Response of nitrogen mineralization dynamics and biochemical properties to litter amendments to soils of a poplar plantation  

作　　者：Xiaomin Ge Shiping Deng Ling Zhu Yong Li Zhiyuan Jia Ye Tian Luozhong Tang 

机构地区：[1]Department of Silviculture, College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu 210037, People's Republic of China [2]Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078, USA [3]Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing, Jiangsu 210037, People's Republic of China

出　　处：《Journal of Forestry Research》2018年第4期913-922,共10页林业研究（英文版）

基　　金：funded by the International Science and Technology Cooperation Program of China(No.2011DFA30490);the National Basic Research Program of China(973Program)(No.2012CB416904);the National Natural Science Foundation of China(Nos.31170566 and 31370618);the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)

摘　　要：Understanding the impact of plant litters on soil nitrogen （N） dynamics could facilitate development of management strategies that promote plantation ecosystem function. Our objective was to evaluate the effects of different litter types on N mineralization and availability, microbial biomass, and activities of L-asparaginase and odiphenol oxidase （o-DPO） in soils of a poplar （Populus deltoides） plantation through 24 weeks of incubation experiments. The tested litters included foliage （F）, branch （B）, or root （R） of poplar trees, and understory vegetation （U） or a mixture of F, B, and U （M）. Litter amendments led to rapid N immobilization during the first 4 weeks of incubation, while net N mineralization was detected in all tested soils from 6 to 24 weeks of incubation, with zero-order reaction rate constants （k） ranging from 7.7 to 9.6 mg N released kg-1 soil wk-1. Moreover, litter addition led to increased （C） 49-128% and increased microbial biomass carbon MBC：MBN ratio by 5-92%, strengthened activities of L-aspaxaginase and o-DPO by 14-74%; Up to about 37 kg N ha-1 net increase in mineralized N in litter added soils during 24 weeks of incubation suggests that adequate poplar and understory litter management could lead to reduced inputs while facilitate sustainable and economic viable plantation production.Understanding the impact of plant litters on soil nitrogen （N） dynamics could facilitate development of management strategies that promote plantation ecosystem function. Our objective was to evaluate the effects of different litter types on N mineralization and availability, microbial biomass, and activities of L-asparaginase and odiphenol oxidase （o-DPO） in soils of a poplar （Populus deltoides） plantation through 24 weeks of incubation experiments. The tested litters included foliage （F）, branch （B）, or root （R） of poplar trees, and understory vegetation （U） or a mixture of F, B, and U （M）. Litter amendments led to rapid N immobilization during the first 4 weeks of incubation, while net N mineralization was detected in all tested soils from 6 to 24 weeks of incubation, with zero-order reaction rate constants （k） ranging from 7.7 to 9.6 mg N released kg-1 soil wk-1. Moreover, litter addition led to increased （C） 49-128% and increased microbial biomass carbon MBC：MBN ratio by 5-92%, strengthened activities of L-aspaxaginase and o-DPO by 14-74%; Up to about 37 kg N ha-1 net increase in mineralized N in litter added soils during 24 weeks of incubation suggests that adequate poplar and understory litter management could lead to reduced inputs while facilitate sustainable and economic viable plantation production.

关 键 词：Plant litter Nitrogen mineralization Soilmicrobial biomass L-ASPARAGINASE o-diphenol oxidase 

分 类 号：S714[农业科学—林学]