黄土高原不同地貌类型区农田土壤有机碳与其他理化属性的关系

发布时间：2018-07-09 13:10

本文选题：农田土壤有机碳 + 土壤理化性质　；参考：《西北农林科技大学学报(自然科学版)》2017年10期

【摘要】：【目的】以黄土高原不同地貌气候类型区农田土壤为研究对象,研究农田土壤有机碳与其他理化属性的关系,探讨影响有机碳的土壤因子,为区域农田土壤固碳影响因素及固碳现状评估提供理论依据。【方法】采用多专题数据图综合分析方法,考虑土地利用、种植制度、地形地貌、土壤类型等将黄土高原地区划分为5个地貌类型区,在每个地貌类型区选取一个典型县,结合"联合单元布点法"进行样点布设,运用逐步线性回归模型、回归树模型和相关性分析研究不同地貌类型区农田土壤有机碳与其他理化属性的关系。【结果】1)不同地貌类型区农田土壤有机碳与pH、砂粒含量呈显著负相关关系,与粉粒含量、全氮、全钾呈显著正相关关系,该相关性受气候和管理措施影响较小;与体积质量、黏粒含量呈负相关,与全磷、有效磷、速效钾呈正相关,该相关性受气候和管理措施影响较大。农田土壤有机碳与黏粒含量的相关关系和黏粒含量有关,当黏粒含量为20%~25%,有机碳与黏粒的相关性较高;当黏粒含量大于30%时,有机碳与黏粒呈负相关趋势。2)区域尺度上,全氮、体积质量、全磷是影响农田土壤有机碳含量的重要因子;在各个地貌类型区中,全氮是影响农田土壤有机碳含量的重要因子。关中平原区、渭北高塬区、丘陵沟壑区、银川平原区、浅山丘陵区有机碳处于最高水平时的全氮阈值分别为1.39,0.95,1.33,1.38,1.64g/kg,有机碳处于低级水平的全氮阈值分别为0.97,0.59,0.86,0.76,1.06g/kg。【结论】黄土高原不同地貌类型区农田土壤有机碳与其他理化属性的相关性存在较大差异,且受气候和管理措施影响的程度不同。整体来看,全氮是影响黄土高原全区及各县域农田土壤有机碳的重要因子。
[Abstract]:[objective] to study the relationship between soil organic carbon and other physical and chemical properties of farmland soil in different geomorphological and climatic regions of the Loess Plateau, and to explore the soil factors affecting organic carbon. This paper provides a theoretical basis for the assessment of the influencing factors of carbon sequestration and carbon sequestration in regional farmland. [methods] the comprehensive analysis method of multi-thematic data map is used to consider the land use, planting system, topography and geomorphology. The loess plateau is divided into 5 geomorphologic regions by soil type, and a typical county is selected in each geomorphologic type area. The sample is arranged by combining the "combined unit placement method", and the stepwise linear regression model is used. Regression tree model and correlation analysis study on the relationship between soil organic carbon and other physical and chemical properties in different geomorphological regions. [results] 1) soil organic carbon and pH value, sand content in different geomorphologic regions were negatively correlated. There was a significant positive correlation with the content of powder, total nitrogen and potassium, which was less affected by climate and management measures, and negatively correlated with volume mass and clay content, and positively correlated with total phosphorus, available phosphorus and available potassium. This correlation is greatly affected by climate and management measures. The correlation between soil organic carbon and clay content is related to the clay content. When the clay content is 20% and 25%, the correlation between organic carbon and clay is relatively high, and when the clay content is greater than 30%, organic carbon has a negative trend with clay (.2). Bulk mass, total phosphorus is an important factor affecting soil organic carbon content in farmland, and total nitrogen is an important factor affecting soil organic carbon content in various geomorphologic types. Guanzhong Plain, Weibei Highland, Hilly and Gully region, Yinchuan Plain, The threshold of total nitrogen at the highest level of organic carbon in the hilly area is 1.39 ~ 0.95g / kg, respectively, and the threshold of total nitrogen for organic carbon at a low level is 0.97g / kg. The threshold value of total nitrogen is 0.97g / kg. [conclusion] the soil organic carbon and other physical and chemical properties of farmland soil in different geomorphologic regions of the Loess Plateau are in the same range as those in the Loess Plateau, where the total nitrogen threshold is 0.97% 0.59% 0.86% 0.76% 0.76% + 1.06 g / kg. [conclusion] There are great differences in the correlation of sex, And affected by climate and management measures to varying degrees. Overall, total nitrogen is an important factor affecting soil organic carbon in the whole Loess Plateau and counties.
【作者单位】：西北农林科技大学林学院;西北农林科技大学水土保持研究所;中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室;
【基金】：科技基础性工作专项(2014FY210100) 中国科学院战略先导科技专项(XDA05050504) 国家自然科学基金项目(41171422)
【分类号】：S153

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