Influences of Energy Cane Residue Management Practices on Soil C Dynamics.

The Lower Mississippi Alluvial Valley is a robust agricultural region capable of growing a wide array of crops.  Public and private investments in bioenergy are concerned not only with efficiently converting crops into fuels but also the carbon footprint of bioenergy crop production.  Soil carbon is the largest terrestrial pool of carbon and a vital component of the carbon footprint of bioenergy crop production.  Soil carbon dynamics associated with bioenergy crop production can be influenced by several management factors, and with energy cane production post-harvest disposal practices for residual biomass can affect soil C dynamics.  At a site in northeastern Louisiana, a test of post-harvest residue management for energy cane was conducted.  Treatments consisted of: (1) a control in which residue was left at the soil surface, (2) raking residue from the beds and depositing into furrows between beds, and (3) burning the residue.  Soil CO₂ efflux, residue decomposition, labile C, potential C turnover rates, microbial biomass C, and microbial activity were monitored throughout the year.  Results of these measurements will be presented.