土壤呼吸作用和全球碳循环

土壤呼吸作用是全球碳循环中一个主要的流通途径 ,导致土壤碳以CO2 形式流向大气圈。全球土壤中碳贮存量的增加有助于缓和人为CO2 的进一步释放 ,而土壤CO2 的流失则显著地加剧大气CO2 的升高和增强温室效应。文章简单评述了土壤呼吸作用、大气CO2 升高、全球温度升高三者之间的关系 ,并提出 :改进的管理实践能减少农业土壤中CO2 净流失 ,增加有机碳贮存。减缓土壤呼吸作用的一项简单措施是减少土壤耕作。土壤扰动最小的耕作实践称为免耕作。实践证明 ,当实施免耕作时 ,土壤有机质的流失明显降低。

SOIL RESPIRATION AND CARBON CYCLE

The flux of carbon from soils to the atmosphere occurs primarily in the form of CO 2 ,and is the result of soil respiration The estimate of the magnitude of their flux is approximately 75 Pg C/a, which makes soil respiration one of the major pathways of flux in the global carbon cycle Increased storage of carbon in world soils could help offset further anthropogenic emissions of CO 2 , whereas a release could significantly exacerbate the increase of atmospheric CO 2 and reinforce the greenhouse\|warming effect.This paper provides a brief scientific review for the public on changes in soil respiration that may contribute to the rise in CO 2 in Earth's atmosphere Improved management practices can reduce the net CO 2 emissions from agricultural soils and stabilize and /or increase the storage of soil organic carbon Management options that contribute to reducing soil respiration include reducing tillage practices and increasing cropping intensity The tillage practice with least soil disturbance is no\|till The loss of soil organic matter is lower when no\|till agriculture is practiced