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. The cooperator reports that data were lost in a computer failure. Samples have been re-analyzed as of spring 2013, and data availability is promised by August 2013.