中国农业科学Issue(9)：1764-1773,10.DOI:10.3864/j.issn.0578-1752.2015.09.10
耕作措施对东北黑土微生物呼吸的影响
Effect of Conservation Tillage on Microbial Respiration of Black Soil
摘要
Abstract
Objective] In this study, soil microbial activity and biomass carbon under 13-year conservation tillage (no-till) were assessed in a black soil agro-ecosystem in northeast China in order to determine the effect of tillage treatment on soil organic carbon and soil microbial biomass, which would provide a theoretical basis for valuing the ‘sink’ or ‘source’ function of soil carbon pool.[Method] The present study was conducted as part of a long term tillage experiment on the continuous maize (Zea mays L.), tillage treatments consisted of no-tillage (NT), and mouldboard plough (MP). The NT treatment had no soil disturbance except planting, crop residues were left on soil surface after harvest. The MP treatment included one fall mouldboard plough (about 15 cm in depth) after maize harvest, one disking (7.5 to 10 cm in depth) in spring and field cultivation (ridging in June). Soil respiration without roots represented soil microbial respiration, which was measured biweekly from 14 June 2012 to 25 September 2013 using LI-8100 automated soil CO2 flux system (LI-COR Inc., Lincoln, NE, USA), soil microbial biomass and the number of colony forming units of bacteria (cfub), fungi (cfuf), and actinomyces (cfua) were measured during the soil microbial respiration was the highest.[Result] It was found that the range of soil microbial respiration was 0.42-3.35μmolCO2·m-2·s-1under NT and 0.48-3.24μmolCO2·m-2·s-1under MP during growing season, the average soil microbial respiration was similar between NT and MP (8.8%), while the total soil CO2 emission during the growing season under NT was 10.0% (2012) and 4.3% (2013) higher than MP (P<0.05). The cfub, cfuf and cfua at 0-5 cm under NT were significantly higher by 125.7%, 112.4%, and 53.3% than MP, respectively, and cfuf at 5-10 cm, 10-20 cm and 20-30 cm under NT was 105.3%, 159.4% and 114.7% higher than MP, and. Soil temperature at 0-5 cm and 5-10 cm under NT were 2.8% and 5.8% higher than MP in June, respectively. Soil microbial respiration showed a significant seasonal pattern similar to soil temperature, the highest rate occurred in summer (July or August), followed by spring and fall. Although tillage treatment did not influence the seasonal dynamic of soil microbial respiration, the highest rate of soil microbial respiration under MP was a half-month behind the NT. There was a significant exponential relationship between soil microbial respiration and soil temperature at 5 cm and 10 cm soil depth, exponential model at 10 cm produced better fitness than 5 cm, the temperature sensitivity (Q10) at 5 cm under NT was 10.8% higher than MP. The combined exponential model indicated that soil temperature and water content (SWC) could jointly explain 65% (MP) and 81% (NT) of variation in soil microbial respiration.[Conclusion]The results suggested that the soil microbial activity at surface soil (0-5 cm) under NT was higher than MP, which is contributed to the higher SOC content under NT, the increase of the weighted average of SOC at 0-30 cm suggested that NT appears to be a better tillage practice to SOC sequestration in Northeast China.关键词
土壤微生物呼吸/土壤微生物数量/免耕/黑土Key words
soil microbial respiration/soil microbial quantity/no-tillage/black soil引用本文复制引用
贾淑霞,孙冰洁,梁爱珍,陈学文,张士秀,魏守才,刘四义,陈升龙,张晓平..耕作措施对东北黑土微生物呼吸的影响[J].中国农业科学,2015,(9):1764-1773,10.基金项目
国家自然科学基金（41101241，41201217）、中国科学院黑土区农业生态重点实验室开放基金 （）
