Zinc slow-release systems for maize using biodegradable PBAT nanofibers obtained by solution blow spinning

Zinc is one of the most important micronutrients used in agriculture, especially in tropical soils that are Zn-deficient and thus adsorb Zn applied from fertilizer, making it less available to plants, a problem that causes plant deficiencies. Therefore, slow-release systems are an alternative to minimize the sorption process of micronutrients in soil and ensure their availability to plants. In this work, micronutrient delivery systems comprised of Zn-loaded poly(butylene adipate‐co‐terephthalate) (PBAT) nanofibers were prepared by solution blow spinning (SBS). Scanning electron microscopy (SEM) results showed that by controlling process variables such as Zn content, air pressure and polymer concentration, PBAT nanofibers with diameters ranging from 306 to 380 nm were produced. Nanofibers properties were also studied by x-ray diffraction (XRD) and thermal analyses (TGA and DSC). Zinc addition reduced both the crystallinity and thermal properties of the nanofibers. The Zn release profiles in water were much slower in comparison with the control (ZnSO4) fertilizer. Maize (Zea mays) with and without slow-release systems were cultivated to assess their effect on plant nutrition and shoot yield. Nanofibers were efficient in releasing Zn in order to meet its nutritional demands. Zinc application via nanofiber promoted dry mass production similar to the control, even at the lowest doses applied, which helped increase Zn availability in soil. Results demonstrated that the spun PBAT nanofibers slowly released Zn to the soil in a controlled fashion, demonstrating that the Zn release systems developed can be used as a promising tool to improve the efficiency of fertilizers in agriculture.