Consist Of Soil Respiration Of Winter Wheat And Summer Corn In The Farmlands At The China North Plain

Farmland ecosystem, as an important part of global terrestrial ecosystem, plays an irreplaceable role in global climate change and carbon cycle. Compared to other ecosystems, soil respiration is easier influenced by artificial factors. What’s worse, this phenomenon has become more serious than before, which makes the study of soil respiration of farmland become necessity and complexity, and increases the difficulties to estimate the total amount of CO2from agricultural soils. Therefore, studies on soil respiration and its components to conjecture the total amount of CO2from soil to atmosphere accurately, makes great sense for researching on global warming and finding its impact on human living environment in the future.Based on high yield farmland in the North China Plain, this study using winter wheat-summer maize rotation system as the research object, which sets conventional processing and optimization two treatment, and using the means of (root respiration and soil microbial respiration) observes the exchange amount of CO2and the component of soil breath whole year to emphasis the exchanges amount of carbon between different components of soil breath, then to afford proof for exploring a reasonable method of reducing emission. The main results are as follows:The trend of changes in emission of CO2from soil respiration, between different treatments in winter wheat-summer maize rotation system annual, is basically the same. Soil respiration and total carbon emissions:conventional treatment> optimization, the mount of soil respiration and carbon emissions of wheat season<the mount of soil respiration and carbon emissions of maize season.There was significant correlation between soil temperature in10cm depth and soil respiration, and it can be fitted by exponential equation (y=aehx), which can normally explained about58%-87%variations of soil respiration. In winter wheat, the Q10for each treatments was2.60(conventional treatment),2.85(optimization treatment). In summer corn, the Q10for each treatments was2.17(conventional treatment),2.86(optimization treatment).In test of root exclusion method, soil respiration emission:conventional treatment> optimization treatment,2.74t C ha-1and2.38t C ha-1. CO2reached the maximum at anthesis, reached179±16.80mg C m-2h-1; minimum occurs in winter,12.20±0.47mg C m-2h-1. In the conventional processing and optimization, the factors contributions to soil respiration:root respiration<soil organism respiration. Compared to the conventional treatment, optimization reduces the emission amount of CO2by13.1%.In comparing test of root exclusion method and root biomass regression method on summer maize, soil respiration emission:root respiration> soil microbial respiration,3.32t C ha-1and2.84t C ha-1. Compared with the conventional treatment, the process of optimization reduces CO2emissions by14.5%.Total soil respiration in summer maize achieve significant peak after fertilization and irrigation, and the minimum occurred at maturing stage. The differences of soil respiration between minimum and maximum were smaller:158.32±4.47mg C m-2h-1,66.01±5.12mg C m-2h-1. According to division root respiration and soil microbial respiration to soil respiration is root respiration<soil microbial respiration. Conventional treatment of root respiration to the total soil respiration rate was30%, the optimizing process was28%. In root biomass regression method, contributions to soil respiration is root respiration<soil microorganism respiration. In soil respiration of conventional processing, root respiration station occupied44%, and optimization processing accounted for42.3%.