氮添加与凋落物管理对华北落叶松人工林土壤化学性质的影响

Effects of Nitrogen Addition and Litter Management on Soil Chemical Properties of Larix principis-rupprechtii Plantation

本研究以阴山山地华北落叶松人工林为研究对象,分析氮添加与凋落物管理对表层土壤化学性质的影响,以期为加速凋落物分解和地力维持提供科学依据。采用两因素随机区组试验,氮添加水平为不施氮[0 kg/(hm^(2)·a)]、低氮[50 kg/(hm^(2)·a)]和高氮[100 kg/(hm^(2)·a)],凋落物管理方式为保持原状、堆积和搅拌。结果显示:(1)单独氮添加,随着添加量的增加,土壤pH显著下降,硝态氮含量显著升高;氮添加显著降低土壤有机质含量,低氮处理显著提高速效钾含量,高氮处理显著提高有效磷含量。(2)单独凋落物管理,堆积和搅拌可显著降低土壤pH,提高土壤硝态氮、有效磷含量;凋落物堆积处理显著降低表层土壤速效钾含量,凋落物搅拌处理显著提高表层土壤有机质、全氮、速效钾含量。(3)交互作用对表层土壤pH和有机质、全氮、硝态氮、有效磷、全钾、速效钾含量的影响显著。上述研究结果表明,氮添加可促进表层土壤中有机物的矿化,提高硝态氮、铵态氮和有效磷含量,搅拌处理可加速凋落物分解,提高土壤有机质、全氮和速效养分含量。因此,高氮+搅拌处理土壤全钾、有效磷、速效钾、硝态氮含量最高,对促进养分循环和维持地力平衡具有重要作用。

In the paper,the effects of nitrogen addition and litter management on soil chemical properties in surface soil of Larix principis-rupprechtii plantation in Yin Mountain were analyzed.This research aimed to provide scientific basis for accelerating litter decomposition and maintaining soil fertility.The two-factor randomized block experiment was conducted.The nitrogen addition levels were no nitrogen[0 kg/(hm^(2)·a)],low nitrogen[50 kg/(hm^(2)·a)]and high nitrogen[100 kg/(hm^(2)·a)].The litter management methods were remain,accumulation and mixing.The results showed that with the increase of nitrogen application rate,soil pH decreased significantly,while nitrate nitrogen content increased significantly.Nitrogen addition significantly reduced soil organic matter content,low nitrogen treatment significantly increased available potassium content,and high nitrogen treatment significantly increased available phosphorus content.Accumulation and mixing can significantly reduce soil pH and increase soil nitrate nitrogen and available phosphorus content.Accumulation significantly reduced the content of available potassium,and mixing significantly increased the content of organic matter,total nitrogen and available potassium.The interaction had significant effects on soil pH and contents of organic matter,total nitrogen,nitrate nitrogen,available phosphorus,total potassium and available potassium.This study showed that nitrogen addition can promote the mineralization of organic matter in soil,and increase the contents of nitrate nitrogen,ammonium nitrogen and available phosphorus.Mixing treatment can accelerate the decomposition of litter,and increase the contents of soil organic matter,total nitrogen and available nutrients.The contents of soil total potassium,available phosphorus,available potassium and nitrate nitrogen with high nitrogen and mixing treatment was the largest,which plays an important role in promote nutrient cycling and maintaining soil fertility balance.