Application Of Superabsorbent Polymers Research Articles

Super absorbent polymer (SAP) on water‐salt transport in saline alkali soil: Effects of dosage, height and thickness

AbstractSoil salinisation is a pervasive form of land degradation posing a significant threat to the global environment. Saline soil, covering roughly 10% of the total land area, represents a crucial reserve of land resources. The use of super absorbent polymer (SAP) impacts capillary water movement through the soil because of its exceptional water absorption and retention capabilities. SAP is expected to influence the intricate water‐salt migration processes and their redistribution within soil. This study employed soil column experiments to investigate the impacts of varying SAP dosages (A), heights (B) and thicknesses (C) on soil water and salt transport in the Tianjin Binhai New Area, China. The main findings showed that: (1) average capillary water rise rate decreased with SAP dosage increase. The groundwater recharge trend in time was like that of capillary water rise height; (2) SAP usage increased water and salt content on the application layer and reduced surface soil salt accumulation; (3) the best SAP combination for application was 1.1% SAP at 17–18 cm from the groundwater level. This study provides basic effective SAP application strategies for preventing soil salinisation.

Investigation of the effect of superabsorbent polymer application on soil moisture and plant growth

As climate change continues to affect the environment, drought management has become more critical in agri-food production. Farmers are now looking for alternative drought management methods that are easy to apply. In this sense, superabsorbent polymers (SAPs) were proposed as an alternative soil conditioning and drought management tool within this study. To test the efficiency of a developed SAP in terms of soil conditioning and plant growth promotion with different soil types and extreme drought conditions, long-term soil and greenhouse experiments were carried out in at least 4 replicates. The plant growth was monitored by 4 different growth indicators using wheat as a model plant. Plant growth indicators demonstrated that shoot dry matter, spike length, and grain yield were enhanced up to 24%, and 11.6% using different amounts of SAP at varying drought conditions. The study set forth and exemplary of superabsorbent polymer use in agriculture and useful in dose adjustment and understanding the drought-dose relationship in these types of polymers.

Superabsorbent Seed Coating and Its Impact on Fungicide Efficacy in a Combined Treatment of Barley Seeds

The technology of seed coating with superabsorbent polymer (SAP) has the potential to mitigate the negative impact of drought on seed germination and crop establishment. However, their application on the seed surface can affect the effectiveness of pesticides used for seed treatment in the protection against phytopathogens. In our work, the influence of the Aquaholder®Seed polymer coating on the effectiveness of fungicides in the protection of germinating seeds of spring barley cv. Bojos and Laudis against the fungal pathogen Bipolaris sorokiniana was studied. One-half of the seeds were first treated with fungicides, and then a polymer was applied. Fungicide efficacy was evaluated in a Petri dish test and pot test under the pathogen attack. Seed coating with SAP did not negatively affect fungicide efficacy. The percentage of germinated seeds, seedling emergence, plant height, and symptoms of the disease in the fungicide-treated variants were not significantly changed by the SAP application. Moreover, in cv. Laudis, the application of SAP alone partially protected germinating seeds against pathogen attack. The amount of pathogen DNA in plant tissues of cv. Laudis was not significantly different among seed treatments, while in cv. Bojos, the pathogen DNA increased in seeds coated with SAP alone but decreased in combined treatment with fungicides. These results demonstrated that SAP seed coating does not negatively affect the efficacy of fungicides used for seed protection against fungal pathogens.

Porous superabsorbent composites prepared from aqueous foam template and application evaluation.

Rapid water absorption is very important for the application of superabsorbent polymers under dry or semi-dry conditions, but there are currently few relevant studies. In this context, a novel porous superabsorbent of chitosan-grafted acrylic copolymer-2-acrylamido-2-methylpropanesulfonic acid/sapindus mukorossi pericarp/calcined oil shale semi-coke (CS-g-P(AA-co-AMPS)/SMP/COSSC) was prepared by a green and convenient foam template method, which was triggered by redox polymerization. The rich pore structure of the porous superabsorbent was conducive to accelerating the water absorption rate. It only took 15 min to reach a swelling capacity of 650 g g-1 in distilled water. Soil experiments show that even with the addition of 0.5 wt% porous superabsorbent, the soil water retention time can be extended to 7 days. Finally, it was applied to the growth of cabbage seeds and it was found that the growth was significantly improved. Based on these excellent properties, we expect to provide a valuable reference for the preparation of fast-absorbing materials through the green water-based foam template method, contributing to sustainable agriculture.

