Improving nutrient retention with biochar

Project Overview

Project Type: Graduate Student
Funds awarded in 2010: $9,852.00
Projected End Date: 12/31/2012
Grant Recipient: University of Florida
Region: Southern
State: Florida
Graduate Student:
Major Professor:
Dr. Danielle Treadwell
University of Florida

Annual Reports


  • Vegetables: greens (lettuces)


  • Crop Production: municipal wastes, nutrient cycling, organic fertilizers
  • Education and Training: extension
  • Energy: bioenergy and biofuels
  • Natural Resources/Environment: carbon sequestration
  • Production Systems: organic agriculture
  • Soil Management: earthworms, nutrient mineralization, organic matter, soil analysis, soil quality/health

    Proposal abstract:

    Biochar is the carbon-rich by-product obtained when biomass is heated in a closed container with limited oxygen. Biochar has become a subject of increasing scientific interest due to its potential to sequester large quantities of carbon (thereby mitigating global climate change) and its potential to improve agronomic systems, including: increased fertilizer retention, increased cation-exchange capacity, increased pH of acidic soils, increased water retention, increased soil microbial capacity, and other benefits. Several methods have been developed for producing biochars including slow and fast pyrolysis, flash pyrolysis, gasification, and hydrothermal carbonization. The product produced from hydrothermal carbonization has superior potential for adoption in horticultural systems, because the process itself mimics the natural formation of peat. Hydrothermal carbonization involves the use of moderate temperatures and pressures over an aqueous solution of biomass in a dilute acid for several hours. The process is also advantageous because it gives off more energy than it consumes (exothermic); and, unlike other methods, it is a wet process, allowing higher moisture biomass to be efficiently carbonized. Because of the rapid growth of the biochar industry and increased scientific interest, an opportunity exists to determine appropriate management strategies for on-farm implementation of biochar, for optimizing biochar performance, and for understanding biochar’s effects on soil fertility and sustainable crop production. We propose to investigate the effect of biochar produced through the process of hydrothermal carbonization, applied with and without common soil amendments (manures, fertilizers, and composts) on soil biological, physical, and chemical properties in the greenhouse.

    Project objectives from proposal:

    The goal of this project is to increase nutrient retention, crop productivity, and soil quality by adding biochar in various management contexts, and to compare various application rates and biochar-compost, biochar-manure, and biochar-fertilizer combinations. The objectives are to:

    1. Evaluate biochar + “amendment” combinations in a greenhouse setting in regards to nutrient retention, nutrient availability, soil moisture retention and crop productivity. Establish the precise parameters for future field trials, in regards to biochar application rate and amendment quantities.

    2. Prepare and deliver outreach to inform growers, the public, and scientific audiences of results of research.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.