This work focuses on analysis and comparison of accelerated weathering of samples of polylactic acid reinforced with cellulose whiskers (PLA-CW), conducted in QUV chamber-Panel, and their subsequent exposure to biotic soil environment. The cellulose whiskers (microfibrils) were obtained from banana rachis and pseudostem Musa cavendish. Changes in thermal, structural and mechanical properties, due to degradation processes of PLA-CW, were studied using DSC, IR Spectroscopy, XRD, NMR, GPC and Mechanical test. The results show that the percentage of biodegradability in soil, based on CO₂ release, is higher for samples of PLA-CW that have been previously exposed to UV-photodegradation, which induces hydrolysis that stimulates the biodegradability of PLA-CW. The results indicate that PLA-CW has short half-life after biodegradation in soil and it is suitable for land disposal.