Effect of integrate water shortage and soil conditioners on water productivity, growth, and yield of Red Globe grapevines grown in sandy soil

Abstract Water-deficit problem in Egypt due to the scarcity of water resources and climatic changes causes significant stress on all crops such as grapevines. Using soil conditioners like superabsorbent polymer (SAP) and Bentonite (BENT) can reduce water problems due to their abilities to store more water and improve the physical and chemical characteristics of soil. A field experiment with a completely randomized block design was carried out in three replicates at a private farm in Minia Governorate, Egypt to assess the influence of SAP and BENT on growth, yield, and water productivity (WP) of Red Globe grapevines as well as some physical and chemical properties of soil under water deficit regime (75 and 50% of water requirement) and full irrigation 100% of water requirement (control) during 2021 and 2022 seasons. The vines were 13 years and irrigated by a drip irrigation system in sandy soil. The studied soil was treated with different doses of SAP (250 and 500 g/vine) and BENT (200 and 400 g/vine). The obtained results showed that reducing irrigation to 75 and 50% of the water requirements led to significant decrease in vegetative growth metrics, readings for SPAD, leaf nutrients (N, P, and K), yield and its constituents as well as the physical and chemical properties of the berries compared to full irrigation. Adding SAP and BENT significantly increase the aforementioned characteristics under water deficit conditions. Application of SAP and BENT was the most effective way to mitigate the negative effects of water shortage on growing Red Globe grapes in sandy soil. SAP gave better results than BENT. Thus, applying superabsorbent 500 g/vine with deficit irrigation 75% of water requirements was a successful treatment in producing an economical yield and berries with fairly high quality and had a positive effect in enhancing WP as well as it proved to be a promising method to improve sandy soil characteristics.

Properties and valuable applications of superabsorbent polymers: a comprehensive review

Properties and valuable applications of superabsorbent polymers: a comprehensive review

On the factors affecting the swelling behavior of superabsorbent polymers in cement-related environment

Superabsorbent polymer (SAP) has water absorption and release behavior and can be used as internal curing or self-healing additive in cement-based materials. However, SAP has complicated and changeable swelling behaviors in cement-based materials, which has not been fully investigated. In present work, an AA-AM co-polymerized SAP was synthesized, and potential factors related to cement-based materials, including water-cement ratio and binder type, superplasticizer content, early hydration time, mixture stirring rate, temperature and pressure, were systemically investigated. Results indicated that maximum absorptivity of SAP decreased gradually with hydration time. SAP presented the highest absorptivity in FA and GGBS blended cement binder, and the lowest absorptivity in geopolymer, although the water-binder ratio is the same. The swelling behavior of SAP is related to the PCE content, and maximal SAP absorptivity first rises and then falls as PCE content increases. As the stirring rate increases, SAP's maximal absorptivity increases, due to the “Bernoulli's effect”. In addition, the absorptivity of SAP showed temperature and pressure sensitivity, which was improved by the increased temperature or decreased external pressure. The findings in present work suggest that potential factors related to cement-based environment should be comprehensively considered for practical application of SAP in concrete engineering.

Synthesis and application of super absorbent polymers synthesized with ammonia solution and diatomaceous earth with low toxic residues

