Beneath every Indian farm field lies an unseen workforce of earthworms, springtails, mites, ants, fungi and bacteria that quietly recycles nutrients, builds soil structure and sustains crop productivity. A new systematic review published in Discover Soil has, for the first time, stitched together more than five decades of Indian soil biodiversity research into a single national picture, and the results reveal both remarkable hotspots of subterranean life and alarming blind spots in the scientific record. Led by Manendra Singh of the WOTR Centre for Resilience Studies in Pune, the team synthesised 41 peer-reviewed studies published between 1970 and 2025, using the ROSES protocol for systematic evidence syntheses to ensure that only studies meeting strict reporting standards entered the analysis.
The scale of the compiled dataset is striking. Across ten states and two union territories, the synthesis documented 205 soil faunal species and orders, distributed across three broad groups defined by the Food and Agriculture Organisation’s classification framework. Microfauna, including bacteria, fungi and protozoa, accounted for 47 recorded taxa, mesofauna such as mites, springtails and enchytraeids contributed 56, and macrofauna, encompassing earthworms, ants, termites and beetles, dominated with 102 species or orders. These organisms were recorded across 11 agricultural and tree-based land uses, spanning rice fields, organic farms, shifting cultivation, fallows, and plantations of teak, bamboo, acacia, cassia, mango and sal.
Geographically, the picture is deeply uneven. Karnataka emerged as the species-richest state with 53 recorded taxa, followed closely by Meghalaya with 49 and Tripura with 28, while Uttar Pradesh yielded only two species in the compiled literature. When the researchers calculated the Shannon-Wiener diversity index, a standard ecological metric that combines species richness with the evenness of their abundances, values ranged from a low of 0.3 in Uttar Pradesh to a high of 3.8 in Meghalaya. Intermediate values between 1.5 and 2.0 characterised Tripura, Orissa and Rajasthan, while Maharashtra, West Bengal, Tamil Nadu, and the union territory of Leh and Ladakh fell between 2 and 3. Meghalaya also recorded the highest number of mesofauna species, whereas Karnataka led in microfauna with 40 species.
The relationship between soil type and soil life proved equally revealing. Tripura and Tamil Nadu stood out with 20 soil faunal groups recorded across six soil types or orders, indicating diverse pedo-environmental conditions that support a wide range of below-ground communities. By contrast, the synthesis detected a weaker association between faunal diversity and soil type in Leh and Ladakh, Meghalaya and Rajasthan, a pattern the authors attribute to variation in pedo-climatic conditions. Across the national dataset, Inceptisols and sandy loam soils consistently supported the greatest diversity of ants, earthworms and microarthropods, particularly the springtails of the order Collembola and the mites of the group Cryptostigmata. The recurrence of earthworm genera such as Metaphire, Drawida and Perionyx across different soil types points to their broad ecological adaptation.
Land management emerged as a decisive filter on which organisms thrive. Croplands under conventional farming, with high inputs of inorganic fertilisers and pesticides, supported lower soil faunal diversity and abundance than ecologically managed systems. Microfauna and macrofauna, including earthworms, mites and springtails, were consistently present in organic and integrated farming systems, while conventional and integrated farms shared similar communities dominated by resilient taxa. Tree-based systems told their own story: the phylum Arthropoda was abundant in bamboo and teak plantations, suggesting favourable microclimatic conditions for detritivores and predators, and arthropod dominance was greater in the structured, litter-rich habitats under acacia, cassia, mango and sal than in agriculture, fallows or shifting cultivation. Actinomycetes appeared only under acacia plantations, possibly reflecting associations with litter or humus-rich soil, while millipedes and molluscs were found exclusively in mixed plantations.
