模拟大气氮沉降及短期氮沉降恢复对森林土壤酸化及养分的影响  

Effects of Stimulated Atmospheric Nitrogen Deposition and Its Recovery on Soil Acidification and Nutrient

作　　者：王强[1] 

机构地区：[1]萍乡高等专科学校,江西萍乡337000

出　　处：《萍乡高等专科学校学报》2009年第6期61-69,共9页Journal of Pingxiang College

摘　　要：通过野外模拟试验,研究氮沉降增加以及短期氮沉降恢复对杉木人工林土壤物理性质、pH值、NH4+-N、NO3--N、交换性钙、镁的影响。试验设计为5种处理,分别为N0(0kg·hm-2·a-1)、N1(60kg·hm-2·a-1)、N2(120kg·hm-2·a-1)、N3(240kg·hm-2·a-1)、Nr(氮沉降恢复),每个处理重复3次。以尿素[CO(NH2)2]作为氮源,每月以溶液方式对林地进行喷施。通过3年的处理后发现,氮沉降使土壤容重降低;0-20cm土层pH值出现短期的突增,而20-60cm则随氮沉降量的增大其酸化程度也越大;0-40cm土层中土壤NH4+-N含量从高到低的顺序比较为:N3>N2>N0>N1;40-60cm土层为:N3>N2>N1>N0,;土层中NO3--N含量从高到低的顺序为:N3>N2>N0>N1。氮沉降促进了土壤交换性钙和镁的增加。短期的氮沉降恢复过程中,土壤NH4+-N和NO3—N出现了显著的恢复特征;而土壤容重、pH值、交换性钙、镁也出现了一些恢复现象,但其特征并不显著。A field experiment was set to study the effects of increased nitrogen deposition on soil physical properties、pH、NH4＋-N、NO3--N、exchangeable Ca2＋ and Mg2＋.Treatments were designed as N0（0 kg·hm-2·a-1）、N1（60kg·hm-2·a-1）、N2（120kg·hm-2·a-1）、N3（240kg·hm-2·a-1）、Nr（resume of nitrogen deposition）,with three replicates in each treatment. Urea was used as the source of nitrogen and its solutions were sprayed on the forest ground each month for three years. The results showed that the soil bulk density was declining by the nitrogen deposition; the soil layer of 0-20cm had an increase on the pH in a short time, the layer of 20-60cm was acidified more obviously with more nitrogen deposition; The content of NH4＋-N in 0-40cm with the different nitrogen deposition was： N3N2N0N1,40-60cm was N3N2N1N0;NO3--N was： N3 N2N0N1. Nitrogen deposition caused the increase of soil exchangeable Ca2＋ and Mg2＋.In the recovery of nitrogen deposition for a short-time, the soil NH4＋-N and NO3--N had an noticeable character, the soil pH、exchangeable Ca2＋ and Mg2＋ had some recovery phenomena, but not noticeable.

关 键 词：氮沉降 杉木人工林 土壤酸化 交换性钙、镁 

分 类 号：S714[农业科学—林学]