Influence of Hydrogel and Zinc Oxide Nanoparticles on the Germination and Establishment of Chenopodium quinoa.

The aim of this study was to assess the influence of hydrogel and zinc oxide nanoparticles on quinoa germination and establishment. Various doses of a commercial potassium-based hydrogel (0, 5, 7, and 9 g), each dissolved in one liter of rainwater, were applied. Additionally, 1.5 g of zinc oxide nanoparticles (ZnO-NP) and pre-crushed nitrogen fertilizer, at a rate of 1.6 kg/ha, were added to the solution to achieve a homogeneous mixture. Following the application of hydrogel in the 10-linear-meter rows corresponding to each treatment area in every block, 25 seeds per linear meter of the "Blanca de Juli" quinoa cultivar were sown with a 4 cm spacing between the seeds. Subsequently, a thin layer of soil, approximately 0.5 cm thick, was used to cover the seeds. Ten seedlings were randomly selected and labeled for subsequent evaluations. The experimental design employed in this research was a completely randomized block design. The collected data underwent an analysis of variance, and the means of all the treatments were compared using Tukey's test with a 5% probability. Height and diameter evaluations of the plant neck were conducted every 45 days. The doses used in this study (5, 7, and 9 g of hydrogel per liter of water) significantly enhanced seed germination and increased the number of plants per linear meter (from 82.00 to 90.33) compared to the control dose without hydrogel (14.66), which resulted in an average of one plant per linear meter.

Degradation of Hydrogels Based on Potassium and Sodium Polyacrylate by Ionic Interaction and Its Influence on Water.

Hydrogels are a very useful type of polymeric material in several economic sectors, acquiring great importance due to their potential applications; however, this type of material, similarly to all polymers, is susceptible to degradation, which must be studied to improve its use. In this sense, the present work shows the degradation phenomena of commercial hydrogels based on potassium and sodium polyacrylate caused by the intrinsic content of different types of potable waters and aqueous solutions. In this way, a methodology for the analysis of this type of phenomenon is presented, facilitating the understanding of this type of degradation phenomenon. In this context, the hydrogels were characterized through swelling and FTIR to verify their performance and their structural changes. Likewise, the waters and wastewaters used for the swelling process were characterized by turbidity, pH, hardness, metals, total dissolved solids, electrical conductivity, DLS, Z-potential, and UV-vis to determine the changes generated in the types of waters caused by polymeric degradation and which are the most relevant variables in the degradation of the studied materials. The results obtained suggest a polymeric degradation reducing the swelling capacity and the useful life of the hydrogel; in addition, significant physicochemical changes such as the emergence of polymeric nanoparticles are observed in some types of analyzed waters.