To formalise these patterns, the team applied principal component analysis and Pearson correlation statistics in R. The PCA showed that the first two components together explained roughly half of the variability in faunal occurrence across agroecosystems, with PC1 accounting for 28 percent and PC2 for 22.2 percent. Most agroecosystems, including organic farming, shifting cultivation, acacia plantations and conventional agriculture, clustered together, indicating broadly similar soil faunal composition. But two systems stood apart: mixed plantations and mango orchards harboured unique, divergent communities. The mango orchard was particularly distant along PC1, its separation driven by ants, beetles, spiders, snails, centipedes and caterpillars, which correlated strongly and positively with that land use. In the correlation matrix, isolates and mesofauna showed an almost perfect positive relationship at r = 0.98, while species richness was negatively correlated with both mesofauna, at r = -0.17, and isolates, at r = -0.28, a counterintuitive result that underscores how little is still understood about the drivers structuring these communities.
The review places these findings against a sobering national backdrop. Soil degradation affects nearly 121 million hectares, roughly 40 percent of India’s land, and the average soil organic carbon content of Indian soils is about 0.54 percent, well below critical thresholds for biological function. Excessive inorganic fertiliser use induces acidification and disrupts the relationship between above-ground and below-ground biodiversity. The authors note that the diversity and abundance of soil organisms decline as soil organic carbon falls, reducing metabolic interactions, and they argue that India’s soil organic carbon management programmes and policies need reform. National schemes such as the National Mission for Sustainable Agriculture and the Soil Health Card programme currently focus on chemical fertility, leaving the biological dimension of soil health largely unmeasured at the national scale.
Climate change adds a further layer of urgency. The review highlights that rising temperatures accelerate microbial metabolism but can reduce diversity by favouring heat-tolerant species, while precipitation anomalies, producing droughts and floods, negatively affect microbial and faunal communities through shifts in soil moisture regimes. The higher diversity observed in Meghalaya and Karnataka suggests that moisture availability is critical for sustaining soil biota. The authors argue that the crop-climate-soil-biodiversity nexus must be understood across India’s diverse cropping systems and integrated with projected climatic scenarios, particularly since extreme weather events disproportionately harm sensitive or endemic taxa. They also flag a methodological gap: most Indian studies rely on a single sampling event, which limits any understanding of temporal change, and functional roles of soil organisms, assessed with tools such as metagenomics and meta-transcriptomics, remain scanty.
The path forward, the researchers conclude, lies in aligning Indian soil biodiversity science with international frameworks. They recommend adopting the standardised sampling protocols of the Global Soil Biodiversity Atlas and the Global Soil Biodiversity Initiative, deploying DNA metabarcoding for accurate estimates of microbial and faunal diversity, and developing agro-ecological zone-wise predictive models to anticipate the impacts of land-use change. They also call for research into soil microbial genomics, micro-food webs and the ecosystem services delivered by soil biota, arguing that soil biodiversity should be treated as a primary component of nature-based solutions for sustainable agriculture. With India’s 20 agro-ecological zones and 15 climatic zones harbouring an extraordinary but poorly documented wealth of underground life, the review makes clear that the country’s next agricultural revolution may depend less on what is planted above ground than on what is protected below it.
Subject of Research: Soil biodiversity research across Indian agroecosystems
Article Title: Mapping the progress of soil biodiversity studies in India to address research gaps and opportunities
Article References: Singh, M., Purohit, S., Wadhu, A. M., Hande, O. M., Khan, Y. D. I., & Gholkar, M. D. (2026). Mapping the progress of soil biodiversity studies in India to address research gaps and opportunities. Discover Soil, 3(1), Article 111. https://doi.org/10.1007/s44378-026-00260-7
Image Credits: AI Generated
DOI: 10.1007/s44378-026-00260-7
Keywords: soil biodiversity, India, agroecosystems, soil fauna, earthworms, microarthropods, Shannon-Wiener index, soil organic carbon, agroforestry, climate change, DNA metabarcoding, sustainable agriculture
News Source: Alan Morgan. (October 5, 2026). India’s Hidden Soil Life Mapped: Five Decades of Data Reveal Gaps Beneath Our Feet. Scienmag.
