Yerba Mate (<i>Ilex paraguariensis</i>) Waste and Alginate as a Matrix for the Encapsulation of N Fertilizer

Abstract

In the present work, the recycling of yerba mate ( Ilex paraguariensis ) industrial byproducts into urea-containing capsules is described as an environmentally friendly strategy for nitrogen release into the soil. Yerba mate is an infusion traditionally drunk in various countries of South America. An extensive physical characterization of the capsules is reported: scanning electronic microscopy (SEM) and energy dispersive X-rays analysis (EDX), water gain and hygroscopicity, texture properties, measurement of water absorbency, differential scanning calorimetry (DSC), and Fourier transform infrared spectrometry (FT-IR). The capsule matrix had a yerba mate powder content ranging from 30% to 77%. Nitrogen release from the capsule-fertilizer and the capsule degradation were studied using soil (∼pH 7.50). All of the results indicate that yerba mate powder capsules with urea, as an example of an environmental friendly fertilizer, may be expected to have wide applications for the sustainable development of modern agriculture.