Controlled fertilizer release via tunable poly(vinyl alcohol)/ammonium sulfate-coated nonwoven materials

In this study, nonwoven fabrics were coated with two different ammonium sulfate fertilizer loadings (27.75% and 55.50%) by using two different poly(vinyl alcohol) types (high and low molecular weight). The poly(vinyl alcohol) coating amounts were adjusted to 60 and 120g/m(2). In order to study the effect of poly(vinyl alcohol) crosslinking on fertilizer release, a glutaraldehyde (GA) crosslinking agent was used in two different ratios (GA/PVOH ratio: 0.01 or 1). A concentration of 0.01GA was insufficient for PVOH crosslinking, and water absorption capacity was reduced with increasing poly(vinyl alcohol) and glutaraldehyde loading amount. Fertilizer release was affected mostly by molecular weight and loading amounts of poly(vinyl alcohol) and fertilizer. It was possible to achieve controlled fertilizer release when the nonwoven fabric was coated at 120g/m(2) with high molecular weight poly(vinyl alcohol) containing 55.50% ammonium sulfate fertilizer in the absence of glutaraldehyde.