Biodegradation of a Nanocellulose Superabsorbent and Its Effect on the Growth of Spinach (Spinacea oleracea)

Abstract

In this study, spinach (Spinacea oleracea) plants were grown in two soils, a clay loam (CL) and a sandy (SD) soil, amended with two types of superabsorbent polymers (SAPs), nanocellulose and commercial, at different levels of soil moisture: 70, 40, and 20%. The effect of the superabsorbent on the soil properties, water management, and plant biomass was measured and compared to that in soils treated with a commercial anionic polyacrylamide-based SAP. Plant biomass is the highest in SD soil amended with a commercial superabsorbent. However, it decreases in the CL soil when a superabsorbent is applied, independent of the SAP type. This effect is magnified when a nanocellulose SAP is used; this is likely attributed to waterlogging stress and the fast biodegradation of this superabsorbent, where approximately 50% of the initial mass remains after 5 days of exposure. The use of a nanocellulose SAP as a water retention agent offers the potential for a much-needed sustainable solution for global agriculture. Future studies are needed to modify the structure of the nanocellulose SAP to inhibit its biodegradation and increase its benefits for agricultural use.