不同年限旱砂田土壤团聚体及其有机碳分布特征

发布时间：2018-06-18 23:46

本文选题：旱砂田 + 土壤团聚体　；参考：《应用生态学报》2017年05期

【摘要】：以长期定位试验5、10、15、20、30年旱砂田为研究对象,研究了不同年限旱砂田土壤团聚体及其有机碳的分布特征.结果表明:旱砂田土壤团聚体含量随粒级减小表现出"降-升-降"的变化趋势,10年以内旱砂田以5 mm粒级团聚体为主,15年以上旱砂田以0.05~0.25 mm粒级团聚体为主,0.25 mm团聚体含量(R_(0.25))和团聚体平均质量直径(MWD)均随着覆砂年限的延长而减小.不同年限旱砂田土壤团聚体有机碳含量随团聚体粒级减小而增加,各粒级土壤团聚体有机碳含量、团聚体对有机碳的贡献率及团聚体有机碳储量均随着覆砂年限的延长和土层的加深而降低,1 mm粒级团聚体有机碳对长期旱砂田有机碳变化响应敏感.10、15、20、30年较5年旱砂田团聚体有机碳储量在0~10 cm土层分别降低了8.0%、24.4%、27.5%和31.4%,10~20 cm土层分别降低了1.4%、15.8%、19.4%和21.8%.综上所述,旱砂田土壤固碳能力随种植年限延长而降低,需加强15年以上旱砂田的土壤培肥工作.
[Abstract]:The soil aggregates and their organic carbon distribution in dry sandy fields with different years were studied in the long-term location experiment (5 ~ 10 ~ 15 ~ (20) and dry sandy fields for 30 years. The results showed that the soil aggregate content in dry sandy field showed a tendency of "down-rise-descending" with grain size decreasing. Within 10 years, 5 mm grain aggregate was dominant in dry sandy field, and 0. 05 ~ 0. 25 mm agglomerate was dominant in dry sand field over 15 years. Mm aggregate content and mean mass diameter of aggregate decreased with the increase of sand age. The organic carbon content of soil aggregates increased with the decrease of aggregate grain size, and the organic carbon content of soil aggregates increased with the decrease of grain size of aggregates in dry sand fields in different years. The contribution rate of aggregates to organic carbon and the accumulation of organic carbon in aggregates decreased with the prolongation of sand cover years and the deepening of soil layer. The sensitivity of organic carbon of 1 mm grain aggregate to organic carbon change in dry sandy field was sensitive to the change of organic carbon in long-term dry sand field. The drought of 30 years was more than that of 5 years. In the 0 ~ 10 cm soil layer, the organic carbon storage of sand aggregate decreased by 8.0% and 24.44%, respectively, and decreased by 1.4% and 21.8%, respectively, in 10 ~ 20 cm soil layer. To sum up, soil carbon sequestration capacity of dry sandy field decreased with the extension of planting years, and soil fertilization work of dry sand field should be strengthened for more than 15 years.
【作者单位】：甘肃省农业科学院蔬菜研究所;甘肃省农业科学院;甘肃省农业科学院土壤肥料与节水农业研究所;
【基金】：甘肃省农业科学院中青年基金项目(2014GAAS26) 国家西甜瓜产业技术体系(CARS-26-20) 农业部西北地区蔬菜科学观测实验站项目(2015-A2621-620321-G1203-066)资助~~
【分类号】：S153.6

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