1a. Objectives (from AD-416):
Measure soil microbial activity and soil carbon fractions of pretreatment soils collected from the Long Term Biomass Experiment at Temple, TX.
1b. Approach (from AD-416):
GSWRL will collect soils from 24 experimental plots. Soil samples consist of soils from 0-3, 3-6, 6-12, 12-24, and 24-36" depth increments from three pooled 1.5" diameter cores per plot. Coarse (>250 micrometer) and fine (250-53 micrometer) particulate organic matter will be assessed on these samples using established procedures. Active soil microbial biomass will be determined using a substrate-induced respiration technique, and long-term (1-year) laboratory incubations will be conducted on two subsamples from each plot. These 1-year incubations will be used to determine soil pool sizes and turnover using a two-pool model of soil organic matter decomposition.
3. Progress Report:
The cooperator is assessing carbon pools in soils collected at the beginning of the Long Term Biomass Experiment. These data will provide a crucial baseline against which to assess potential changes in soil carbon pools resulting from the experimental treatments. The agreement funds lab supplies and a student assistant. All soil samples have been fractionated and analyzed for carbon and nitrogen contents, and the cooperator is currently summarizing these results for presentation at the 2012 National Institute of Food and Agriculture (NIFA) Principal Investigator meeting.