Submitted to: Soil Ecology Society Conference
Publication Type: Abstract Only
Publication Acceptance Date: 5/20/2001
Publication Date: 5/20/2001
Citation: Kisselle, K.W., Franzluebbers, A.J., Molina, M., Burke, R.A., Stuedemann, J.A. 2001. Effects of nutrient inputs and forage (cattle grazing) on soil microbial community. Soil Ecology Society Conference.
Technical Abstract: The effects of nutrient inputs and forage utilization on soil carbon stocks and the soil microbial community is important in developing sustainable production systems. In this study, we sampled plots with varying forage utilization that were fertilized with either inorganic N-P-K or high broiler litter. Forage utilization treatments included unharvested (vegetation is cut and left in place in October), hayed (every 28 d), light and heavy cattle grazing pressure. Previous work at these plots indicated that organic C was increasing at normal rates under unharvested and haying, but at very high rates with both cattle grazing treatments. The gradient of organic C due to management has also led to an increase in soil microbial biomass and potentially mineralizable carbon. The current study is using phospholipid fatty acid biomarkers to determine if the increase in soil carbon and microbial biomass has been accompanied by a shift in composition of the microbial community. The hypothesis proposed by Bardgett that low grazing leads to `slow cycles' dominated by fungi while high grazing leads to `fast cycles' dominated by bacteria, will be tested.