摘要
以亚热带毛竹林为研究对象,以长江三角洲地区实际氮沉降量40 kg/(hm^2·a)为参照,设置2种形态(铵态氮(NH 4 Cl)和硝态氮(KNO 3))和3种水平(对照、低氮和高氮(0,40,120 kg/(hm^2·a))的氮添加试验。结果表明:(1)氮添加显著降低了土壤pH,不同氮水平和形态对pH均有显著影响(P=0.001和P=0.010);(2)高水平氮处理下,硝态氮处理的土壤NO 3^--N和DON含量分别高于铵态氮处理的40.06%和50.10%,土壤NH 4^+-N含量低于铵态氮处理的12.33%,在同一氮形态下,高氮处理的土壤NO 3^--N和DON含量分别高于低氮处理的47.12%和78.12%,土壤NH 4^+-N含量低于低氮处理的24.24%。说明氮水平和形态均对土壤NH 4^+-N、NO 3^--N和DON含量有显著影响(P<0.05);(3)与对照相比,高水平氮处理下土壤脲酶和蔗糖酶活性分别提高了14.16%和8.11%,氮形态对土壤脲酶和蔗糖酶活性没有显著影响。氮水平和形态对过氧化氢酶活性均无显著影响(P>0.05);(4)土壤脲酶、蔗糖酶和过氧化氢酶活性均呈现显著的季节变化,脲酶和蔗糖酶活性夏季高,冬季低,春秋居中,过氧化氢酶则秋冬季节较高。氮添加没有改变酶活性的季节分异规律。通过Pearson分析发现,土壤酶活性(脲酶、蔗糖酶和过氧化氢酶)与土壤生化特性显著相关(P<0.05)。氮水平和形态对土壤生化特性和酶活性的影响存在一定差异,研究结果可为氮沉降背景下亚热带毛竹林的管理提供理论依据。
Taking the subtropical moso bamboo(Phyllostachys edulis)forest as research object,the soil biochemical properties and enzymes activities were studied using two forms(NH 4 Cl and KNO 3)and three levels(0,40 and 120 kg/(hm^2·a).The results showed that:(1)The nitrogen input reduces the pH of soil,different forms and levels had a significant effect on soil pH(P=0.001 and P=0.010);(2)Under high nitrogen treatment,nitrate nitrogen of soil NH 4^+-N、NO 3^--N and DON differ with ammonium nitrogen of 12.33%,40.06%and 50.10%.Under the same nitrogen form,high-N treatment of soil NH 4^+-N、NO 3^--N and DON differ with ammonium nitrogen of 24.24%,47.12%and 78.12%.Nitrogen forms and levels had significant effects on soil biochemical properties;(3)Compared with the CK,soil urease and invertase activities were increased by 14.16%and 8.11%under High-N treatment,and nitrogen forms had no significant effect on soil urease and invertase activities.Nitrogen levels and forms had no effect on catalase activity(P>0.05);(4)Soil enzyme activities(urease,inverse and catalase activities)showed significant seasonal variation in bamboo forest.The highest activities of urease and invertase were found in the summer and the lowest activities of urease and invertase were found in the winter.But the highest activities of catalase activity was found in the winter.However,inputs of extraneous N made little different on temporal variation.Through the Pearson method,Soil enzyme activities were significantly correlated with soil biochemical properties(P<0.05).The above results show that the effects of nitrogen levels and forms on soil biochemical properties and enzyme activities are different,which can provide a theoretical basis for the management of subtropical moso bamboo(Phyllostachys edulis)forest under the background of nitrogen deposition.
作者
陈向峰
刘娟
姜培坤
吴家森
周国模
李永夫
CHEN Xiangfeng;LIU Juan;JIANG Peikun;WU Jiasen;ZHOU Guomo;LI Yongfu(State Key Laboratory of Subtropical Silviculture,Lin’An,Zhejiang 311300;Zhejiang Provincial Key Laboratory of Carbon Cycling in Forest Ecosystems and Carbon Sequestration,Lin’An,Zhejiang 311300)
出处
《水土保持学报》
CSCD
北大核心
2020年第5期277-284,共8页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(31700540)
浙江省重点研发计划项目(2019C02008-03)。
关键词
氮水平
氮形态
毛竹林
生化特性
酶活性
N levels
N forms
moso bamboo(Phyllostachys edulis)forest
soil biochemical properties
enzyme activities
