EVALUATING DIFFERENT BIOCHARS AND THEIR IMPACT ON SOIL C, TRACE GAS EXCHANGE, SOIL FERTILITY, WATER HOLDING CAPACITY AND AGROCHEMICAL FATE
Soil and Water Management Research
2013 Annual Report
1a.Objectives (from AD-416):
Evaluating different biochars and their impact on the soil system.
1b.Approach (from AD-416):
This agreement is for establishing the collaboration between Avello Bioenergy, Inc. 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, conducted at St. Paul, MN as well as other ARS locations. Avello Bioenergy 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 and other ARS locations. 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.
To date, Avello Bioenergy has supplied a limited quantity of biochar from three different feedstocks (oak hardwood, corn stover, and pine). These 3 biochars have been evaluated in long-term laboratory incubations to assess different impacts on GHG production and soil nutrient cycling. There was a significant reduction in the nitrous oxide production initially observed following biochar addition, which was universal in direction but not in magnitude for the three different biochars evaluated. However, this suppression in nitrous oxide was not statistically significant at the conclusion of the laboratory incubation. Over 90% of the biochar carbon addition was still presence in the soil sample at the conclusion of the year long incubation, which supports the notion of using biochar for carbon sequestration purposes. There was variability noted in the extracted inorganic nitrogen species at the end of the incubation. The impact of the biochar addition is related to feedstock, biochar, and soil characteristics. This project relates directly to Objective 2b of the parent research project by determining impact of feedstocks on reducing GHG emissions through biochar additions.