Article

Constructing Slow-Release Formulations of Ammonium Nitrate Fertilizer Based on Degradable Poly(3-hydroxybutyrate)

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  • Federal Research Center “Krasnoyarsk Science Center of Siberian Branch of Russian Academy of Sciences"
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... Controlled (or slow) release fertilizers (CRFs) are fertilizer products with embedded nutrients that are released to the soil in pace with plant growth requirements (Azeem et al., 2014). As a consequence, CRFs provide corollary benefits by mitigating nutrient run-off with associated environmental impacts of ground water contamination, eutrophication of surrounding water bodies, and emissions of greenhouse gases (nitrous oxide) (Boyandin et al., 2017). Commercially available CRFs apply a poorly biodegradable fossil-based polymer skin around a selected fertilizer pellet formulation as a diffusion membrane. ...
... To exploit the benefits of CRFs without spreading micro-plastic waste and in accordance with the EU Fertilizing Products Regulation (Regulation (EU) 2019/1009), PHAs as bio-based and biodegradable polymers are an alternative to achieve the CRF function. There are several reports on the feasibility of different formulations and methods using high purity commercially available pure culture derived PHAs in CRFs Volova et al., 2016;Boyandin et al., 2017). ...
Article
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Conversion of organic waste and wastewater to polyhydroxyalkanoates (PHAs) offers a potential to recover valuable resources from organic waste. Microbial community-based PHA production systems have been successfully applied in the last decade at lab- and pilot-scales, with a total of 19 pilot installations reported in the scientific literature. In this review, research at pilot-scale on microbial community-based PHA production is categorized and subsequently analyzed with focus on feedstocks, enrichment strategies, yields of PHA on substrate, biomass PHA content and polymer characterization. From this assessment, the challenges for further scaling-up of microbial community-based PHA production are identified.
... However, the excessive agrochemicals application can cause eutrophication and toxicity of water, groundwater and air pollution, soil quality degradation, and even climate change [2]. One alternative is the development of sustained-release systems combining fertilizers with substances that retard the release of nutrients [3]. ...
... Hence, cationic compounds tend to intercalate into the interlayer space of MMt to form a dispersing complex [18]. The mechanochemical intercalation of fertilizer compounds (such as KNO 3 and NPK) into clay lamella was demonstrated by a change on MMt interlayer spacing giving a slow-release pattern of nutrient [7,9]. ...
Article
We developed a novel enhanced efficiency fertilizer based on chitosan (Cs) and montmorillonite clay (MMt) microparticles to prolong the potassium nitrate release. Potassium nitrate-containing chitosan/montmorillonite microparticles were obtained by spray drying technique and sodium tripolyphosphate (1 and 5% of TPP) was used to crosslink the Cs to improve the release properties. The potassium release characteristics of the microparticles in water and soil were determined. We observed a decrease in the swelling ability of the chitosan for crosslinked microparticles with 5% of TPP by 52% and, consequently a reduction in the nutrient release. The kinetic release mechanism of potassium for non-crosslinked and crosslinked microparticles with 1% of TPP involved both intraparticle diffusion and surface diffusion, while the microparticles crosslinked with 5% of TPP was controlled by swelling. The microparticles were capable of maintaining higher concentrations of potassium in the soil during long periods (up to several weeks). The microparticles have great potential for applications in agriculture based on its release efficiency.
... Within this perspective, the use of biopolymers with thermoplastic characteristics has shown much potential. [8][9][10][11][12] Biodegradable thermoplastics, especially poly(hydroxyalkanoates) (PHAs), have emerged as major alternatives because they have good control of released compounds, complete biodegradation with biocompatible byproducts, and can be industrially obtained in large quantities by common processes. ...
