Biodegradação de fertilizantes de eficiência melhorada baseados em carboximetilcelulose/ quitosana/zeólita incorporados com macro e micronutrientes

Abstract

Due to population growth, there is a need to increase food production to meet demand. Consequently, the use of fertilizers is rising, making it possible to increase productivity without expanding the agricultural area. Due to the high mobility of ions in the soil, the overuse of fertilizers has as a principal consequence the contamination of the soil, rivers, lakes, and aquifers. To overcome this problem, it is proposed to use enhanced efficiency fertilizers (EEF), making the fertilizer available more slowly to plants, reducing losses and contamination. The commercial materials available on the market use non-biodegradable polymers to cover the fertilizer, causing the accumulation of residues in the soil. An alternative to these polymers is those of natural origin and biodegradable. Thus, the objective of this work was to evaluate EEF materials developed in the group of polymeric materials and biosorbents (Lab. MPB). These materials are constituted by chitosan and carboxymethylcellulose and macro-enriched zeolite (K, N), and micronutrients (Zn, Cu, Mn, Fe). The zeolite was enriched with nutrients by the sorption technique, and the films were obtained by the casting technique, followed by pressing with temperature. The biodegradation was evaluated for 80 days following the ABNT 14283 standard with modifications. The biodegradation of the materials is related to the production of CO2. Based on the evolution of CO2, the developed materials presented a biodegradation profile superior to the commercial Basacote material. Also, we observed that micronutrients might have inhibited the biodegradation of the materials since the biodegradation was higher for material with only macronutrients. FTIR analyses showed that the material after biodegradation still presents characteristic bands of the polymers and the KNO3 fertilizer, which may indicate that only a portion of the nutrient was released in the medium. Thus, the developed materials have great potential to be applied as EEF material.