长期施肥对绿洲农田土壤有机碳和无机碳的影响

以中国科学院阜康荒漠生态站的绿洲农田养分循环长期定位试验（始于1990年）为研究平台，研究了无施肥处理（CK）、单施化肥处理（NPK）、有机/无机配施处理（NPKM）和秸秆还田处理（NPKS）下，土壤无机碳(SIC)和有机碳(SOC)在剖面和各施肥年限的含量变化特征及其影响。结果表明：施肥、剖面层次和施肥年限对SOC与SIC含量变化影响显著(P<0.01)。在各施肥处理中，与CK相比，NPK、NPKM和NPKS的SOC与SIC含量明显增加(P<0.05），并且有机/无机肥配施模式下的SIC含量显著高于单施化肥模式；在剖面层次间，SIC含量从0～20 cm 的9.12 g/kg 增加到40～60 cm 的9.94 g/kg，而SOC变化趋势与之相反。表明合理施肥能够增加土壤表层有机碳含量，有机/无机配施会使耕层以下土壤无机碳增加。

Effect of Long-term Fertilization on Soil Organic Carbon and Soil Inorganic Carbon in Oasis Cropland

In this study, the Fukang Station for Desert Ecological Research, Chinese Academy Sciences, was regarded as a platform to lucubrate the dynamic change of soil carbon content, soil carbon sequestration potential and long term oasis agricultural nutrient cycling, including the distribution of soil inorganic carbon content (SIC) and organic carbon content (SOC) along soil profile and at different fertilization time under the different soil fertilization treatments, such as the treatment without fertilization (CK), single fertilizer application (NPK), and fertilization treatment with straw (S) in arid area. The results showed that the fertilizer application, soil depth and fertilization time affected significantly the SOC content and SIC content in soil (P<0.01).Compared with CK, the SOC content and SIC content under NPK, M and S were significantly increased (P<0.05),and the SIC content under the organic/inorganic fertilizing combination (M) was significantly higher than that under chemical fertilizer application. The average SIC content was increased from 9.12 g/kg in soil layer of 0-20 cm in depth to 9.17 g/kg in soil layer of 20-40 cm and to 9.94 g/kg in soil layer of 40-60 cm respectively, but the SOC content was contrary. These revealed that the rational fertilization could increase the organic carbon content in topsoil, and the carbon sequestration in soil could be increased under organic/inorganic fertilizing combination (M).