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Here we investigate the behavior of controlled‐release systems based on poly(hydroxybutyrate) (PHB) to propose an actuation mechanism in a designed environment. Two formulations were produced employing 5% pure NPK fertilizer or 30% of bentonite nanoparticles (Bent) previously modified with NPK. The polymeric composites were obtained by melt processing and their thermal properties evaluated. The release of active compounds was evaluated by conductometric analysis in aqueous solutions at different pHs for 30 days, and the results were modulated by the Korsmeyer‐Peppas model. Also, the systems were evaluated for their biodegradation characteristics using different soil types to generate a decomposition profile. In general, the systems showed a good release control, with 40% and 50% of fertilizer being released in 30 days, depending on the conditions and type of polymeric composite employed. The model indicated a linear release of active compounds in the first 30 days, according to the Fick diffusion. Additionally, the compounds were relatively stable in the first 30 days when exposed to biodegradation, being degraded faster speed after this. The efficiency and applicability of the systems were confirmed by the germination tests, which showed that both systems containing NPK favored plant growth, while the system in which the active agents had been previously incorporated into nanoparticles provided a reduction in the waste of agrochemicals. Thus, a novel mechanism of action for polymeric controlled release systems based on thermoplastic biopolymers was determined, supporting more efficient industrial processes.
... Fertilizer is a necessary part of modern farming for improving crop production [1]. However, after being applied to the soils, a large amount nutrient was lost via volatilization and leaching, resulting in serious waste and environmental pollution [2,3]. ...
Article
Nitrogen fertilizer is one of the most vital major nutrients that plants need. However, its utilization rate was only 30% ~ 35%, and most of nitrogen was lost due to volatilization and leaching, which not only led to environmental pollution but also wasting of resources. Therefore, developing cost-effective, eco-friendly and multifunctional slow-release fertilizer (SRF) is still great challenging in agricultural production, and its carriers are very important. In this paper, a novel SRF was successfully prepared by eco-friendly inorganic/organic composites containing porous geopolymer and biocompatible polymers including starch (Sta) and polyvinyl alcohol (PVA). Firstly, the loess particle (Lo), a kind of widely distributed and eco-friendly cheap natural silicate, was used to synthesize porous loess-based geopolymer (Lo-GP). Secondly, using Lo-GP as carrier, Sta and PVA as gel coatings, and boric acid as a crosslinking agent, a novel multifunctional SRF ([email protected]/Gel) including nutrition elements of N, P and K fertilizer was prepared. Its structure and micromorphology were characterized by FT-IR, XRD, TG-DTG, BET, SEM, and EDS. [email protected]/Gel in the soil environment exhibited well water retention capacity, water absorbency in salt solutions, remediation of soil pH value, partly degradation in soil and promoting the growth of maize plants because of the organic-inorganic composites in [email protected]/Gel. The N nutrient slow-release longevity of [email protected]/Gel was more than 90 days and the cumulative release rate could be kept in 51.4%. It indicated that three-dimensional network and eco-friendly geopolymer with high porosity represent capacity for N fertilizer, as well as persistent slow-release performance. These results showed that geopolymer could be used as a carrier to load nutrients and the obtained [email protected]/Gel was a slow-release fertilizer with multifunctional performances.
... The advantage of such formulation systems is that the coated fertilizer is buried into the soil together with the plant seeds. Thus, the fertilizer has remained effective over a long period of time for plant growth (sometimes reach more than 2 months) (Boyandin et al. 2017). Although, the polymer coating systems of nitrate have effectively improved the utilization of nitrate fertilizers into soils. ...
Article
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The current study shows an advanced synesthetic technique of a nitrate-fertilizer with a controlled release behavior into different soils (normal and acidic agriculture soils solutions) at different climate temperatures. The environmentally friendly and the biocompatible layered double hydroxide (LDH) clay material was used as a host to accommodate the nitrate anion into its interlayer gallery by applying a reconstruction-incorporation technique (the memory effect property of LDH that allows calcined LDH to memorize its original structure). The prepared materials were characterized by different spectroscopic techniques including; X-ray powder spectroscopy, IR, SEM, TEM, and TGA analyses. A remarkable loading ratio of the nitrate anion fertilizer was recorded into the LDH structure. Around 90 wt% of the intercalated nitrate anion was released in a sustained controlled behavior over around 24 days, while the same amount of nitrate was released over 10 days in the acidic soil. Accordingly, the present study offers a new passway for the formulation of controlled release fertilizers by using the hosting anionic clay LDH materials.
