Impact of biochar on agricultural nitrogen management
2021
- Biological Systems Engineering UW Madison
- Soil and Crop Science, UW Platteville
Project Media
Biochar is a carbon rich product resulting from the pyrolysis of organic materials. Biochar produced
through this process is generally used as a soil amendment or incorporated into other agricultural nitrogen
management systems and is thought to reduce nitrogen leaching and improve available nitrogen for crop
production. However, biochar characteristics vary significantly based on the feedstock and production
characteristics. The varying production characteristics and feedstocks can significantly alter the surface
chemistry which leads to varying impacts when integrated into the soil or other agricultural nitrogen
management systems. When biochar was applied to soil systems in agricultural filter strips, it was able to
significantly reduce cumulative nitrate leaching by 40% in a field trial (Sanford and Larson, 2020a). Most
of this nitrate leaching reduction was attributed to the retention of nitrogen within the soil matrix. When
biochar soil amendments were further investigated in laboratory soil column studies, nitrate reductions
were attributed primarily to retention of organic nitrogen and nitrate within the soil (Sanford and Larson,
2020b). In addition, the integration of biochar within these soils resulted in reductions of nitrous oxide
emissions, a potent greenhouse gas. Biochar has potential to reduce losses of nitrogen to the environment
and retain this nitrogen within the soil matrix for crop needs.