Functional Hydrogels for Agricultural Application

Abstract

Ten different hydrogels were prepared and analyzed from the point of view of their use in soil. FT-IR spectra, morphology, swelling ability, and rheological properties were determined for their characterization and appraisal of their stability. The aim was to characterize prepared materials containing different amounts of NPK as mineral fertilizer, lignohumate as a source of organic carbon, and its combination. This study of stability was focused on utility properties in their application in soil—repeated drying/re-swelling cycles and possible freezing in winter. Lignohumate supported the water absorbency, while the addition of NPK caused a negative effect. Pore sizes decreased with NPK addition. Lignohumate incorporated into polymers resulted in a much miscellaneous structure, rich in different pores and voids of with a wide range of sizes. NPK fertilizer supported the elastic character of prepared materials, while the addition of lignohumate shifted their rheological behavior to more liquid. Both dynamic moduli decreased in time. The most stable samples appeared to contain only one fertilizer constituent (NPK or lignohumate). Repeated re-swelling resulted in an increase in elastic character, which was connected with the gradual release of fertilizers. A similar effect was observed with samples that were frozen and defrosted, except samples containing a higher amount of NPK without lignohumate. A positive effect of acrylamide on superabsorbent properties was not confirmed.

Assessment of energy cane bagasse-derived cellulosic microfiber hydrogels on the growth of potted chili peppers

“…Interestingly, both CMH hydrogels exhibited a surprising surge in water absorption (within 10–20 min) during the second cycle, surpassing their initial values of cycle 1. This phenomenon, attributed to potential structural changes during the drying process, underlines the dynamic nature of hydrogels and their ability to adapt to repeated wetting and drying cycles [ 48 , 58 ]. Additionally, chitosan content within CMHs seems to play a crucial role in WRV, with optimal water retention observed at 35% chitosan in CMH65.…”

Editorial for Special Issue: Advances in Smart and Tough Hydrogels

“…In addition, Martina's group employed intelligent superabsorbent polymeric hydrogels, utilizing them as both a water reservoir and a supplier of mineral and organic nutrients with the aim of enhancing soil quality. In this case, the incorporation of NPK fertilizer reinforced the flexibility of the hydrogels, whereas the inclusion of lignohumate induced a shift in their rheological properties towards a more liquid-like behavior [11]. In light of the growing interest and attention toward hydrogel-based smart soils and relevant sustainable devices for tackling agricultural and environmental challenges, we recommend considering the following perspectives of smart hydrogels: (i) enhancing moisture retention and irrigation efficiency, (ii) implementing controlled nutrient release mechanisms, (iii) integrating soil health monitoring and environmental protection, (iv) ensuring compatibility with soil microorganisms, and (v) exploring additional avenues [12].…”

A Comprehensive Review of Radiation-Induced Hydrogels: Synthesis, Properties, and Multidimensional Applications

“…In 2023, a research group highlighted the significance of biopolymer-based hydrogels in agriculture and their water-holding capabilities, emphasizing their dual role as soil conditioners and slow-release mechanisms for fertilizers in challenging conditions [ 155 ] (as shown in Figure 12 b,c). They discussed the use of hydrophilic hydrogels applied during planting or seed coating, primarily serving as carriers for nutrients and enhancers of soil quality [ 156 , 157 ]. Key considerations when selecting a hydrogel for soil enhancement include superabsorbent properties, biodegradability, and chemical crosslinking.…”