ABSTRACT
Plastic mulch is used in various crops production in order to increase yield, extend growing season, weed control, increase fertilizers efficiency and improve soil conditions. However, since such plastics removal and disposal represent not only an additional cost, but also a source of environmental pollution, interest in starch-based materials as a viable alternative for this and other agricultural applications has raised in the last years. In this regard, films based on starch present several advantages: biodegradability, renewable-resource based and relatively low cost. The present work exhibit the results obtained in the development and study of biodegradable
materials based on cassava starch reinforced with cassava bagasse, evaluating their biodegradability in soil and the effects of their exposure to UV -visible light cycles (photo-periods) for 60 days. Fibre inclusion resulted in more opaque and coloured films, with water vapour permeability a 53% higher, and increased maximum tensile strength and elastic modulus. During storage no changes in both optical properties and solubility of the films were observed. However, the materials showed signs of aging as its rigidity and crystallinity increased. Films without fibre addition showed a marked rise in the elastic modulus and maximum stress at break while their elongation at break decreased; such effects were less noticeable in reinforced films. In order to evaluate the materials biodegradability, samples were buried in fertile soil under controlled environmental conditions. After 42 days, it was observed that both reinforced materials and controls had a weight loss greater than 60%, evidencing their biodegradability. In conclusion, it is possible to develop eco-compatible cassava starch reinforced materials with potential agronomic uses.
Keywords
Cassava starch; biodegradable materials; mulch; agronomic use
