Soil Biodiversity: The Living Dimension of Soil Health
Healthy soil is more than nutrients and moisture. It is a living system, and soil biodiversity, the community of organisms living beneath our fields, is what keeps it working. In this article, N P Singh, Senior Program Lead, Agriculture Development at S M Sehgal Foundation, explains why soil biodiversity matters for soil health and what field experience in Haryana and Punjab teaches us.
What is soil biodiversity?
The conversation around soil health tends to focus on what can be measured through its physical and chemical properties—nutrients, organic carbon, pH, and moisture. Yet a complex and living ecosystem that is fundamental to how soil functions lies beneath the surface. Microorganisms, fungi, protozoa, nematodes, earthworms, and other soil organisms interact to decompose organic matter, cycle nutrients, influence soil structure, regulate pests and diseases, and support plant growth. The Food and Agriculture Organization (FAO) recognizes soil biodiversity as fundamental to the ecosystem provided by soils, including food production, nutrient cycling, carbon sequestration, and soil moisture regulation.
Why soil biodiversity matters for soil health
Scientific evidence increasingly demonstrates that soil biodiversity is not simply a measure of what lives in the soil, but is closely connected to how effectively the soil performs its functions. A global study published in Nature Ecology & Evolution found positive associations between soil biodiversity and multiple ecosystem functions, including nutrient cycling, decomposition, and plant production. More recent synthesis has further highlighted the role of soil biodiversity in nutrient cycling, organic-matter decomposition, plant productivity, climate regulation, and pathogen control.
How farming practices affect soil life
This becomes particularly relevant in agricultural systems facing intensive cultivation, declining soil organic matter, residue burning, excessive or imbalanced use of agricultural inputs, and climate-related stresses. Agricultural practices can alter the quantity and quality of organic matter available to soil organisms and affect the habitat in which they live. FAO notes that changes in land use, tillage, fertilizer application, and the availability of plant residues also influence soil biological communities.
In other words, the way a field is managed decides how much food and shelter soil organisms have. Practices that return organic matter to the soil help sustain soil biodiversity, while practices that remove or burn it reduce the resources these organisms depend on.
From soil microbiology to contemporary agriculture
My research journey in soil microbiology began in 1996 at Govind Ballabh Pant University, Pantnagar, focusing on cellulolytic microorganisms for crop-residue decomposition in rice/wheat systems. Nearly three decades later, this foundational work remains highly relevant to sustainable soil and residue management. Crop residues are now recognized as valuable sources of carbon and nutrients rather than agricultural waste. Much research has demonstrated that residue retention, reduced tillage, and integrated management can enhance soil organic carbon and soil health. Long-term evidence from the Indo-Gangetic Plains further highlights their potential for greater carbon sequestration and reduced greenhouse-gas emissions.
Learning from the field
The S M Sehgal Foundation’s Agriculture Development program works with smallholder and marginal farmers, including women farmers, to promote sustainable agricultural practices, improve soil fertility, conserve water, and strengthen climate resilience. Through capacity building and the adoption of appropriate technologies, the program supports soil health management, efficient input use, farm mechanization, water-efficient irrigation, and sustainable crop production.
Crop residue management in Haryana and Punjab
As part of this broader approach, the SMSF teams have been working on crop residue management across Haryana and Punjab, promoting approaches that help farmers manage residues while also supporting more sustainable production systems. Our field experience includes the use of machinery such as Super Seeders as one of the approaches to in-situ residue management. A Super Seeder sows the next crop directly into the field while mixing the previous crop’s residue into the soil, so the residue is retained instead of burned.
For example, SMSF’s work across 150 villages in Kaithal and Kurukshetra districts of Haryana shows 161,100 acres covered under residue management, sequestering an estimated about 0.14 million metric tons of carbon over three years, contributing to climate-change mitigation. These experiences demonstrate the practical application of in-situ residue management at farm level.
Practices that support soil biodiversity
Based on the research and field experience shared above, farmers can support soil biodiversity through:
- Retaining crop residues in the field instead of burning them
- Using in-situ residue management machinery such as Super Seeders
- Reducing tillage where suitable
- Using fertilizers and other inputs in balanced, need-based amounts
- Following integrated soil and nutrient management to build soil organic matter
Strengthening soil health monitoring in India
India has made significant investments in soil-fertility assessment and management through initiatives such as the Soil Health Card program and the National Mission for Sustainable Agriculture. Going forward, greater attention to biological indicators and systematic monitoring of soil biodiversity, will complement existing approaches and deepen our understanding of how soils function across different agroecosystems.
Conclusion: feeding the soil that feeds the crop
Protecting soil biodiversity is ultimately about protecting the capacity of agricultural systems to renew themselves. The soil beneath a field may appear inert, but it is a living system—one whose microscopic and visible inhabitants help determine how efficiently nutrients cycle, how organic matter is transformed, how plants grow, and how resilient the agroecosystem can be. Building sustainable agriculture requires us to not only feed the crop, but also to feed and protect the soil that sustains it.
Explore more of our work on Agriculture Development and Water Management.
FAQs
Soil biodiversity is the variety of life in the soil, including microorganisms, fungi, protozoa, nematodes, and earthworms. Together, these organisms decompose organic matter, cycle nutrients, shape soil structure, regulate pests and diseases, and support plant growth.
Soil biodiversity is closely linked to how well soil performs its functions. Research shows positive links between soil biodiversity and nutrient cycling, decomposition, plant production, climate regulation, and pathogen control.
Intensive cultivation, residue burning, tillage, and excessive or imbalanced use of inputs can change the amount and quality of organic matter available to soil organisms and affect their habitat. This in turn affects soil biological communities.
In-situ crop residue management means managing crop residues within the field rather than burning or removing them. Machinery such as the Super Seeder helps farmers sow the next crop while retaining the residue in the soil.
Crop residues are a valuable source of carbon and nutrients. Residue retention, reduced tillage, and integrated management can improve soil organic carbon and soil health, increase carbon sequestration, and reduce greenhouse-gas emissions.
SMSF’s work across 150 villages in Kaithal and Kurukshetra, Haryana, covered 161,100 acres under residue management and sequestered about 0.14 million metric tons of carbon over three years.
India already assesses soil fertility through the Soil Health Card program and the National Mission for Sustainable Agriculture. Adding biological indicators and systematic monitoring of soil biodiversity would complement these efforts.
About the Reviewer
Mr. Naveen Pratap Singh
Senior Program Leader, Agriculture Development
Specialization in Soil Microbiology (G.B. Pant University of Agriculture and Technology, Pantnagar); development professional with experience in leading agriculture development initiatives in rural and remote areas. Works on promoting regenerative and natural farming approaches, introducing modern agricultural techniques, and strengthening sustainable agriculture practices. Experienced in livelihood enhancement through innovative agriculture solutions and allied activities, program development and management, and social mobilization.
Contact us 
Sign up for