... Quality is not tied to a specific polymer purity (or impurity), average molecular mass, melting point, crystallinity or even PHA type. These properties are inextricably linked to a spectrum of needs for a number of possibly meaningful PHA application areas [15,[145][146][147][148][149][150][151][152][153][154][155][156][157][158][159]. ...
... For PHA, some innovative niche applications have been explored already, such as bio-based paper coating (Lauzier et al., 1993), bio-based glue (Pereira et al., 2019), and slow-release fertilizer/herbicide (Boyandin et al., 2017;Cao et al., 2019) . However, none of these applications are well-established yet. ...
Article
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Polyhydroxyalkanoate (PHA) production is a promising opportunity to recover organic carbon from waste streams. However, widespread application of waste-derived PHA as biodegradable plastic is restricted by expensive purification steps, high quality requirements, and a fierce competition with the conventional plastic market. To overcome these challenges, we propose a new application for waste-derived PHA, using it as bacterial substrate in self-healing concrete. Self-healing concrete is an established technology developed to overcome the inevitable problem of crack formation in concrete structures, by incorporating a so-called bacteria-based healing agent. Currently, this technology is hampered by the cost involved in the preparation of this healing agent. This study provides a proof-of-concept for the use of waste-derived PHA as bacterial substrate in healing agent. The results show that a PHA-based healing agent, produced from PHA unsuitable for thermoplastic applications, can induce crack healing in concrete specimens, thereby reducing the water permeability of the cracks significantly compared to specimens without a healing agent. For the first time these two emerging fields of engineering, waste-derived PHA and self-healing concrete, both driven by the need for environmental sustainability, are successfully linked. We foresee that this new application will facilitate the implementation of waste-derived PHA technology, while simultaneously supplying circular and potentially more affordable raw materials for self-healing concrete.
... There are many studies on the effects of CRU application on cotton production worldwide [20][21][22] , but there is a lack of information about the application of CRU in combination with FA. Hence, the objective of this study was to investigate the effects of CRU combined with FA on (i) cotton yield and fiber quality; (ii) leaf senescence; (iii) soil inorganic nitrogen (NO 3 -N and NH 4 + -N) content; and (iv) nitrogen use efficiency. ...
Article
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A split-plot field experiment was conducted in 2018–2019 to study the effects of nitrogen fertilizer types and fulvic acid (FA) rates on soil nitrogen and cotton growth. The nitrogen fertilizers included controlled-release urea (CRU) and urea, which were applied combined with three FA rates (90, 180 and 270 kg ha-1). The main plot was the nitrogen fertilizer type, and the subplot was the FA rate. The results showed that the lint yield of the FA180 treatment was 5.2–8.6% higher than the FA90 and FA270 treatments. Moreover, moderate FA application markedly improved the cotton leaf SPAD value (chlorophyll relative value), photosynthesis and chlorophyll fluorescence parameters compared with low and high FA rates. Replacing urea with CRU significantly increased the soil inorganic nitrogen and nitrogen use efficiency and also improved cotton fiber quality parameters. Meanwhile, the boll weight and seed yield of the CRU treatments were 1.5–8.4% and 3.3–19.1% higher, respectively, than the urea treatments. The interaction between nitrogen type and FA rate had a positive effect on cotton growth. Thus, the application of CRU combined with 180 kg ha-1 FA on cotton can not only improve the fiber quality and delay leaf senescence but also increase the yield and economic benefit.
... Generally, PHAs are produced in microbial cultures which often use carbon-rich waste streams as feedstocks; therefore, PHAs produced in this way include more sustainable characters. Polymers of varying monomer compositions have been produced at pilot scales or larger to produce bioplastic raw materials for various used including medical, industrial, agricultural, packaging, cosmetic and household uses [18][19][20][21][22]. Polyhydroxy-alkanoates can be recovered and purified from their microbial hosts using a variety of methods [23,24]. ...
