Rock Fragments Control Size and Saturation of Organic Carbon Pools in Agricultural Topsoil
Rock Fragments Control Size and Saturation of Organic Carbon Pools in Agricultural Topsoil
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DOI：
10.2136/sssaj2010.0454
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发表时间：
2011-09
影响因子：
2.9
通讯作者：
Ludger Bornemann;M. Herbst;G. Welp;H. Vereecken;W. Amelung
中科院分区：
文献类型：
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作者：
Ludger Bornemann;M. Herbst;G. Welp;H. Vereecken;W. Amelung
岩石碎片（RF）可能会严重减少单位土壤体积的细土（FE）量。在这里，我们量化的影响变量RF散装土壤有机碳（SOC），颗粒有机质（POM）的三个大小类，非颗粒有机质（nonPOM），和黑碳（BC）的空间格局。在Selhausen（德国）附近的一块耕地上，在规则网格中采集了129个土壤样本（0-30 cm）。弱倾斜场地的RF梯度很大，土壤类型包括Alfic Eutrochepts，以及Typic和Albaquic Hapludalfs。除了C-池模式和RF，我们确定了质地，铁氧化物，土壤水分，以及山坡和海拔高度。此外，还进行了137 Cs测量，以指示土壤侵蚀。减少SOC股票的增加量的RF在百分比的基础上是小于归因于单纯的稀释效应。多元回归分析表明，RF和FE含量的BC，nonPOM，和最好的POM馏分之间的BETA值为0.65至0.73。POM粗粒级C含量与RF含量呈正相关（R2 = 0.72-0.78），其空间分布格局可能是由于RF含量增加时，植物凋落物的不均衡输入造成的。统计结构分析和变差分析指出，分层C饱和的nonPOM和最好的POM馏分，这是另外调节氧化铁含量。只有碳的空间分布（BETA =-0.15）受侵蚀的影响。
Rock fragments (RF) may severely reduce the amount of fine earth (FE) per soil volume. Here we quantified the effect of variable RF on spatial patterns of bulk soil organic carbon (SOC), particulate organic matter (POM) of three size classes, nonparticulate organic matter (nonPOM), and black carbon (BC). One hundred and twenty-nine soil samples (0-30 cm) were taken in a regular grid on an arable field nearby Selhausen (Germany). The weakly inclined site featured a strong gradient in RF, soil types covered Alfic Eutrochepts, as well as Typic and Albaquic Hapludalfs. In addition to C-pool patterns and RF we determined texture, Fe oxides, soil moisture, as well as hillslope and elevation above sea level. Additionally, 137 Cs measurements were conducted to indicate soil erosion. The reduction of SOC stocks by increasing amounts of RF on a percentage basis was smaller than attributable to mere dilution effects. Multiple regression analysis indicated BETA values of 0.65 to 0.73 between RF and FE contents of BC, nonPOM, and the finest POM fraction. The C contents of the coarse POM fractions were positively correlated with the amount of RF (R 2 = 0.72-0.78) and their spatial patterns were assumed to be caused by disproportionate input of plant litter to a reduced solum when the amount of RF increased. Statistical structure analysis and variography pointed to hierarchical C saturation of nonPOM and the finest POM fraction, which was additionally regulated by Fe oxide contents. Only the spatial distribution of BC (BETA = ―0.15) was affected by erosion.