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Biochar Research at EPA, ORD, Pacific Ecological Systems Division
Citation:
Olszyk, D., Mark G Johnson, AND J. Novak. Biochar Research at EPA, ORD, Pacific Ecological Systems Division. Presented at Ag Issues Forum, Virtual, OR, February 25, 2021.
Impact/Purpose:
The U.S. has many areas with soil problems that would benefit from amendments. The southeastern U.S. coastal plains have degraded sandy soils with low organic matter and water retention. In the western US, there are over 33,000 abandoned sites where heavy metal contaminated mine tailings over the soil contaminate local ground and surface water sources. At the same time agricultural wastes (especially manures) and forestry wastes must be disposed of in an environmentally friendly manner. Biochar, the carbon-rich material remaining after pyrolysis (little or no oxygen) of organic waste materials has great potential as a soil amendment. Biochar can sequester fixed carbon, serve as a source, and sink for soil nutrients, improve soil uptake and water-holding capacity, serve as a repository for soil organisms, and immobilize hazardous/toxic/waste materials. EPA’s Pacific Ecological Systems Division has conducted research both on the effects of biochar on degraded soils from the southeastern U.S. and effects on biochar on superfund sites. This presentation highlights results from greenhouse studies where crops were grown in with two South Carolina soil series (Norfolk and Coxville), along with biochar produced from 6 waste feedstocks [pine chips (PC), poultry litter (PL), swine solids (SS), switchgrass (SG), and two blends of pine chips plus poultry litter (PC/PL, 50/50% and 80/20%)], which each feedstock pyrolyzed at 350, 500 and 700 ̊ C. These studies indicated that biochar could improve soil quality by increasing pH and soil nutrients, which can improve crop productivity. However, crop responses varied with crop, soil, and feedstock type. Biochar also decreased plant shoot concentrations of some key nutrient such as N and trace elements which could affect plant and human health. The presentation also described ongoing studies on the effects of a combination of lime, biosolids, and wood biochar amendments to promote establishment or plants at the Formosa superfund site in southwestern Oregon. Both studies indicated the potential for new information and techniques developed under PESD’s biochar research program to enhance establish and plant growth by improving soil chemistry, thus increasing crop productivity and the potential for success of vegetation reestablishment on degraded mine soils across the United States. Use of biochar for soil improve will also address the critical need to beneficial uses of organic waste materials.
Description:
Biochar, the carbon-rich material remaining after pyrolysis (little or no oxygen) of organic feedstocks (many of which are waste materials), has great potential as a soil amendment. Biochar can sequester fixed carbon, serve as a source, and sink for soil nutrients, improve soil uptake and water-holding capacity, serve as a repository for soil organisms, and immobilize hazardous/toxic/waste materials. The soil effects can promote plant growth. We provide highlights of biochar research at EPA’s Pacific Ecological Systems Division, focusing on effects of biochar on degraded soils from the southeastern U.S. and tailings from the Formosa Superfund site in southwestern Oregon. For the crop studies, carrot, lettuce, soybean, sweet corn were grown in a greenhouse with two South Carolina soil series (Norfolk and Coxville), along with biochar (1% by weight) produced from 6 feedstocks [pine chips (PC), poultry litter (PL), swine solids (SS), switchgrass (SG), and two blends of pine chips plus poultry litter (PC/PL, 50/50% and 80/20%)], which each feedstock pyrolyzed at 350, 500 and 700 ̊ C. Biochar (especially PL and the Norfolk soil) increased soil pH and nutrients, especially K and for the coarser Norfolk soil. Crop growth and nutrient concentration responses different with crop, soil, and biochar; but generally increased biomass and shoot K; but decreased shoot N and other elements. For mine tailing studies, a combination of lime, biosolids, and softwood biochar promoted Douglas fir establishment in the field. Thus, biochar has great potential for beneficial use of organic waste materials to promote crop growth on degraded soils, and establishment and growth of tree seedlings on mine tailings to help stabilize soils at Superfund sites.