Article
Full-text available
Background and objective: Over 1 billion tons of foods are wasted every year (not consumed by humans or animals). Most of this waste ends up in landfills. As the global population increases, mankind must look for more sustainable means of living. A recently popular idea is the use of organic wastes as carbon feedstocks for fermentation that produces value added products. Polyhydroxyalkanoates are a family of bio-based, biodegradable polymers that can be produced in large quantities using food and food processing wastes as the main feedstocks. In many cases, biocatalysts have been engineered to efficiently use these waste compounds to produce large quantities of useful intracellular polyhydroxyalkanoates. Results and conclusion: In the current study, various polyhydroxyalkanoates were produced; each with different thermal and mechanical characteristics useful for different applications. If polyhydroxyalkanoate production facilities are established next to food waste accumulation sites (e.g., large landfills), potentials for the economical and sustainable polyhydroxyalkanoate production sound promising.
... More importantly, chemical hydrolysis for PHAs is slow; they are degraded by natural microflora via truly biological degradation to carbon dioxide and water or methane and water under aerobic and anaerobic conditions, respectively [19]. Consequently, the fully degradation process of PHAs takes several months in biological media, which makes it suitable to prepare prolonged-action or long-term formulations and particularly useful in agricultural applications, such as seed coatings, pesticides or fertilizers delivery [20][21][22]. Moreover, the advancement of PHAs biosynthesis technique has enabled the largescale industrial manufacture of these prospective polymers [23]. ...
... Coated substances are used for production of composite materials, [1] reagents with controlled release of the active component, [2] and slow release fertilizers. [3][4][5][6][7][8][9][10][11][12][13] Coating of plant seeds is used to protect them against negative environmental effects and to provide nutrients during germination. [14,15] In the food industry, the coating of bioactive components is used to regulate redox reactions, to adjust taste, color, and odor, to increase shelf life, etc. [16][17][18][19] Coating process is used also in the pharmaceutical industry for the production of drugs (tablets). ...
Article
In this study, a new model for the fluidized bed coating process is presented. The model allows to predict the degree of coverage of solid particles. Analytical solutions of model equations for batch apparatus and for continuous apparatus operated in the steady-state mode were obtained. An algorithm for the numerical solution of model equations for multistage apparatus was developed. To identify the parameters of the developed mathematical model and to verify its adequacy, a physical experiment was conducted on a laboratory scale installation. A comparison of calculated and experimental data was performed. Good agreement is observed between the modeling and the measurements.
... Then, the composite matrix was used to construct pressed 3D forms loaded with ammonium nitrate at 25% of the total mass of the formulation (Boyandin et al., 2017). ...
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The aim of this work was to obtain biodegradable polymeric systems based on poly(hydroxybutyrate) (PHB) for use in the controlled release of agrochemicals and to analyze the relationship between the properties of polymers and the rates of release of active compounds. Two types of systems were obtained: one using nitrogen, phosphorous, and potassium (NPK) fertilizer directly mixed within the polymer matrix and another with the fertilizer previously incorporated in bentonite (Bent) and mixed with the polymer. The systems were obtained by melt processing and then evaluated by their properties. The release of the active compounds was analyzed by conductometric analysis using an aqueous solution as release medium for 240 hours. The obtained results were correlated with the biodegradation process of PHB. All of the systems presented a significant reduction in the active compounds released to the environment as compared with the direct application of NPK. The PHB/NPK systems showed a release of up to 37% of the compounds, while the PHB/m‐Bent showed greater control, with a release between 4% and 11% after 240 hours. In addition, the properties of the polymer systems presented a direct relationship with the rate of active compounds released. The type of production process, properties, and biodegradability indicate interesting potential of these systems for application in the controlled release of active compounds.
