Hydrogel Based on Cashew Gum and Polyacrylamide as a Potential Water Supplier in Mombaça Grass Pastures: A Sustainable Alternative for Agriculture

Abstract

Hydrogels are water-absorbing polymers that can hydrate forage plants in the soil. The objective was to evaluate the replacement of synthetic hydrogels derived from petroleum with biodegradable hydrogels in Mombaça grass pastures (Megathyrsus maximum). The experimental treatments consisted of no hydrogel (NH); synthetic commercial hydrogel (CH), made from a synthetic polyacrylamide product; and biodegradable test hydrogel (TH), obtained from cashew gum (Anacardium occidentale). The experimental design consisted of randomized blocks with five replications and three treatments. The morphogenesis, production, chemical, and mineral composition of the Mombaça grass pasture were assessed. The data were subjected to analysis of variance and mean comparison using the Scott–Knott test at 5% probability. The leaf elongation rate showed 42.3 mm day−1 in the treatment TH, which was higher (p < 0.05) than NH (35.0 mm day−1). The green leaf mass yield was higher in TH than in NH and CH. On the other hand, hydration had no effect on the chemical composition. The mineral composition of Mombaça grass showed more Zn when TH was used. It can be concluded that biodegradable hydrogels can replace synthetic commercial hydrogels in pastures.