EVALUATING DIFFERENT BIOCHARS AND THEIR IMPACT ON SOIL C, TRACE GAS EXCHANGE, AND AGROCHEMICAL FATE AND TRANSPORT
Soil and Water Management Research
2013 Annual Report
1a.Objectives (from AD-416):
Evaluating different biochars and their impact on soil C, trace gas exchange and
agrochemical fate and transport.
1b.Approach (from AD-416):
This agreement is for establishing the collaboration between Best Energies and USDA-ARS to allow different feedstock and operating conditions on a pyrolysis plant to be evaluated on the impacts of the resulting biochar for soil amendments. This will entail a combination of field and laboratory research on the impact of various biochars on soil microbial processes, agrochemical transport and trace gas exchange. Best Energies will provide the production data on the biochar along with the biochar itself for the research. Laboratory incubations will assess the immediate impacts and field scale plot research would be conducted to evaluate the long-term (>3 years) effects in a continuous corn rotation in Minnesota. The main goal of the research is to examine if the combination of altering feed stocks or production parameters can result in a biochar that is more beneficial from a C sequestration perspective as well as an agent for reducing greenhouse gas emissions and agrochemical losses from the agricultural soil system.
This project has been completed.
1. Best Energies did supply sufficient biochar from a slow pyrolysis process from their plant in Australia to apply to triplicate field plots (16’ x 16’) in Rosemount, MN. These field plots evaluated the impacts of the biochar addition on a continuous no-till corn production in the Upper Midwest. The biochar was applied in the fall of 2009 and was incorporated by rotary tillage (rototiller). There were no increases in corn yield observed during any year of the project. There were increases in soil C contents from the biochar addition that persisted for the 3 years of the study.
2. There were initial decreases observed in the soil nitrous oxide production following biochar additions in laboratory incubations, but this suppression in N2O production was not observed in the field plots.
3. There were differences noted in the impact of fresh and weathered biochar additions on soil nitrous oxide production rates. Weathered biochar increased the net soil nitrous oxide production and fresh biochar decreased the observed soil N2O production. These results suggest the transient nature of biochar’s impact on greenhouse gas emissions cannot be accurately predicted based on the initial observations. This project relates directly to Objective 1a of the Farming Practices for the Northern Corn Belt to Protect Soil Resources, Support Biofuel Production and Reduce Global Warming Potential research project by determining farming practices that have the potential of reducing GHG emissions at the plot level through biochar additions.