阿克苏地区不同土地利用方式对土壤有机碳的影响

Effects of Different Land Use Patterns on Soil Organic Carbon in Aksu Area

【目的】研究新疆阿克苏地区农田或荒地改建为果园亦或果农间作后对土壤有机碳的影响。【方法】在阿克苏地区采集单作小麦、枣麦间作、单作枣园、荒地单作枣园、撂荒地等5种典型土地利用方式的土壤,测定有机碳含量并估算其碳储量。【结果】由农田更替为果园及果农间作后,提高了各层土壤有机碳含量,其中0~40 cm土层各层土壤有机碳均显著提高(P<0.05)。由荒地改建为果园后,0~10、10~20、20~30和60~80 cm土层土壤有机碳均有显著提高(P<0.05)。0~100 cm土层土壤有机碳储量范围2.21~14.31 t/hm2,垂直分布看,0~40 cm土层是有机碳储存的主要土层(份额比>56.9%),随深度增加而减少。不同土地利用方式下各土层土壤有机碳含量及碳储量均表现为枣麦间作>单作枣园>单作小麦>荒地单作枣园>撂荒地。【结论】阿克苏地区农田或荒地改建为果园或果农间后,均有利于土壤有机碳的提高。枣麦间作系统与其他土地利用方式相比具有较高的固碳潜力。

【Objective】To reveal the effects of the conversion of farmland or wasteland to orchard or agroforestry on soil organic carbon in the Aksu region of Xinjiang.【Method】In the Aksu area,the soils of five typical land use types such as sole wheat,jujube wheat intercropping,sole jujube,sole jujube in wasteland,and wasteland were collected to determine the soil organic carbon content and estimate its carbon storage.【Result】The results showed that the conversion of farmland to orchard or agroforestry increased soil organic carbon concentrations and the organic carbon content in each layer of 0-40 cm soil layer increased significantly(P<0.05).After the transition from wasteland to orchard,the soil organic carbon in soil layers in 0-10,10-20,20-30 and 60-80 cm depths was all increased significantly(P<0.05).The soil organic carbon storage ranged from 2.21 to 14.31 t/hm2 in the 0-100 cm soil layer.According to the vertical distribution,the 0-40 cm soil layer was the main soil layer for organic carbon storage(the percentage 56.9%),which decreased with the increase of soil depth.The soil organic carbon content and storage in different soil layers under different land use patterns were all shown as follows:Jujube wheat intercropping>Sole jujube>Sole wheat>Sole jujube in wasteland>Wasteland.【Conclusion】It was found that the conversion of farmland or wasteland to orchard or agroforestry increased soil organic carbon concentrations and storage.Compared with other land use patterns,the jujube wheat intercropping system had higher carbon sequestration potential.