Carbon Sequestration Potential And Effect On Dry Farmland In Guanzhong Area

Recently, soil carbon sequestration potential and CO2emission in conservation tillagehave been the international and domestic research hotspot. Based upon the long-termexperimental of wheat-fallow/wheat-soybean/wheat-maize rotations in shannxi province.This paper discussed SOC content, SOC storage content, soil CO2emission regulation and therelationship between soil CO2emission and impact factors, cropping carbon absporation, andbase on these, estimated soil carbon sequestration potential. The result showed that:Soil organic carbon content was decreased with deeper layer of three rotation modes.During the first rotation period, soil organic carbon content was increased with the extensionof rotation time under wheat-fallow rotation. The SOC storage content contained between400and900kg·m-2C, but changed slowly.Soil CO2emission both showed one perk between April18and May8,2012underwheat-fallow rotation and wheat-maize rotation during the time from June2012to June2013.Three modes had same variation from June2011to June2012, the relationship between soilCO2emission and soil factors showed negative correlation among three modes, partstreatments showed significant correlation with soil water content under wheat-fallow rotation;With limited treatment showed conspicuous correlation under wheat-soybean rotation;showed significant correlation with soil water content of parts treatment under wheat-maizerotation. From June2012to June2013, soil CO2emission and water content showed negativecorrelation, but with soil temperature showed positive correlation and parts treatments showedsignificant correlation under wheat-fallow rotation; soil CO2emission and experimentalfactors showed positive correlation and showed conspicuous correlation with soil temperatureunder wheat-soybean rotation and wheat-maize rotation.Crop carbon sequestration was higher than soil carbon sequestration, total carbonsequestration were22.09kg·m-2C、15.01kg·m-2C、21.47kg·m-2C, respectively. The highestcarbon sequestration rate was121.12%、55.20%、70.85%, respectively.Total soil CO2emission was wheat-maize rotation>wheat-fallow rotation>wheat-soybean rotation, the amount of these were111.38kg·m-2C、101.09kg·m-2C、99.96kg·m-2C, respectively.The actual carbon sequestration potential under three rotation modes was wheat-fallow rotation wheat-soybean rotation> wheat-maize rotation, the amounts of these were-79kg·m-2C、-84.95kg·m-2C、-107.52kg·m-2C.