Fate of particulate organic matter in soil aggregates during cultivation
Fate of particulate organic matter in soil aggregates during cultivation
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DOI：
10.1111/j.1365-2389.1996.tb01849.x
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发表时间：
1996-12-01
影响因子：
4.2
通讯作者：
Arrouays, D
中科院分区：
文献类型：
--
作者：
Besnard, E;Chenu, C;Arrouays, D
颗粒有机质(POM)是土壤有机质中一种不稳定的部分，被认为是在土壤团聚体中被物理保护而不被生物降解的部分。我们开发了一种分级方法，将位于稳定土壤大团聚体(200亩)和微团聚体(50-200亩)外的POM与其内部的POM分离，并将其应用于腐殖质壤土的栽培序列。C-13的自然丰度被用来确定来自森林的POM和来自作物的POM在游离态和闭锁态中的数量。在森林土壤中，游离和封闭的POM组分具有相同的组成、形态和同位素特征。在培养过程中，POM的数量急剧下降。森林POM中碳的流失主要来自团聚体外的POM。包埋在微团聚体中的POM周转缓慢。这可能是由于其顽固的化学性质或其在微聚集体中的物理保护。
Particulate organic matter (POM) is a labile fraction of soil organic matter which is thought to be physically protected from biodegradation when within soil aggregates. We have developed a fractionation method to separate POM located outside stable soil macroaggregates (>200 mu m) and microaggregates (50-200 mu m) from that within them, and applied it to a cultivation sequence of humic loamy soils. The natural abundance of C-13 was used to determine the amounts of POM derived from forest and that derived from crop in the free and occluded fractions. In the forest soil the free and occluded POM fractions had the same composition, morphology and isotopic signature. On cultivation the amounts of POM decreased sharply. The loss of C in the POM from forest was mainly from POM outside the aggregates. The POM occluded within microaggregates was found to turnover slowly. This may be due either to its recalcitrant chemical nature or to its physical protection within microaggregates.