Skip to main content
ARS Home » Plains Area » Lubbock, Texas » Cropping Systems Research Laboratory » Wind Erosion and Water Conservation Research » Research » Publications at this Location » Publication #426405
Research Project: Developing Strategies for Resilient and Sustainable Crop, Water, and Soil Management in Semi-Arid Environments

Location: Wind Erosion and Water Conservation Research

Title: Biochar reduces the road-salt induced osmotic stress and improves water availability for vegetation in urban green infrastructures

Author
item FINNEGAN, MAXWELL - Temple University
item KHATEL, GANESH - Temple University
item ARCHIBALD, LUCY - University Of California Berkeley
item RINALDO, TOBIA - University Of California Berkeley
item CAPLAN, JOSHUA - Temple University
item Van Pelt, Robert
item MOHANTY, SANJAY - University Of California
item D'ORDORICO, PAOLO - University Of California Berkeley
item RAVI, SUJITH - Temple University

Submitted to: Water Resources Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/18/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary: Soil salinization has caused the fall of civilizations. Recent use of salt to melt ice and snow on paved roads has increased the threat of salinization beyond irrigated farm fields. Salt causes lowered availability of soil water for plant growth and may limit plant species that can grow in affected soils. Biochar has very large porous surfaces to adsorb ions and is being used to improve fertility of many soils. A USDA researcher along with university personnel from the University of California system and Temple University teamed to investigate whether or not biochar could reduce the negative of effects of soil salts on plant growth. We discovered that biochar did indeed reduce the negative of effects of salt on plant growth through lessening the effects salt has on water availability and recommend its use in highway and roadway melt water retention structures.

Technical Abstract: Soil salinization is an increasing global problem, especially in agricultural, coastal, and roadside environments. Although soils are often amended with biochar to remove pollutants and improve hydraulic properties, it may also mitigate the impact of salinity. Here, we compared the water retention properties and unsaturated hydraulic conductivities of both biochar-amended and unamended GSI soil media with varying salinity levels (1-25 dS m-1, using Na+ salts), The effects of salinity on both matric and osmotic potential included shifts in the plant-available water range, with the magnitude depending on the soil salt concentration and biochar content. Overall, biochar addition decreased the salinity and improved plant water availability in salt-affected. There was an increase in the integral water capacity (which describes the total amount of water the soil media can hold and release to a plant) for biochar-amended saline soils, demonstrating that biochar can reduce the total osmo-matric stress. On a macro scale, the high density of pores in biochar appears to increase soil hydraulic conductivity while reducing osmotic potential by adsorbing salt ions. On a micro scale, the negative surface charge of biochar likely counteracts the impact of the electric double layer of saline soils, reducing the total osmo-matric force on water molecules in soil solution. In effect, this helps the plant's osmotic potential to overcome the forces holding water molecules to soil grains. As soils become more saline due to ongoing climate-related snow events, biochar application might be an effective management technique for roadside and other saline soils.