Abstract:

【Objective】 To study the change characteristics of soil organic carbon content and its influencing factors of cultivated land in northern Xinjiang in the past 40 years.【Method】 Representative data were obtained by collecting data from the second soil survey in Xinjiang in 1980 and soil series survey data in 2014, such as variance analysis, correlation analysis, and regression analysis to combine total soil nitrogen, total phosphorus, pH, and climate with influencing factors such as the amount of agricultural chemical fertilizers, the overall trend and vertical change characteristics of the organic carbon content of different soil types in the two periods were compared and analyzed, and the natural and man-made driving factors affecting this change were discussed.【Result】 (1) In 2014, the average organic carbon content of different cultivated land soil types in northern Xinjiang increased by 1.61 g/kg compared with 1980, with a change rate of 4.73%. Among them, gray desert soil and brown calcium soil had the most significant increase, with a change rate of 20.27% and 15.75%. On the contrary, the organic carbon content of swamp soil lost significantly (27.74 g/kg), and the change rate reached 81.58%. (2) According to the vertical distribution of soil organic carbon content of 0-100 cm soil in northern Xinjiang arable land during the two periods, the organic carbon content of most soil types showed a trend of decreasing with the depth of the soil layer; comparison of different soil types in the same soil layer, 2014 organic carbon content of chernozem soil, chestnut soil, meadow soil, and marsh soil surface (0-20 cm) of cultivated land was lower than the average organic carbon content in 1980, and the decline was 24.57%, 6.76%, 18.15% and 121.174%. In 2014, the average organic carbon content of brown calcium soil and gray desert soil increased compared with the 1980 average by 15.95% and 16.12%. (3) There was a significant positive correlation between soil organic carbon and total nitrogen in 1980 and 2014. The correlation coefficients were R²=0.722,1 and R²=0.116,1 respectively, which were positively correlated with total phosphorus, but slightly correlated with pH. (4) In the past 40 years, the soil organic carbon content in northern Xinjiang was on the rise. Discussing the main factors influencing the change of organic carbon content, it was concluded that it is mainly affected by soil type, climatic factors, soil physical and chemical properties, fertilizer application and human activities.【Conclusion】 In the past 40 years, the soil organic carbon content of cultivated land in northern Xinjiang has generally increased, and the soil organic carbon content of different soil types is quite different. The soil organic carbon and total nitrogen are significantly correlated, which is affected by many factors.

Key words: northern Xinjiang; soil type; organic carbon content; influencing factors; soil characteristics.

摘要：

【目的】 研究新疆北疆耕地土壤有机碳含量变化特征及其影响因素分析。【方法】 收集1980年新疆第二次土壤普查和2014年土系调查数据汇总,运用方差分析、相关性分析和回归分析等方法,结合土壤全氮、全磷、pH、气候和农用化肥施肥量等影响因子,对比分析2个时期不同土壤类型有机碳含量变化的总体趋势和垂直变化特征,研究影响这种变化的自然因素和人为驱动因素。【结果】 (1)2014年新疆北疆不同耕地土壤类型有机碳平均含量总体上比1980年上升1.61 g/kg,变化率4.73%,其中上升最为显著的是灰漠土和棕钙土,变化率分别为20.27%和15.75%。沼泽土的有机碳含量损失显著(27.74 g/kg),变化率81.58%。(2)大部分土壤类型有机碳含量呈现随土层深度加深而降低的趋势;不同土壤类型同一土层相比较,2014年黑钙土、栗钙土、草甸土和沼泽土耕地表层(0 ~ 20 cm)土壤有机碳含量比1980年有机碳含量的平均值降低,降幅达24.57%、6.76%、18.15%和121.174%。而2014年棕钙土和灰漠土有机碳含量平均值则比1980年平均值增加,增幅为15.95%和16.12%。(3)1980年和2014年土壤有机碳与全氮呈显著正相关,相关系数分别为R²=0.722 1,R²=0.116 1,与全磷呈正相关,但与pH呈微弱相关。(4)近40年来新疆北疆土壤有机碳含量呈上升趋势,影响有机碳含量变化的主要因素为土壤类型、气候因子、土壤理化性质、化肥施用量及人类活动。【结论】 近40年来新疆北疆耕地土壤有机碳含量总体上升高,不同土壤类型土壤有机碳含量差异较大,土壤有机碳与全氮呈显著相关,受多因素影响。

关键词: 土壤类型, 有机碳含量, 影响因素, 变化特征