Thermoplastic starch (TPS) from agricultural waste consisting of different amylose/amylopectin ratios was blended with polypropylene (PP) for degradation studies. The agricultural waste material was obtained from seeds and tubers with low starch contents of approximate to 50%. Non-Fickian behavior was observed for the water absorption test, and water uptake increased with increases in amylopectin content. The biodegradation was assessed based on the extent of carbon conversion, and was found to be dependent on the water absorption behavior and molecular structure of the starch component. Outdoor soil burial showed greater weight loss and deterioration in tensile properties compared to indoor soil burial. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013