Objective:
Objective 1: Compare the effectiveness of selected indigenous fungal-bacterial populations in decomposing crop residues generated during the chopper-harvesting of green cane. Objective 2: Evaluate the influences of microbe placement, formulation, and adjuvant addition on the rate of degradation of post-harvest sugarcane residues. Objective 3: Compare the utilization of soil microbes for post-harvest residue removal to partial removal by mechanical means and complete removal by burning.

Approach:
Objective 1: Soil samples containing native populations of soil microorganisms will be collected from various sites in the Bayou Lafourche area from a: lawn, forest, sugarcane field that has been historically burned before or after harvest, and sugarcane field that has not been burned for at least three years. In addition to the native organisms, a commercial fungal-bacterial consortium from Sybron Chemicals, Inc. and an autoclaved, soil-only treatment (control) will be included. Soil (4g) from each source will be put into individual plastic containers (58 by 43 by 18 cm). Microbial efficiency will be based on changes in nutrient composition in the soil (samples at 30-day intervals with the final sample being taken at 120 days) and differences in residue quantities from time "0" to 120 days, expressed on a dry weight basis. Objective 2: Promising isolates identified above will be subjected to further greenhouse and laboratory evaluations. Mixes of these isolates will be applied to residue in containers as above. Comparisons will include placement of the microbial preparations above and below the residue as well as a treatment where the residue is lightly mixed with the soil/microbial mix. The influence of microbial formulation will also be evaluated. These bio-formulations are designed to aid in microbial dispersal and early survival in the target system. Finally, the use of starter energy sources such as molasses and/or nitrogen fertilizer will be evaluated. These materials may be applied externally or incorporated into the bio-formulations. Experimental duration and data collection will be the same as in objective 1. Objective 3: Immediately after harvest, microbial preparations showing promise will be applied to the residue in at least two commercial fields. The amount of residue in a 1-m2 area of each plot will be quantified at the time of treatment and at monthly intervals during the subsequent crop year until May. Soil samples will be collected to assess changes in the soil chemistry and biology. Microbial decomposition of the residue will be compared to a control (no removal), partial removal from the row top by mechanical means, and complete removal by burning. Cane development will be monitored (stalk population and height) at monthly intervals beginning in March and ending in September and the plots will be harvested mechanically to determine cane and sugar yields.