Water-soluble harmful components that remained in SAPs pose potential risks to crop growth, resulting in decreased seed germination rate, reduced yield, and inhibited root system growth. These factors restrict its widespread use in agriculture and forestry. In this study, a new type of super absorbent polymers (AD-SAP) with low residual acrylic acid and sodium ions was synthesized by using ammonia solution instead of strong alkali sodium hydroxide for neutralization and adding modified diatomaceous earth to improve the grafting efficiency. The prepared samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS), and the influence of the dosage of acrylic acid and ammonia solution used for preparation on the residual content of water-soluble harmful components in AD-SAPs was investigated. When 28% of acrylic acid, 24% of ammonia solution, and 5% of diatomaceous earth were used for synthesis, the residual acrylic acid content in AD-SAP was 0.03%, and the sodium ion content was reduced to 0.12 g/kg, which is much lower than the three commercially available SAPs. However, its water-absorption capacity has not decreased and its salt resistance has improved. The water absorption ratio of AD-SAP is 578g/g, and the salt-absorption ratio is 87 g/g. Pot experiments showed that AD-SAP eliminated the adverse effects of commercial SAPs on crop growth. The research provided technical support for the production of SAPs, and offer scientific guidance for how to mitigate the adverse effects of SAPs on crop growth.

Vegetative growth and flowering of dragon fruit species according to branch pruning management and application of superabsorbent polymer

The cultivation of dragon fruit has been standing out considerably in Brazil, however, although on the rise, information onthe cultivation of this fruit, such as pruning management in young orchards and the use of superabsorbent polymer in thecrop, is scarce. In this sense, in order to remedy producers’ obstacles regarding the management of orchard formation, theobjective of this study was to evaluate the influence of pruning management and the efficiency of hydrogel in the vegetativeand reproductive development in two different species of dragon fruit (Selenicereus undatus and Hylocereus polyrhizus),in addition to defining the best dose of the polymer to be used in the crop. The work was developed at IFSULDEMINAS –Machado Campus. The design used was the randomized block design, in a factorial scheme (2x2x3), the first factor beingcomposed of the two species of dragon fruit, the second, by two cladode pruning levels (with and without pruning), and thethird, by three doses of the superabsorbent polymer Hydroplan-EB® (0; 1.5; 4.5 g plant-1). The following characteristicswere evaluated: number and length of shoots; total number of flowers; total number of fruits; number of aborted flowers;picking percentage; mean fruit mass; longitudinal and transverse diameter of fruits; peel thickness; pulp yield; peel massand productivity. The practice of cladode pruning, as well as the application of the superabsorbent polymer, did not influencemost of the characteristics evaluated. Further studies should be conducted to delve deeper into the management techniquesused in this study.

Alleviation of Water-Deficit Stress on Seed Germination of Barley and Fenugreek in a Sandy Soil Using Superabsorbent Polymer

Water deficit is one of the major limiting factors of seed crop germination and productivity. Consequently, superabsorbent polymers (SAPs) are among several technologies that enhance water use efficiency, leading to worthy seed germination. The objective of this study was to investigate the potential effect of three rates of SAPs (0.0%, 0.5%, and 1.0% w/w) on the seedling emergence of barley and fenugreek sown in a sandy soil using three replicates in a randomized complete block design. Outdoor pot experiments were conducted in Aswan Province, Egypt. The differences in the final germination percentages (FGPs) were not significant for both seeds, while the application of SAPs enhanced the seedling germination index (GI) with significant differences for both crop seeds. The application of SAP at 0.5% gave the highest GI for barley (2.47 day−1) and fenugreek (2.66 day−1) seeds. The sigmoidal function effectively described the cumulative germination percentage rates for both seeds as a function of time under the SAP levels with R2 greater than 0.992. The maximum rates were 69.4 and 64.6 day−1 for barley and fenugreek seeds at SAP 0.5%, respectively. The corresponding rates for 0.0% SAP were 11 and 12 day−1. The water germination efficiencies (WGE) were 27.76 and 30.04 cm−1 for 0.0% and 0.5% SAP for barley, while they were 23.07 and 29.9 cm−1 for fenugreek. Accordingly, SAPs could represent a promising solution for increasing moisture conservation for seed germination in a sand soil. For strategic management, barley is recommended for growth over fenugreek in a semidried soil.