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In the natural state, the concentration of carbon dioxide in the atmosphere is about 300 μmol mol–1. Plants need a suitable balance of CO2 to achieve optimal growth. The optimum CO2 content corresponding to a high photosynthesis rate is between 0.1 and 1.0% by volume. However, air has only a CO2 content of 0.03% by volume, so plants cannot use all of their growth potential. The use of fertilizer to assist in the supply of CO2 increases the rate of photosynthesis. In this work, a slow-release CO2 gas fertilizer inspired by polyphenol chemistry was prepared to provide sustainable CO2 that could improve plant photosynthetic capacity and get a higher crop yield. The core–shell structure was designed to confer gas fertilizers slow-release property. Micron-sized calcium carbonate particles with uniform particle size and regularity morphology, as carbon sources for plant photosynthesis, was a core, and tannic acid was coated on it as a shell via oxidative oligomerization and cross-linked by polyetherimide. The structure and morphology of fertilizers were characterized by scanning electron microscopy, X-ray energy dispersive spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. In vitro experiments, the prepared fertilizers were proved to have slow-release properties. And then through net photosynthesis rate, chlorophyll fluorescence parameters, chlorophyll content, leaf area, leaf mass per area, and dry matter to study the effects of slow-release CO2 gas fertilizers on plant physiology of Brassica chinensis. The results revealed that the slow-release CO2 gas fertilizers not only had good slow-release properties but also can well improve plant photosynthesis.
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In this work, cornstalk (CS) was irradiated by high energy electron beam to obtain honeycomb-like porous CS (PCS). The PCS was loaded with ammonium sulfite (AS) and then coated by polyvinyl alcohol (PVA)-Fe3O4 to obtain PCS-AS@PVA-Fe3O4. The PCS-AS@PVA-Fe3O4 could reduce hexavalent chromium (Cr(VI)) to trivalent chromium (Cr(III)) by SO32-, then the Cr(III) combined with PCS-AS@PVA-Fe3O4 through hydrogen bonds. The resulting PCS-AS@PVA-Fe3O4/Cr with a high magnetism could be conveniently separated from water via a magnet. PCS-AS@PVA-Fe3O4/Cr showed a high performance on controlling Cr(VI) migration in soil and uptake by plant. Meanwhile, ammonium could be released from PCS-AS@PVA-Fe3O4, favoring plant growth. Therefore, this work not only provides a promising and low-cost approach to remove Cr(VI) and promote plant growth simultaneously, but also provides a new route for CS recycling, which might have a potential application value.
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This study employed a novel and environment-friendly biopolymer/oxidant catalytic system, viz., poly(3-hydroxybutyrate)/peroxymonosulfate (PHB/PMS), for pretreating wastewater sludge for the first time. Under optimal conditions, i.e., 3.1 × 10⁻⁴ M of PMS and 3.3 g L⁻¹ of PHB at pH = 6.0, the PAHs in the sludge matrix was decreased by 79% in 12 h. Increase in salinity (75% synthetic seawater) achieved 83% of PAHs degradation. Functional groups (C=O) of the biopolymer matrix were active centers for biopolymer-mediated electron transfer that produced reactive oxygen species (SO4•−, HO•, and ¹O2) for adsorption and catalytic oxidation of PAHs in the sludge. Functional metagenomic analysis revealed the main genus, Conexibacter (phylum, Actinobacteria) exhibited PAH-degrading function with high efficiency in the biodegradation of PAHs from sludge pretreated with PHB/PMS. Coupling chemical oxidation and biostimulation using bacterial polymer-based biomaterials is effective and beneficial for pretreating wastewater sludge toward circular bioeconomy.
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Field trials on controlled release fertilizers (CRF) and a nitrification inhibitor (NI) were conducted in order to show their potential to increase N use efficiency (NUE) and to conserve air and water quality. For this purpose, flood irrigated barley grown on a clay soil (Colorado, USA), center-pivot irrigated potato grown in a sandy field (Colorado, USA), and corn grown on a loamy soil at a large scale lysimeter (Fukushima, Japan) were selected. NI (dicyandiamide) and CRF (polyolefin coated urea) were capable of reducing N2O emissions from urea applied to the barley field by 81 % and 35 %, respectively. Total N fertilizer losses averaged 15 and 10 % in the NI and urea treatments, respectively. On the other hand, those from the CRF treatment averaged only 1.9 %, indicating that CRF showed the highest potential to increase N use efficiency. The trials in the potato field demonstrated that CRF could markedly increase NUE and tuber yields. A single basal application of CRF at planting (N rate, 112 kg ha) produced tuber yields comparable with those of traditional fertilizer applications (112 kg N ha)by basal dressing, 90 kg N ha by topdressing and 67 kg N ha by 8 fertilizations). The urea and CRF plots in the corn fields showed similar N2O emission patterns, having two high emission periods following the basal and topdressed N applications in the urea plots and the enhanced N release from a short linear formulation and a long sigmoidal formulation in the CRF plots, respectively. However, the total N2O emission value of the CRF plots was almost one third of that of the urea plots. The plant recovery of CRF N was almost two times of that of urea N. Finally, the authors discussed that contributions of CRF and NI to conserve air and water quality are basically due to maximizing NUE and reducing the N fertilization rate.
