ARS | Publication request: Impact of designer biochars on soil physical characteristics

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 3, 2010
Publication Date: N/A

Technical Abstract: Biochar quality can improve soil fertility; however, little information is known about its effects on physical characteristics. By manipulating biochar pyrolytic conditions and feedstock selection, we hypothesized that designer biochars can be created to improve distinct soil physical characteristic (i.e., water holding capacity, soil strength). Biochars were designed with slow and fast pyrolysis using peanut hulls, poultry litter, pecan shells, hardwoods and switchgrass at temperatures ranging from 250 to 700ºC. They were mixed at 0 and 2% (by weight) into pots containing a sandy Ultisol from South Carolina and two silty Aridisols from Washington and Idaho. Mixes were laboratory incubated at 10 or 15% soil moisture content (by weight) for up to 120 days. Treatments were leached four times over the experiment with 1.2 pore volumes of deionized water. To help determine water holding capacities, gravimetric soil moisture contents were tracked daily after each leaching event. To determine soil strength, penetration resistances were measured at the soil surface using a probe connected to a strain gauge. Some biochars increased soils water holding capacity relative to the controls and decreased penetration resistance suggesting that biochar quality can affect selected soil physical characteristics.