处理（N3、N4）则呈相反趋势．氮沉降由于增加了土壤活性氮的含量，加速了土壤酸化，从而导致了盐基离子的淋失．图3表3参41

英文摘要：

In order to study the effects of nitrogen deposition on soil acidification and soil base cations, a pot experiment was conducted in greenhouse. The treatments were designed as NO （control）, N1, N2, N3 and N4 at the doses of 0, 6, 12, 24 and 48 g N m-2 a-1, respectively, with six replicates in each treatment. NH4NO3 was used as the source of nitrogen. The results showed that soil pH decreased with increasing nitrogen deposition, but soil total exchangeable acid （TEA） and exchangeable aluminum （EA） increased after incubating of 18 months. The total base cations in soils with N1, N2, N3 and N4 treatments decreased by 6.29%, 8.94%, 10.07% and 10.38%, respectively, and soil cation exchange capacity （CEC） decreased by 5.07%, 7.27%, 8.53% and 8.83%, respectively. The contents of NH4＋-N and NO3--N in soil increased with increasing nitrogen deposition. Low nitrogen deposition （Nl, N2） accelerated increasing of soil exchangeable K^＋, Ca2＋ and Mg2＋, but high nitrogen deposition （N3, N4） was opposite. Because increasing of soil active nitrogen, nitrogen deposition accelerated soil acidification, accordingly which resulted in leaching of soil base cations. Fig 3, Tab 3, Ref41