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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.

Carboxylated nanocellulose superabsorbent polymers (SAP) can be used to increase soil water retention in agriculture. The benefits investigated are influenced by the superabsorbent structure, composition and application rate.In this study, TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl)-oxidised nanocellulose superabsorbents were prepared using three different drying techniques: freeze-dried, and oven-dried at low and high temperatures. The swelling capacity in soil water extracts was measured and compared to deionised water. Soil was amended with different application rates of these superabsorbents to evaluate the effects on water retention, microbial community and their biodegradation.The absorption performance of nanocellulose superabsorbents is affected by the concentration and type of salts in the soil water extracts. Oven-dried at 50 °C SAP presents the highest ionic sensitivity attributed to its large number of accessible carboxylate groups. The water retention of the soil treatments increases with increasing application rate. Soil treated with the freeze-dried superabsorbent shows the highest water retention, whereas those amended with the 50°C oven-dried SAP remain moist the longest. The biodegradation rate of these materials depends on the application rate and nutrient availability. Carboxylated nanocellulose superabsorbents emerge as highperformance biodegradable materials for agricultural use, able to replace the current nonbiodegradable petrochemical-based superabsorbents. INTRODUCTIONWater is critical for agricultural production and food security. Irrigated agriculture uses about 70% of the water available for human consumption worldwide and accounts for 59% of the total fresh water in Australia (Organisation for Economic Co-operation and Development; Department of Agriculture 2020). Water availability has been impacted by climate change, drought and water shortage; its decrease has affected world agricultural development in recent years. According to Müller C. (2010), agricultural yields will decline between 2 -15% over the next 30 years due to climate change. Hence, the efficient use of water resources is crucial for the long-term sustainability of the agricultural industry.One strategy to optimise water retention in soils and hence making it more available to crops, is the use of superabsorbent polymers (SAPs) (Zohuriaan-Mehr et al. 2008). SAPs are three-dimensional (3D) networks of linear or branched hydrophilic polymers physically or chemically cross-linked (Guilherme et al. 2015). SAPs can absorb and hold water at hundreds of times their own weight and remain stable in their swollen state (Ahmed 2015;Ghorbani et al. 2019;Shen et al. 2016;Gross JR 1990). They have been extensively used in many applications including biomedicine (Curvello et al. 2019), food and beverages (Shewan and Stokes 2013), personal care and hygiene products (Bashari et al. 2018). In the agricultural and horticultural industries, SAPs have a range of applications which includes seed coatings, seed additives and root dips (Zoh...

The COVID-19 pandemic has highlighted the need for diversity in the market and alternative materials for personal protective equipment (PPE). Paper has high coatability for tunable barrier performance, and an agile production process, making it a potential substitute for polyolefin-derived PPE materials. Bleached and newsprint papers were laminated with polyethylene (PE) coatings of different thicknesses, and characterised for their potential use as medical gowns for healthcare workers and COVID-19 patients. Thicker PE lamination improved coating homogeneity and water vapour resistance. 49 GSM bleached paper with 16 GSM PE coating showed high tensile and seam strength, and low water vapour transmission rate (WVTR). Phi-X174 bacteriophage testing revealed that paper laminated with 15 GSM coating hinders virus penetration. This research demonstrates that PE laminated paper is a promising material for low cost viral protective gowns.