Effect of Superabsorbent Polymer Application on Soil Hydraulic Properties, Growth, Yield, and Water Use Efficiency of ‘Early Sweet’ Grapevine (Vitis vinefera) under Different Irrigation Levels

Effect of Superabsorbent Polymer Application on Soil Hydraulic Properties, Growth, Yield, and Water Use Efficiency of ‘Early Sweet’ Grapevine (Vitis vinefera) under Different Irrigation Levels

Early-Age Cracking Potential of Fly Ash High Performance Concrete Internally Cured with Super Absorbent Polymers

Abstract Early-age cracking is problematic for high performance concrete (HPC) made with a low water/binder ratio. The application of fly ash (FA) as a cement replacement can contribute to reduced CO2 emission and clinker factor, as well as improved durability of HPC. Super absorbent polymers (SAPs) were also applied for better curing and a higher rate of hydration to optimize the FA HPC. The current study utilized a temperature stress test machine to investigate the early-age cracking potential of FA HPC with internal curing by SAPs. Test results and the related analyses suggested that the introduction of internal curing alleviated the autogenous shrinkage, restrained stress, as well as tensile creep for HPC with 0 % and 20 % FA replacement level. The application of SAPs reduced the cracking potential of HPC with a low FA replacement level, whereas it aggravated the cracking when the FA replacement level was high.

Superabsorbent polymer and its effect on maize germination, emergence and genetic diversity of rhizosphere microorganisms

Abstract The application of superabsorbent polymer (SAP) for seed coating of agricultural crops is an innovative and promising method to effectively reduce plant stress during dry periods and thereby contribute to sustainable agriculture. However, due to the lack of experiments using SAP in field conditions in Central Europe, we focused on determining the effect of synthetic SAP, which was used for coating maize seeds, on the germination and emergence of these plants as well as on determining its impact on the genetic diversity of microbial communities in the maize rhizosphere for two consecutive years. The results showed that the growth parameters of coleoptiles and root systems of germinating maize plants at the very early development stage were biased in favour of SAP-coated seeds, and some values were statistically higher in the second year of evaluation. Similar observations were recorded in the assessment of maize emergence parameters. Also, these values were better when using SAP-coated seeds compared to the untreated controls. Plant height, dry weight, leaf tip number, and the Soil Plant Analysis Development (SPAD ) value were statistically higher in the second year of evaluation. The rhizosphere bacterial and fungal genetic diversity results did not confirm statistically significant differences between the SAP-coated and control maize seeds. They concern both alpha diversity indices and the results from multivariate statistical methods. Principal coordinate analysis results with cluster analysis show that the main factor influencing the microbial diversity in the maize rhizosphere was the collection date, especially the year of sampling than t he use of SAP-coated seeds.

Water Retention Characteristics of Superabsorbent Polymers (SAPs) Used as Soil Amendments

Superabsorbent polymers (SAPs) are used as a soil amendment for retaining water, but suitable methods for the application of SAPs have not yet been developed. Here, we characterized a variety of soil–SAP mixtures prepared using four different types of SAP in terms of their water absorption and release characteristics. The teabag method was applied to characterize the soil–SAP mixtures, except for measurements of the matric potential. The results showed that the variations in water absorbency among the four SAPs in isolation became insignificant when they were mixed with sandy soils. The rates of water released from the soil–SAP mixtures under heated conditions were mitigated with decreasing water content, which prolonged the time until desiccation of the mixtures. The water absorbency of the SAPs significantly decreased in salt solutions (KCl and CaCl2), but their absorbency mostly recovered following immersion in tap water. The soil–dry SAP mixtures retained a larger amount of water than the soil–gel SAP mixtures. Swollen SAPs predominantly retained water in the range of −0.98 to −3.92 kPa, suggesting that SAP induces a transition from gravitational water to readily plant-available water by swelling itself. SAPs barely increased the amount of plant-available water in a potential range of −3.92 to −98.1 kPa, but significantly increased the soil water at <−98.1 kPa. The soil water content increased with an increasing SAP application rate, whereas the proportion of plant-available water declined. Our findings indicated that the performance of SAPs depends on the pore space and a saline environment in the soil and that low SAP application rates are suitable for maximizing the water available to plants in sandy soils.

