Soil Organic Matter Dynamics and Soil Health: A Critical Synthesis of Formation, Persistence, Function and Management
Shiv Raj Dager *
Department of Agricultural Chemistry and Soil Science, C.P. College of Agriculture, Sardarkrushinagr Dantiwada Agricultural University, Gujarat, India.
Prasanna B. Khaire
Soil and Water Conservation Engineering, Mahatma Phule Krishi Vidyapeeth, Rahuri, Maharashtra, India.
Wajid Meerak
Krishi Vigyan Kendra, Kupwara, SKUAS, Jammu and Kashmir-193224, India.
Tarun Kumar
Department of Soil Science and Agricultural Chemistry, College of Agriculture, Sadar Vallabbhai Patel University of Agriculture and Technology, Meerut - 250110, Uttar Pradesh, India.
Vivek Tiwari
Department of Agronomy, Chaudhary Sarwan Kumar Himachal Pradesh krishi Vishwavidyalaya, Palampur, Himachal Pradesh, India.
Beerendra Singh
Bihar Agricultural University, Horticulture Research Centre, Kishanganj- 855107 (Bihar), India.
Vangala Siva Nagi Reddy
Department of Agronomy, College of Agriculture, Annamacharaya University, Rajampet, Kadapa, Andhra Pradesh, India.
Battala Sheshagiri
Department of Agricultural Economics, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj – 211007, Uttar Pradesh, India.
*Author to whom correspondence should be addressed.
Abstract
Soil organic matter (SOM) is central to soil functioning, yet its significance cannot be inferred reliably from bulk carbon concentration alone. The processes that generate, transform, redistribute and protect organic compounds operate across interacting biological, mineralogical, hydrological and management gradients. This critical narrative review evaluates how contemporary understanding of particulate organic matter, mineral-associated organic matter and microbial transformation changes interpretations of soil health and agricultural carbon management. Peer-reviewed experimental studies, long-term field investigations, meta-analyses and conceptual papers were selected through topic-specific scholarly searching and citation tracing, with particular attention to contrasting results and measurement limitations. Evidence supports substantial roles for organic matter in aggregation, nutrient cycling, biological habitat and, in particular settings, hydrological regulation. The magnitude and direction of these functions nevertheless depend on soil texture, mineralogy, climate, depth and the composition and spatial distribution of carbon pools. Microbial-derived material contributes importantly to mineral-associated organic matter, but mineral association is neither a guarantee of permanence nor a direct measure of biological usefulness. Meta-analyses indicate that cover crops and organic amendments can increase soil carbon, while benefits differ among fractions, soil layers and management histories. The assumption that no-tillage necessarily sequesters carbon is weakened when whole-profile stocks and equivalent soil mass are considered. Likewise, observed carbon–yield and carbon–water relationships should not be interpreted as invariant causal responses. The review argues for a function-oriented framework that assesses organic carbon stocks alongside accessibility, turnover, aggregation, nutrient supply and context-specific biological indicators. Its priorities include long-term depth-resolved experiments, transparent fractionation, source tracing, whole-system greenhouse-gas accounting and locally calibrated soil-health benchmarks. SOM management is most defensible when it seeks multiple measurable soil functions rather than treating a single carbon indicator as a universal proxy for resilience or climate benefit.
Keywords: Particulate organic matter, mineral-associated organic carbon, microbial necromass, soil aggregation, carbon sequestration, rhizosphere processes, soil quality assessment, sustainable land management