Abstract

The distribution of total organic matter (C_org), particulate organic matter (C_POM), and potentially mineralizable organic matter (C₀) in mega- (10–5 and 5–2 mm), macro- (2–0.25 mm), and microaggregates (<0.25 mm) isolated by dry sieving from gray and agrogray soils (Luvic Retic Greyzemic Phaeozems) of different land uses was studied. In the soils under forest and meadow, the highest C_org content was detected in the megaaggregates of 5–2 mm in size (43 and 37% of C_org in whole soil sample, respectively), whereas in the arable soil, it was found in macroaggregates (45%). In the uncultivated soil, the C_POM was mainly accumulated in megaaggregates (65–72% of the C_POM in the whole sample); in the arable soil, it was equally distributed between mega- and macroaggregates (46–45%). The fine (0.25–0.05 mm) C_POM subfraction in the uncultivated and arable soils contained 1.3- and 2.3-fold more carbon, respectively, as compared with the coarse (2–0.25 mm) C_POM subfraction. The C₀ content in the aggregates correlated with C_POM and C_org. Decomposition of plant residues with a wide C : N ratio in soil increased with a decrease in the aggregate size. However, aggregate size did not influence the decomposition of plant residues with a narrow C : N ratio. The effect of aggregate size on the decomposition rate mainly appeared at the early stages of transformation of plant residues.

中文翻译：

---

团聚体大小，颗粒有机物含量与土壤中植物残体分解之间的关系

摘要

总有机物（C _org），颗粒有机物（C _POM）和潜在可矿化的有机物（C ₀）的分布范围为mega-（10-5和5-2 mm），macro-（2-0.25 mm） ，并研究了通过干筛分离出不同土地利用的灰色和农业土壤（Luvic Retic Greyzemic Phaeozems）中的微骨料（<0.25 mm）。在森林和草甸下的土壤中，最大的C _org含量在5–2 mm的大型聚集体中被检测到（分别为整个土壤样品中C _org的43％和37％），而在耕地中发现了C _org在大型集合中（45％）。在未耕种的土壤中，C _POM主要积累在巨型聚集体中（占C _POM的65–72％在整个样本中）；在耕作土壤中，它平均分布在大型集料和大型集料之间（46-45％）。细（0.25-0.05毫米）C _POM在未开垦和耕地土壤亚含有1.3倍和分别作为与粗（2-0.25毫米）C相比2.3倍的碳_POM亚。骨料中的C ₀含量与C _POM和C _org相关。土壤中碳氮比高的植物残渣的分解随着团聚体尺寸的减小而增加。但是，骨料的大小并不影响C：N较窄的植物残渣的分解。聚集体大小对分解速率的影响主要出现在植物残体转化的早期。