RESEARCH STATUS QUO OF IMPACT FACTORS OF SOIL CARBON STORAGE

The dynamic balance of soil carbon pool is an important study field of soil fertility conservation and improvement, which affect directly crop productivity and soil fertility. In this paper, it is discussed that the effects of soil property, temperature and precipitation change, atmospheric CO 2 concentration increase and anthropogenic agricultural activities on soil carbon storage. There could exist a positive relationship between soil texture and soil organic carbon content, hence, changes in soil carbon storage could be estimated by analyzing soil texture, soil microorganism and soil depth. Climate change and land use/land cover changes are the most important causes that result in the change of soil carbon storage. Changes in temperature and precipitation will impact plant productivity, litterfall rate and humus respiration so that soil organic carbon storage decreases or increases. However, vegetation productivity and soil respiration have acclimatization role to warming. Enhancement of atmospheric CO 2 concentration will change utilizing efficiency of resources and carbon cycle ratio. So observation, experiments and modeling are very important direction to research controlling factors and mechanisms of soil organic carbon storage. Human activities led to more serious influence on soil carbon storage and flux than natural change. Land use change and deforestation emitted a lot of carbon to atmosphere from soil. Conversion from natural to agricultural land use, especially to cropland, leads to a rapid depletion of the soil organic carbon pool. Agricultural practices have also contributed to the depletion of soil organic carbon pool including drainage of wetlands, plowing and other forms of soil disturbance, inadequate management of soil fertility, tillage and excessive use of chemicals. Options for enhancing carbon pool in soil and ecosystems include reducing emissions and increasing soil organic carbon content and retention time of soil carbon. In order to better understand terrestrial ecosystem carbon cycle change, studies of the interaction relation among climate change, land use change and soil carbon cycle should be carried out.