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.

Agricultural Applications of Superabsorbent Polymer Hydrogels

“…It is known that SAPs based on natural polymers are superior to those based on synthetic polymers in biodegradability but inferior in water uptake and soil amendment efficiency [ 23 ]. These basic features of SAPs based on nanocellulose were confirmed in [ 76 ], where nanoscale cellulose-based superabsorbents were prepared using the (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-mediated oxidation method [ 77 , 78 ] from Bleached Eucalyptus Kraft (BEK) pulp (Australian Paper, Maryvale, QLD, Australia) with a chemical composition of cellulose (78.8% ± 0.8), hemicellulose (17.7% ± 0.4), lignin (3.2% ± 0.1), extractives (0.3% ± 0.1), and ash (0.2% ± 0.1) [ 79 ]. The properties of the prepared nanocellulose-based SAP were compared to those of a commercial anionic PAM-based SAP.…”

“…The properties of the prepared nanocellulose-based SAP were compared to those of a commercial anionic PAM-based SAP. It was shown for clay loam (CL) and sandy (SD) soil that both commercial and nanocellulose SAPs improved the water retention ( Figure 20 a), decreased soil density ( Figure 20 b) and increased soil porosity ( Figure 20 c), but all these effects are more pronounced for the synthetic SAP than for the cellulose-based one [ 76 ].…”

Modulating superabsorbent polymer properties by adjusting the amphiphilicity

“…As the world progresses towards a renewable future, cellulose is becoming increasingly popular as a platform molecule for superabsorbent materials due to its low-cost, biocompatibility, and ability to modify for desired applications ( Alam et al, 2019 ; Mendoza et al, 2019a ; Barajas-Ledesma et al, 2020 ; Zainal et al, 2021 ). In our previous work we have investigated the synthesis and properties of TEMPO-oxidized cellulose-based hydrogels for agricultural and biomedical applications ( Mendoza et al, 2019b ; Curvello et al, 2019 ; Barajas-Ledesma et al, 2020 ; Hossain et al, 2021 ; Barajas-Ledesma et al, 2022 ).…”

Functionalized Cellulose Sheets with Fertilizers Applied as Multimodal Agricultural Supports for Seedling Cultivation

“…24−30 The fiber structure has also been explored for water retention and controlled release of fertilizers, such as nitrogen (N), phosphorus (P), and potassium (K), for better development of seeds and seedlings, thus generating plants with greater stem height and number and size of leaves. 31,32 From micro-to nanoscale fibrillar structure, it is possible to control nutrient release and water retention. 33,34 In addition to the fibrillar structure, the possibility of cellulose regeneration enhances the application of natural fibers in the controlled release of nutrients, as reported in the literature.…”

“…The fiber structure has also been explored for water retention and controlled release of fertilizers, such as nitrogen (N), phosphorus (P), and potassium (K), for better development of seeds and seedlings, thus generating plants with greater stem height and number and size of leaves. , From micro- to nanoscale fibrillar structure, it is possible to control nutrient release and water retention. , In addition to the fibrillar structure, the possibility of cellulose regeneration enhances the application of natural fibers in the controlled release of nutrients, as reported in the literature . In this way, the fibers are used to compose materials for agricultural applications such as mulch, , mats, − superabsorbents, , composites, − and papers. , These studies have demonstrated the efficiency of fibers in promoting the proper release of nutrients for plant growth against the backdrop of high demand of fertilizers for global food production. , …”