Kar et al. (2025) Rebuilding soil hydrological functioning by adopting conservation agriculture in the degraded lands of India’s North-West Himalayan region

Identification

• Journal: CATENA
• Year: 2025
• Date: 2025-11-21
• Authors: Saswat Kumar Kar, Ram Mandir Singh, Sridhar Patra, Raman Jeet Singh, M. Sankar, Saubhagya Kumar Samal, Gaurav Singh, R DEVARAJAN
• DOI: 10.1016/j.catena.2025.109671

Research Groups

• ICAR-IISWC, RC, Koraput, Odisha, India
• Department of Farm Engineering, I.Ag.Sc., BHU, Varanasi, Uttar Pradesh, India
• ICAR-IISWC, Dehradun, Uttarakhand, India
• ICAR-IISWC, RC, Anand, Gujarat, India

Short Summary

This study investigates the impact of land use transition from forest to various agricultural practices (conventional, reduced, and zero tillage) on soil hydraulic conductivity and dominant flow paths in the North-West Indian Himalayas. It concludes that adopting conservation agriculture can effectively restore soil hydrological functioning by diminishing infiltration-excess overland flow and enhancing subsurface flow and deep percolation.

Objective

• To assess the variations in saturated and near-saturated hydraulic conductivity of surface and subsurface soil layers and their implications on dominant flow paths under four land uses (forest, conventional tillage, reduced tillage, and zero tillage) in the North-Western Indian Himalayas.

Study Configuration

• Spatial Scale: North-Western Indian Himalayan region, comparing four land uses: forest, conventional tillage (CT), reduced tillage (RT), and zero tillage (ZT).
• Temporal Scale: Hydrological response assessed under extreme rainfall intensity (6.07 x 10⁻⁵ m s⁻¹, 50-year return period) and varying rainfall durations from 300 s to 3600 s.

Methodology and Data

• Models used: No explicit hydrological or soil models were mentioned. The study relies on direct measurement and analysis of soil hydraulic properties.
• Data sources:
  • Steady-state infiltration rate measured using a hood infiltrometer.
  • Hydraulic conductivity estimated at three pressure heads.
  • Original rainfall intensity data for Dehradun.

Main Results

• Forest land use exhibited the highest median surface hydraulic conductivity, while conventional tillage (CT) showed the lowest.
• Macropores contributed significantly to total flow, accounting for 62.0–73.4 % in the surface soil layer and 65.6–76.1 % in the subsurface layer across all land uses.
• Under extreme rainfall intensity (6.07 x 10⁻⁵ m s⁻¹, 50-year return period), all land uses experienced increased infiltration-excess overland flow (IOF) due to limited surface and subsurface conductivity.
• Forest land use maintained the highest subsurface flow (SSF, 42.5 %), the lowest IOF (38.2 %), and the greatest soil water storage.
• Conventional tillage (CT) resulted in the highest IOF (84.1 %) and the lowest SSF (4.4 %), indicating a higher risk of runoff and erosion.
• Increasing the duration of maximum rainfall intensity from 300 s to 3600 s improved subsurface flow (SSF) and deep percolation (DP) while decreasing IOF, irrespective of the return period.
• The study highlights that while converting forest to CT increased overland flow, adopting conservation agriculture practices diminished IOF and restored SSF and DP.

Contributions

• Provides quantitative evidence of the impact of land use change from forest to different agricultural tillage practices on soil hydraulic properties and dominant hydrological flow paths in the North-West Indian Himalayan region.
• Demonstrates the effectiveness of conservation agriculture in rebuilding degraded soil hydrological functioning by reducing infiltration-excess overland flow and enhancing beneficial subsurface flow and deep percolation, particularly under high rainfall intensities.
• Offers insights into the role of macropores in total flow and the hydrological response of different land management systems to extreme rainfall events in a vulnerable mountainous region.

Funding

• Not specified in the provided text.

Citation

@article{Kar2025Rebuilding,
  author = {Kar, Saswat Kumar and Singh, Ram Mandir and Patra, Sridhar and Singh, Raman Jeet and Sankar, M. and Samal, Saubhagya Kumar and Singh, Gaurav and DEVARAJAN, R},
  title = {Rebuilding soil hydrological functioning by adopting conservation agriculture in the degraded lands of India’s North-West Himalayan region},
  journal = {CATENA},
  year = {2025},
  doi = {10.1016/j.catena.2025.109671},
  url = {https://doi.org/10.1016/j.catena.2025.109671}
}