Decomposition Rate Constants of Size and Density Fractions of Soil Organic Matter
Decomposition Rate Constants of Size and Density Fractions of Soil Organic Matter
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DOI：
10.2136/sssaj1995.03615995005900060018x
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发表时间：
1995-11
影响因子：
2.9
通讯作者：
J. Hassink
中科院分区：
文献类型：
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作者：
J. Hassink
描述土壤有机质周转的模型的主要缺点之一是大多数库不能通过实验确定。本研究的目的是定义可以物理分离的有意义的土壤有机质组分，并确定其分解速率常数，以便将其纳入模型。这将是验证模型的重要一步。本研究将土壤有机质分为5个组分：大有机质（> ~ 150 μm）轻组分（密度1.37 g cm -3）和粒径在20 ~ 150 μm和小于20 μm的微团聚体组分。各组分的分解速率常数依次为轻、中、重有机质（分别为23.9、9.8和3.9 x 10 -4 d -1）， C在<20 μm和20 ~ 50 μm的微团聚体组分（0.5 ~ 0.7 x 10 -4 d -1）中最低。由于组分的速率常数似乎不依赖于土壤质地，因此它们可能被广泛应用。我们建议在未来的土壤有机质模型中使用这些组分作为主要库。
One of the main drawbacks of models describing soil organic matter turnover is that most pools cannot be experimentally identified. The aim of this study was to define meaningful soil organic matter fractions that can be physically isolated and to determine their decomposition rate constants so that they can be incorporated into models. This would be a major step toward verification of models. In this study, soil organic matter was separated into five fractions : the light (density 1.37 g cm -3 ) fractions of macroorganic matter (>150 μm) and the microaggregate fractions with particle sizes between 20 and 150 μm and smaller than 20 μm. The decomposition rate constants of the fractions decreased in the order light, intermediate, and heavy macroorganic matter (23.9, 9.8, and 3.9 x 10 -4 d -1 , respectively) and were lowest for C in the microaggregate fractions <20 and 20 to 50 μm (0.5-0.7 x 10 -4 d -1 ). Since the rate constants of the fractions seemed not to depend on soil texture, they can probably be applied widely. We propose to use these fractions as the principal pools in future soil organic matter models.