首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Long-term tillage and crop rotation effects on microbial biomass and C and N mineralization in a Brazilian Oxisol
Authors:Elcio L Balota  Arnaldo Colozzi Filho  Diva S Andrade  Richard P Dick
Institution:

a Soil Science Department, Instituto Agronômico do Paraná (IAPAR), Caixa Postal 481, 86001-970, Londrina, PR, Brazil

b Crop & Soil Science Department, Oregon State University, Corvallis, OR 97331-7306, USA

Abstract:Crop rotation and tillage impact microbial C dynamics, which are important for sequestering C to offset global climate change and to promote sustainable crop production. Little information is available for these processes in tropical/subtropical agroecosystems, which cover vast areas of terrestrial ecosystems. Consequently, a study of crop rotation in combination with no tillage (NT) and conventional tillage (CT) systems was conducted on an Oxisol (Typic Haplorthox) in an experiment established in 1976 at Londrina, Brazil. Soil samples were taken at 0–50, 50–100 and 100–200 mm depths in August 1997 and 1998 and evaluated for microbial biomass carbon (MBC) and mineralizable C and N. There were few differences due to crop rotation, however there were significant differences due to tillage. No tillage systems increased total C by 45%, microbial biomass by 83% and MBC:total C ratio by 23% at 0–50 mm depth over CT. C and N mineralization increased 74% with NT compared to CT systems for the 0–200 mm depth. Under NT, the metabolic quotient (CO2 evolved per unit of MBC) decreased by 32% averaged across soil depths, which suggests CT produced a microbial pool that was more metabolically active than under NT systems. These soil microbial properties were shown to be sensitive indicators of long-term tillage management under tropical conditions.
Keywords:Basal respiration  Microbial biomass  Carbon and nitrogen mineralization  Tillage systems  Crop rotations
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号