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Particle coating is becoming increasingly important in fertilizer, pharmaceutical and food industries. The demand for coating granular fertilizers with minerals is increasing. Urea is coated with PhosphoGypsum, neem oil, polymeric suspensions and micronutrients like sulfer, zinc etc.Coating of PhosphoGypsum on urea fertilizer is a important application of coating process . Coating of urea particles is done to increase nitrogen use efficiency of urea. Nitrogen losses due to leaching, surface volatilization, and denitrification can be minimized by controlling the dissolution rate. Coating also helps to impart strength, increase in bulk density and lowering of caking tendency, thus improving the handling properties. The objective of present paper is to present the improvement in properties of urea obtained by fluidized bed coating of urea with Phosphogypsum using wet and dry methods.Emulsion of PhosphoGypsum, Neem (Azadirachta indica L.) oil, LAB (Linear Alkyl Benzene) and water was prepared in concentration s of 5%, 10% and 15%. Coating experiments were carried out with both PhosphoGypsum, Neem Oil, LAB and water (wet coating) and PhosphoGypsum, Neem Oil and LAB (dry coating) . PhosphoGypsum coated samples were analyzed for crushing strength, dissolution rate, dustiness factor and phosphogypsum content. Characterization of coated and uncoated urea prills is done to optimize and control the process of coating and also the performance of urea coating process can be checked which is useful for checking feasibility of this process on an industrial scale. The experimental results showed that wet method is better than dry method and 1.7 mm diameter size particle give better results than 1.4 mm size diameter particle. Dissolution rate, which is directly related to the nitrogen use efficiency is reduced as a result of coating, thus giving coated urea high moisture holding capacity.
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Current nitrogen (N) and potassium (K) fertilization involves the use of conventional fertilizer materials with little information on the use of slow release materials. The objectives of this research were to evaluate new programmed slow-release N and K fertilizers for cotton production. Field experiments were conducted in 1997 and 1998 in Tennessee and Arkansas in the USA. The applied nutrient rates were a percentage of the total recommended rates for each state. In 1997, the applied percentages were 100, 80, and 60%; an additional 40% rate was evaluated in 1998. The recommended rate of either N or K was applied as conventional fertilizers controls. These varying rates of programmed-release materials were applied in direct contact with the seed at planting while the conventional fertilizers were broadcast before planting. Cotton yields were not reduced when the N rate was reduced to 60% recommended rate and applied as Meister programmed slow-release N. Yields were reduced when N applications were further reduced to 40% the recommended rate in 1998. Similarly, in-furrow applications of the slow-release K at 60% of the recommended rate did not affect yields for both states. Our results indicate that programmed-release; soil-applied fertilizers can potentially provide a one-time fertilizer application at planting with no detrimental effect on seedling germination, growth or yield. Furthermore, nutrient efficiency for applying the slow-release materials was increased by maintaining high yields at reduced fertilizer rates.
