Abstract

Soil microbial respiration is a biological process that converts soil organic matter into atmospheric CO₂ via soil microorganisms. It reflects the overall metabolic activity of soil microbial populations and usually used as an indicator of soil health. Soil chemical properties, among others, have an influence on a catabolic capacity of the soil and greatly vary among different soil layers. In this study, we examined patterns of chemical soil properties and soil microbial respiration along 0–10 and 10–25 cm depths of the soil to investigate if soil depth had any effects on soil chemical properties and how these changes with depth could shift the soil microbial respiration. We employed basal respiration method to estimate the rate of soil microbial respiration and measured important chemical properties using standard protocols. The results showed differential effects of soil depth on chemical properties where available nitrogen (\({\text{NH}}_{{\text{4}}}^{{\text{ + }}}\)–N, \({\text{NO}}_{3}^{ - }\)–N, and total N), cation exchange capacity, and Mg²⁺ were strongly influenced by soil depth. Soil microbial respiration greatly differed among the two soil depths (p = 0.0005) with a higher rate of soil microbial respiration in surface soils compared to subsurface soils. Soil microbial respiration had a significant positive correlation with total N, \({\text{NO}}_{3}^{ - }\)–N, \({\text{NH}}_{{\text{4}}}^{{\text{ + }}}\)–N, and soil organic matter (r = 0.98, 0.974, 0.9625, and 0.9455, respectively). The variation of soil microbial respiration was closely linked with the variation of soil organic matter and available nitrogen, implying that these variables were the key drivers of the variation of soil microbial respiration in the study area. Overall, the study highlighted that soil quality assessments and managements should include the depth effects to provide a better understanding of the dynamics of microbial respiration in the soil.

中文翻译：

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深度对上部土壤层中土壤化学性质和微生物呼吸的影响

摘要

土壤微生物呼吸是将土壤有机质转化为大气CO ₂的生物过程。通过土壤微生物。它反映了土壤微生物种群的整体代谢活动，通常用作土壤健康的指标。除其他外，土壤化学性质对土壤的分解代谢能力有影响，并且在不同的土壤层之间差异很大。在这项研究中，我们研究了化学土壤性质和土壤微生物沿0–10和10–25 cm深度的分布模式，以调查土壤深度是否对土壤化学性质有任何影响，以及这些变化随深度的变化如何改变土壤微生物呼吸。我们采用基础呼吸法来估算土壤微生物呼吸的速率，并使用标准方案测量重要的化学性质。结果表明在可用氮（\（{\ text {NH}} _ {{\ text {4}}} ^ {{\ text {+}}} \）– N，\（{\ text {NO}} _ {3} ^ {- } \）– N和总N），阳离子交换量和Mg ²⁺受到土壤深度的强烈影响。两种土壤深度之间的土壤微生物呼吸差异很大（p = 0.0005），表层土壤的微生物呼吸速率高于地下土壤。土壤微生物呼吸与总氮（\（{\ text {NO}} _ {3} ^ {-} \）– N，\（{\ text {NH}} _ {{\ text {4 }}} ^ {{{\ text {+}}} \）– N和土壤有机质（r =分别为0.98、0.974、0.9625和0.9455）。土壤微生物呼吸变化与土壤有机质和速效氮变化密切相关，表明这些变量是研究区域土壤微生物呼吸变化的关键驱动力。总体而言，研究强调土壤质量评估和管理应包括深度影响，以更好地了解土壤中微生物的呼吸动力学。