Enhanced pearl millet yield stability, water use efficiency and soil microbial activity using superabsorbent polymers and crop residue recycling across diverse ecologies

Under changing climate scenarios, developing sustainable adaptation strategies in agriculture will be obligatory. To understand the effect of carbohydrate-based superabsorbent polymer (SAP) and crop-residue mulch (CRM) on pearl millet productivity and water-use efficiency (WUE), field experiments were undertaken for three consecutive years at 11 different locations (representing ⁓30 % of the global pearl millet growing area). Eight treatments, namely, Control; CRM 5.0 t/ha; SAP 2.5 kg/ha; SAP 5.0 kg/ha; SAP 7.5 kg/ha; SAP 2.5 kg/ha + CRM 5.0 t/ha; SAP 5.0 kg/ha + CRM 5.0 t/ha and SAP 7.5 kg/ha + CRM 5.0 t/ha were evaluated. Co-application of CRM and SAP increased pearl millet grain and stover yield by up to ⁓45 % and ⁓36 %, respectively. Pearl millet responded significantly up to 2.5 kg/ha SAP application (with or without CRM) only. Further, soil microbial biomass carbon improved significantly with CRM (20 %) and SAP (10.9–12.1 %) individually and with simultaneous application of CRM and SAP (⁓30 %). Likewise, dehydrogenase, alkaline phosphatase, acid phosphatase, and urease activities also improved significantly due to the co-use of CRM and SAP. Positive effects of CRM, SAP, and their co-application were also witnessed on soil microbial (bacterial, fungal, actinobacteria) populations and water-use efficiency (WUE) across environments. Among the locations, New Delhi and Aurangabad were the most desirable and stable ecologies, whereas Bikaner and Vijayapur remained the least consistent. Hence, to tackle the moisture-stress problem under pearl millet production systems and to achieve stable productivity, greater WUE and better soil microbial activity, CRM 5 t/ha in conjunction with SAP 2.5 kg/ha may be recommended across diverse ecologies.

MODELLING OF POTATO CROP WATER PRODUCTIVITY AND YIELD RESPONSE UNDER SUBSURFACE DRIP IRRIGATION SYSTEM

The need for increased food production by applying low water quantity is pausing more challenges to farmers. The production of Irish Potatoes in Kenya in arid and semi-arid areas is challenging for most farmers due to low yields. The purpose of the study was to simulate potato crop water productivity. A field experiment was conducted at Egerton University during the 2021-2022 dry season. The effect of deficit subsurface drip irrigation allied with superabsorbent polymer soil amendment on growth parameters and yield of potatoes was evaluated. Twelve treatments composed of three water application levels 70%IL, 85%IL,100%IL and four super absorbent polymer (SAP) application rates No SAP, 6 kg/ha, 10 kg/ha,and 14kg/ha laid in factorial experimental design were applied in December 2021 to May 2022 season. Irrigation was undertaken when the allowable water depletion reached 50%. The AquaCrop model was utilised to predict soil water content, biomass, canopy cover, dry yield, and water productivity (WP). The 100% water application level with 0kg/ha SAP was used in model calibration, whereas the remaining treatments were used to validate the model. The model simulated results compared with observed canopy cover, biomass and WP produced a good performance fit with R2 range of 0.86 to 0.98, root mean square error (RMSE) of 10.6%, NSE of 0.9, and Wilmot's degree of agreement of 0.98. However, the model underestimated the water content due to the application of SAP in the soil. Because the SAP improved soil characteristics relevant for water holding capacity without changing the physical texture and structure of the soil. The findings indicated that the combined effect of SAP and subsurface drip resulted in increased yield in deficit water application. The calibrated model was successfully applied in simulating WP and yield. The calibrated AquaCrop model can be applied in planning, operation and management of potato-irrigated farms that will lead to improved water productivity and yield in water constrained areas like semi-arid Kenya.