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Controlled release fertilizer (CRF) hydrogels were prepared from poly(vinyl alcohol), poly(vinyl alcohol)/chitosan and chitosan using glutaraldehyde as a crosslinker. Intermolecular interactions of the CRF hydrogels were elucidated using FTIR. Water absorbency characteristics of the CRF hydrogels were also studied. It was found that the CRF hydrogels exhibited the equilibrium swelling ratio (SR) in the range 70–300%. The water retention of soil containing the CRF hydrogels was also examined. It was found that the CRF hydrogels increased the water retention of the soil. After 30days, soil containing the PVA-, PVA/CS- and CS-hydrogels showed the water retention capacities of 25%, 10% and 4%, respectively. While the soil without the CRF hydrogel had already given off most of the water. The release behavior of potassium from the CRF hydrogels, both in deionized water and in soil, was investigated. In soil, the potassium release mechanism from the PVA- and PVA/CS-hydrogels were non-Fickian diffusion. On the other hand, the CS hydrogel showed, n value that was close to 1.0 corresponding to case II transport. In deionized water, all the CRF hydrogels showed small values of release exponent (n < 0.5) indicating a quasi-Fickian diffusion mechanism. KeywordsControlled release-Hydrogel-Release kinetics-Swelling ratio-Water retention
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Experimental formulations of herbicide metribuzin embedded in matrices of degradable natural polymer poly(3-hydroxybutyrate) (P3HB) and its composites with polyethylene glycol (PEG), polycaprolactone (PCL), and wood powder have been prepared in the form of pressed pellets containing 75% of polymeric basis (pure P3HB or its composite with a second component at a ratio of 7:3) and 25% of metribuzin. Incubation of formulations in soil laboratory systems led to the degradation of the matrix and herbicide release. The most active release of metribuzin (about 60% of the embedded herbicide over 35 days) was detected for the P3HB/PEG carrier as compared with P3HB, P3HB/wood and P3HB/PCL forms (30-40%). Thus, the study shows that herbicide release can be controlled by the matrix formulation. Metribuzin formulations exerted a significant herbicidal effect on the plant Agrostis stolonifera, used as a weed plant model. Application of these long-term formulations will make it possible to reduce environmental release of chemicals, which will restrict the rate of their accumulation in trophic chains of ecosystems and abate their adverse effects on the biosphere.
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Background: Rising levels of mineral fertilizer use can lead to accumulation of fertilizers in soil, water and foodstuffs. One of the approaches to preventing these problems is to develop controlled release forms of fertilizers. Results: Experimental formulations of the nitrogen fertilizer urea loaded in degradable matrix of the natural polymer poly-3-hydroxybutyrate in the form of films, pellets and coated granules were constructed and investigated. Nitrogen release into soil occurred as the polymer was degraded, and it was dependent on the geometry of the carrier and the amount of nitrogen loaded in it, showing that nitrogen release can last for 30 days or longer and that release rates can be controlled by varying the fabrication technique employed. P3HB/urea formulations have a favorable effect on the soil microbial community. The use of embedded urea has a beneficial influence on the growth of the creeping bentgrass (Agrostis stolonifera) and lettuce (Latuca sativa) and reduces removal of nitrogen with drain water. Conclusion: The slow-release nitrogen formulations developed in this study can be buried in soil together with seeds preventing nitrogen deficiency. The use of such slow-release formulations can decrease the amounts of chemicals in the environment and prevent their adverse effects on the biosphere.
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Poorly drained claypan soils can increase the importance of tillage and N management for corn (Zea mays L.) production. Field research in 2008, 2009 and 2010 (high rainfall years) near Novelty, MO (40° 1' N, 92° 11' W) sought to determine the effect of polymer-coated urea (PCU) placement [strip-tillage (ST) deep banded and no-till (NT) broadcast] and application timing (fall, early preplant and preplant) on red clover (Trifolium pratense L.) biomass and corn response compared to non-coated urea (NCU) and anhydrous ammonia (AA) in the presence and absence of nitrapyrin a nitrification inhibitor. Strip-tillage reduced clover dry weights 20% in 2008 and 2009 and early preplant ST reduced dry weights 40 to 45% in 2010 compared to NT. Corn plant population was 8,100 to 8,400 plants ha -1 greater with ST compared to NT. Preplant applications of AA plus nitrapyrin, AA, ST placement of PCU and NCU increased grain yields 1 to 1.2 Mg ha -1 compared to fall applications of these fertilizer sources. Fall and preplant ST placement of PCU increased grain yields 1.2 Mg ha -1 compared to NCU. Strip-till placement of PCU and NCU increased yields 2.1 to 3.2 Mg ha -1 over broadcast applications of these fertilizer sources. Strip-till placement of PCU synergistically increased yield over NCU and broadcast applications of PCU or NCU due to increased stands and possibly due to better plant utilization of the banded N fertilizer utility.
