Soil organic carbon dynamics under long-term fertilizations in arable land of northern China

• 作 者: W.J.Zhang X.J.Wang M.G.Xu S.M.Huang H.Liu C.Peng
• 机 构: Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultura
• 出 处: 2010年北京土壤学会学术年会
• 发表日期: 2010年7期

　　Soil carbon sequestration is a complex process influenced by agricultural practices, climate and soil conditions.This paper reports a study of long-term fertilization impacts on soil organic carbon (SOC) dynamic from six long-term experiments.The experiment sites are located from warm-temperate zone with a double-cropping system of corn (Zea mays L.)-wheat (Triticum Aestivium L.) rotation, to mild-temperate zones with mono-cropping systems of continuous corn, or a three-year rotation of corn-wheat-wheat.Mineral fertilizer applications result in an increasing trend in SOC except in the arid and semi-arid areas with the mono-cropping systems.Additional manure application is important to maintain SOC level in the arid and semi-arid areas.Carbon conversion rate is significant lower in the warmtemperate zone with double cropping system (6.8%-7.7%)than that in the mild-temperate areas with mono-cropping systems (15.8%-31.0%).The conversion rate is significantly correlated with annual precipitation and active accumulative temperature, i.e., higher conversion rate under lower precipitation and/or temperature conditions.Moreover, soil high in clay content has higher conversion rate than soils low in clay content.Soil carbon sequestration rate ranges from 0.07 to1.461 tha-1 year-1 in the upland of northern China.There is significantly linear correlation between soil carbon sequestration and carbon input at most sites, indicating that these soils are not carbon-saturated thus have potential to migrate more CO2 from atmosphere.