Improvement of Soil Quality and Pakchoi Performance Via the Application of Superabsorbent Polymer to Cd-Contaminated Acidic and Alkaline Soils

Improvement of Soil Quality and Pakchoi Performance Via the Application of Superabsorbent Polymer to Cd-Contaminated Acidic and Alkaline Soils

Response of root growth and distribution of maize plants to foliar-sprayed antitranspirant and soil-amended hydrogel polymer

Root growth and development of maize (Zea mays L.) is an important process in determining grain yield. The effects of combined fulvic acid (FA, potassium humate as FA source) and super absorbent polymer (SAP) uses on maize root growth and yield were studied. A 2×3 factorial field experiment was applied by combining two SAP doses (0, 45 kg ha-1) and three FA rates (0, 1, and 2 g L-1) over 2 yr. Super absorbent polymer was applied to upper 20 cm soil layer at sowing, and FA solutions (1 or 2 g L-1, corresponding to FA1 and FA2) were sprayed onto the canopy three times during growing season. Root parameters, including root biomass, root length density (RLD), root surface-area density (RSD), and root diameter, were determined in the top 40 cm soil layer. Relative to control plants, both chemicals significantly increased root biomass, but these effects were not significantly different from their combined use. Compared to individual FA or SAP treatment, combined applications increased RLD and RSD in 0-20 cm depth. The combined SAP and FA2 improved RLD at 0-10 cm by 32% compared to FA2 treatment alone and by 82% compared to non-chemicals control plots over 2 yr. Averaged root diameters also significantly increased in the 40 cm soil layer in FA and SAP treatments alone compared to control, but they were not significantly different with the combined treatment. Similar patterns were found for maize yield each year. The combined application of SAP (45 kg ha-1) and FA2 (2 g L-1) greatly increased root length density and biomass than their individual application, and it could be suitable for high production of maize grown under low rainfall conditions.

Development of Superabsorbent Polymer (SAP) Seed Coating Technology to Enhance Germination and Stand Establishment in Red Clover Cover Crop

Drought conditions after sowing threaten the seedling establishment of all seeds, including cover crops. Cover crops are commonly broadcast and, thus, are often susceptible to drought stress after sowing. Our hypothesis was that seed coating with superabsorbent polymers (SAPs) would enhance germination in the lab and stand establishment in the field by increasing water availability to single seeds. Red clover (Trifolium pratense L.) seeds were coated with the following selected SAP formulations at 2% of their seed weight: cross-linked potassium polyacrylate (PAL), cross-linked polyacrylamide-based polymer (PAM), PAM with graphite (PAM+G), and Starch-g-2-Propenoic acid (potassium salt) (STR). The water absorbency of each SAP formulation was >200 g water/g of polymer; STR had the greatest absorbency, at 352 g water/g of polymer. A seed coating method was developed, resulting in the uniform application of SAP from seed to seed. All SAP coating treatments increased germination compared to the 0% SAP coating in controlled environment studies in the lab. Three field trials were conducted for each seed coating treatment, providing a range of climatic soil conditions. Within each field trial, the STR with the greatest water absorbency had a higher stand for treatments sown by broadcasting followed by raking to incorporate seeds. The first two trials were conducted under more stressful conditions. PAM+G performed best in the first two trials by broadcasting seeds with no raking. Collectively, the selected SAP seed coating improved field stands compared to the non-treated controls.

Superabsorbent Polymers as a Soil Amendment for Increasing Agriculture Production with Reducing Water Losses under Water Stress Condition.

With an increasing population, world agriculture is facing many challenges, such as climate change, urbanization, the use of natural resources in a sustainable manner, runoff losses, and the accumulation of pesticides and fertilizers. The global water shortage is a crisis for agriculture, because drought is one of the natural disasters that affect the farmers as well as their country's social, economic, and environmental status. The application of soil amendments is a strategy to mitigate the adverse impact of drought stress. The development of agronomic strategies enabling the reduction in drought stress in cultivated crops is, therefore, a crucial priority. Superabsorbent polymers (SAPs) can be used as an amendment for soil health improvement, ultimately improving water holding capacity and plant available water. These are eco-friendly and non-toxic materials, which have incredible water absorption ability and water holding capacity in the soil because of their unique biochemical and structural properties. Polymers can retain water more than their weight in water and achieve approximately 95% water release. SAP improve the soil like porosity (0.26-6.91%), water holding capacity (5.68-17.90%), and reduce nitrogen leaching losses from soil by up to 45%. This review focuses on the economic assessment of the adoption of superabsorbent polymers and brings out the discrepancies associated with the influence of SAPs application in the context of different textured soil, presence of drought, and their adoption by farmers.