The hydro-microbial nexus and ecological stratification in Himalayan agroecosystems

As global agriculture faces the dual pressures of intensifying water scarcity and climate instability, optimizing Water-Use Efficiency (WUE) is essential for food security. While organic systems are recognized for their sustainability, the mechanisms governing their superior hydraulic performance remain fragmented across disciplines. This review addresses this knowledge gap by synthesizing the synergistic interactions between soil physical hydrology and microbial functions. We propose a novel hydro-microbial feedback loop as the primary driver of enhanced WUE. Our synthesis reveals that organic management fosters a living hydraulic continuum where biological engineers—specifically arbuscular mycorrhizal fungi (AMF) and biofilm-producing bacteria—actively modify soil properties. Through the production of glomalin and extracellular polymeric substances (EPS), these microbes stabilize soil aggregates, maximizing water infiltration while minimizing evaporative loss. Furthermore, we examine how microbially mediated nutrient cycling sustains plant physiological vigor under moisture stress.To contextualize these mechanisms, we integrate new metagenomic and ecological data from the Kalsi-Chakrata vertical gradient in Uttarakhand, India. This case study demonstrates a transition from human-managed chemical processing in valley basins (Vikasnagar) to sophisticated, microbially mediated survival strategies in high-altitude alpine zones (Thana), characterized by cryo-protective and stress-tolerant genomic profiles. By establishing a functional framework for soil health resilience, this paper identifies methodological limitations and proposes a future research agenda focused on hydro-microbiological modeling. Shifting perspectives toward the soil as a dynamic, biologically regulated hydraulic system is essential for advancing agricultural resilience in an increasingly uncertain climate.

Citation

Prakash, S., Verma, S., Kumari, M., Bhattacharya, N., Mehra, M., & Kumar, C. (2026). The hydro-microbial nexus and ecological stratification in Himalayan agroecosystems. Proceedings of the National Academy of Sciences, India Section B: Biological Sciences, vol(issue), pages. https://doi.org/10.1007/s40011-026-01772-6

Publisher

Springer

Journal

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences

URI

https://chesterrep.openrepository.com/handle/10034/630007

DOI

10.1007/s40011-026-01772-6

Type

Article

Language

en

Description

This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s40011-026-01772-6

ISSN

0369-8211

EISSN

2250-1746

Additional Links

https://link.springer.com/article/10.1007/s40011-026-01772-6