Environmental Soil Chemistry Lab

Biochar for soil and environmental management

Benefits and challenges of land-application

Biochars are obtained through pyrolyzing biomass at temperatures above 300°C in the absence of oxygen. Degraded, dry lands and soils with poor fertility and low organic matter can immensely benefit from biochar amendments. In documented cases:

biochars have improved nutrient and water-holding capacities,
increased fertility and productivity, and
improved crop management efficiency.

Additional benefits come from biochar's ability to sorb contaminants, including inorganic and organic pollutants in the soil and leaching waters, thus improving soil and water quality. Using biochar as a soil amendment can help sequester stable carbon in soils and combat climate change. However, responses to biochars may depend on the type of biochar used and the specific characteristics of that biochar. Because biochar characteristics determine its suitability for specific agronomic or environmental purposes, biochar production must be tailored to address such specific needs. For more information, visit: Introduction to Biochars.

A person walking down a row of corn in a field. They are holding a container of biochar and applying it to the soil in the field.

Poultry Litter Biochar Application

Three scientists standing by a field of corn. A sign in front of them reads Phosphorus Applied 48 days after planting.

Land-application of biochar for soil and environmental management

Oral Presentations

Selected (2023-2025)

Judy JD, Renwick N, Nair VD, Lin Y, Osborne, T. (2025). Effectiveness of a suite of soil amendments to reduce P leaching from soils impacted (high-P, high-Ca) by biosolids addition in the St. Johns River basin. 14th International Symposium on Biogeochemistry of Wetlands and Aquatic Systems. Baton Rouge, Louisiana, USA. June 1-5, 2025.

Andressa Freitas. Immobilizing Phosphorus Technologies for Remediation of Biosolids Impacted Soils. 2024. ASA, CSSA, SSSA International Annual Meeting, San Antonio, TX
https://scisoc.confex.com/scisoc/2024am/meetingapp.cgi/Paper/156887

Vimala Nair. Biochar as a Nutrient Source Under Varying Soil and Climatic Conditions.
2023. ASA, CSSA, SSSA International Annual Meeting, St. Louis, MO.
https://scisoc.confex.com/scisoc/2023am/meetingapp.cgi/Paper/148655

Manuscript Publications

Freitas AM, VD Nair, T Osborne, Y Katsenovich, B Tansel, R Gudavalli, J Dickson. 2026. Review of technologies for phosphorus immobilization in biosolids-impacted soils. Science of the Total Environment, 1011, 181080.
https://doi.org/10.1016/j.scitotenv.2025.181080

Freitas AM, VD Nair, T Osborne, L Vardanyan, LR Ellis, E van Santen. 2026. Phosphorus immobilization in biosolids-impacted soils: Influence of amendment type and soil chemistry on environmental and agronomic outcomes. Journal of Environmental Management.
https://doi.org/10.1016/j.jenvman.2026.130056

Freitas AM, Nair VD, Sollenberger LE, Harris WG, and Rodriguez AN. 2025. Application and Residual Effects of Poultry Litter Biochar on Cropping System Yields. Agronomy Journal DOI: 10.1002/agj2.21745

Freitas AM, Nair VD, Harris WG, Mosquera-Losada, MA, Ferreiro-Domínguez N. 2023. Phosphorus-induced phosphorus transformations in biosolids from diverse sources. J Environ Qual. 52(1), 13–25. https://doi.org/10.1002/jeq2.20433

Nair VD, Mukherjee A. 2022. The use of biochar for reducing carbon footprints in land-use systems: Prospects and Problems. Carbon Footprints. doi: 10.20517/cf.2022.13

Freitas AM, Nair VD, Harris WG. 2020. Biochar as influenced by feedstock variability: Implications and opportunities for phosphorus management. Frontiers in Sustainable Food Systems. 4:510982 doi: 10.3389/fsufs.2020.510982

Nair VD, Nair PKR, Dari B, Freitas AM, Chatterjee N, Pinheiro FM. 2017. Biochar in the Agroecosystem–Climate-Change–Sustainability Nexus. Frontiers in Plant Science 8. 2051 doi: 10.3389/fpls.2017.02051

Dari B, VD Nair, WG Harris, PKR Nair, L Sollenberger, R Mylavarapu. 2016. Relative influence of soil- vs. biochar properties on soil phosphorus retention. Geoderma 280: 82–87. doi: 10.1016/j.geoderma.2016.06.018

Poster Presentations

2025

Poultry litter biochar (PLB) reduces P losses in sandy soils while supplying nutrients. Over 2 years with rye, corn, and sorghum on Spodosols and Ultisols, PLB yielded biomass equal to or greater than inorganic P. Its slow-release effect suggests reapplication may not be needed next cycle, supporting PLB as a sustainable P fertilizer alternative.

Biosolids recycle nutrients but can cause phosphorus (P) buildup and leaching. We tested Immobilizing Phosphorus Technologies (IPTs) and found they varied in P adsorption, shown by water-soluble P and FeO strip-P. Aluminum- and iron-based amendments best reduced P levels, though some may lower P availability enough to impact crop growth.

Related Information

Poultry Litter Biochar

Vimala Nair. 2021. Biochar as a nutrient source in agroforestry systems. Symposium. Agroforestry Research Trust. Dartington, Totnes, UK

Google Scholar- Dr. Vimala Nair