Extractable lipid contents and colour in particle‐size separates and bulk arable soils
Extractable lipid contents and colour in particle‐size separates and bulk arable soils
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粒径分离物和散装耕地土壤中的可提取脂质含量和颜色
DOI：
10.1111/j.1365-2389.2005.00754.x
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发表时间：
2006
影响因子：
4.2
通讯作者：
Michael W. I. Schmidt
中科院分区：
文献类型：
--
作者：
G. Wiesenberg;L. Schwark;Michael W. I. Schmidt
植物生物量对土壤有机质的化学改变往往伴随着特征趋势，例如，随着颗粒尺寸的减小和深度的增加，有机碳和氮浓度以及稳定碳同位素值（δ 13 C）往往增加。在农业土壤中，系统研究土壤有机碳（SOC）分布在非整土和深度剖面颗粒分离很少。在这项研究中，三个土壤剖面从一个网站与不同的单一作物进行了分析，有机碳和氮浓度，稳定碳同位素，散装可提取的脂质，和土壤颜色。与大多数以前的观测结果相反，稳定的碳同位素值在土壤深度和粒度分离范围内是恒定的，这可能是由于所采用的收获技术和化石碳的存在导致生物量输入很少的结果。大量可提取的脂质占总SOC的1-10%。从黑麦中提取的脂质明显多于玉米来源的SOC。标准化为土壤质量的脂质产量随粒径减小而增加，随深度减小而减少。当归一化为有机碳浓度时，砂粒级分具有最大的脂质产量。土壤颜色，表示为孟塞尔值，是最轻的砂和粉砂大小分离。孟塞尔值及其SOC浓度的交叉图显示了每个粒度级别和散装土壤的特征性非重叠区域。粘土粒度分离物和松散土壤的孟塞尔值几乎相同，尽管粘土粒度分离物的SOC浓度远大于松散土壤。因此，SOC-丰富的粘土-大小分离施加的主要影响的颜色的散装土壤。颜色和可提取的脂质含量的测定可能是有用的土壤特性的附加参数。
Chemical alteration of plant biomass to soil organic matter is often accompanied by characteristic trends, e.g. with decreasing particle size and increasing depth organic carbon and nitrogen concentrations and stable carbon isotope values (δ13C) often increase. In agricultural soils, systematic studies of soil organic carbon (SOC) distribution in bulk soils and particle‐size separates of depth profiles are scarce. In this study, three soil profiles from one site with different monoculture crops were analysed for organic carbon and nitrogen concentrations, stable carbon isotopes, bulk extractable lipids, and soil colour. In contrast to most previous observations, stable carbon isotope values were constant over soil depth and within particle‐size separates, probably as a result of little biomass input due to the harvesting techniques applied and the presence of fossil carbon. Bulk extractable lipids contributed 1–10% to the total SOC. Significantly more lipids could be extracted from rye‐ than from maize‐derived SOC. Lipid yields normalized to soil mass increased with decreasing particle size and decreased with depth. When normalized to organic carbon concentration, sand‐size fractions had the largest lipid yields. Soil colour, expressed as Munsell values, was lightest in sand‐ and silt‐size separates. A cross‐plot of Munsell values and their SOC concentrations revealed characteristic, non‐overlapping areas for each particle‐size class and the bulk soils. Clay‐size separates and bulk soils were almost identical in Munsell values, although for clay‐size separates SOC concentrations were much larger than for bulk soils. Thus, the SOC‐rich clay‐size separates exerted the dominant influence on the colour of the bulk soils. Determination of colour and extractable lipid contents could be useful additional parameters for soil characterization.