The decomposition rate of a crop residue is dependent upon its chemical composition: by assessing carbon to nitrogen ratios, nitrate, and ammonia concentrations, of various soils and residue types-- opportunity for improved soil fertility and increased crop nutrient uptake for proceeding crops in rotation exists.  Due to high cost and commercial unavailability, the objective of the study is the development of a cost-effective unit for use in aerobic incubation of residues for analysis.  Modeled after the dual-chambered microlysimeter model of the Nadelhoffer (1990) method, the designed unit is similar in function while significantly more affordable to produce.