An evaluation of the controlled release of ammoniacal nitrogen from residual cellulose/polyvinyl alcohol hydrogels as an alternative to traditional fertilization processes

Abstract

Soil fertilization improves yield and quality of produce, but nutrient loss from fertilized soil produces alterations in the ecosystems (e.g., eutrophication); it also increases costs in the agribusiness. In this research, we developed a device from residual cellulose/polyvinyl alcohol hydrogel for the controlled release of ammoniacal nitrogen in soil. Total Kjeldahl Nitrogen (TKN) method was used to determine the fraction of nitrogen released, and the effect of the device on a bioindicator (Zea mays) was studied in greenhouse conditions. Structural damage to the device after its application to soil was analyzed using scanning electron microscopy (SEM). Kjeldahl tests showed the device released less than 15% of total nitrogen across a 60 day evaluation period, displaying a Fickian diffusion pattern. Seedlings produced two times more biomass in device-fertilized soil.

Keywords

• hydrogel
• residual cellulose
• poly(vinyl alcohol)
• controlled release
• ammoniacal nitrogen