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In spite of several published studies we have an incomplete understanding of the ion-release mechanisms and characteristics of polymer-coated fertilizers (PCF). Here we extend current conceptual models describing release mechanisms and describe the critical effects of substrate moisture and temperature on macro- and micronutrient release of three PCF types: Polyon®, Nutricote®, and Osmocote®. Nutrient release was quantified at weekly intervals for up to 300 d from 5°C to 40°C in water and chemically inert sand, substrates that allowed release quantification without confounding effects of ion sorption/desorption. At least two release-timeframe formulations of each PCF type were studied and all products had similar nutrient concentrations to allow isolation of the effect of coating technology. Contrary to several studies, our data and model indicate that there is no significant difference in nutrient-release rates in water and a moist, solid substrate. This means that release rates determined in water can be used to model bio-available nutrient concentrations in moist soil or soilless media where sorption/desorption properties alter concentrations after release. Across all PCF, the nutrients most affected by temperature were typically N, K, B, Cu, and Zn, while the least affected were P, Mg, and Fe. We also found consistent differences among the coating technologies. Osmocote fertilizers released faster than specified at both high and low temperatures. Nutricote had relatively steady release rates over time and a nonlinear response to temperature. Polyon released more slowly than specified but replicate samples were highly uniform.
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Controlled release urea (CRU) has been shown to improve nitrogen fertilizer use efficiency in a number of production systems. However, the effectiveness of CRU will be strongly affected by the environmental conditions of the region. Research trials were conducted at five locations across four major ecoregions spanning 1600 km across the Northern Great Plains and Pacific Maritimes of North America from 2004 to 2006 to evaluate the effects of a single application of polymer-coated urea (CRU) or split applications of urea fertilizer as compared with non-coated urea for their effects on crop growth, crop N concentration, and crop N accumulation of wheat (Triticum aestivum L.), barley (Hordeum vulagre L.) canola (Brassica napus L.) and corn (Zea mays L.) across a wide range of environmental conditions. Urea applied as an in-soil band at the time of seeding was generally as or more effective than similarly placed CRU, split application of urea or blended urea and CRU in the semi-arid Mixed Grassland, moist Aspen Parkland or wet Boreal Transition ecoregions in increasing early season dry matter yield and seed or grain yield of canola, wheat or barley. Similarly, broadcast urea was as or more effective than broadcast CRU, split applications or blended applications in increasing corn dry matter yield under the wet conditions in the Lower Mainland ecoregion. There were some situations where use of split applications or use of the CRU in a blend with the non-coated urea resulted in increases in grain yield as compared to the non-coated urea, primarily under moist conditions in the Boreal Transition or Aspen Parkland ecoregions. Some yield losses occurred from use of the CRU as compared with the non-coated urea and were attributed to delays in release of N from the granule that limited early season N availability and crop growth, especially in corn with a high N demand. Effects on grain N concentration and accumulation of N in the crop at harvest were mixed, with the CRU, blended applications of CRU and urea or split applications occasionally producing higher grain N concentration and N accumulation in the crop than the non-coated urea. Benefits of CRU on grain N concentration were more frequent than benefits on grain yield, but were not large or consistent. Response of crop growth and N uptake to N management was generally similar under CT and RT, with occasional differences occurring due to changes in yield potential or N deficit associated with the differences in tillage management. Therefore, under growing conditions across a wide range of ecoregions in the Northern Great Plains and the Pacific Maritimes, the use of CRU or split applications do not appear to provide a consistent improvement in crop yield, N concentration in the grain, total N accumulation at harvest, or nitrogen use efficiency as compared to standard regional timing and placement of non-coated urea.
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Fertilizers contain essential nutrients for agricultural growth and development. However, most nitrogen fertilizers are substances with high solubility of ions and are very susceptible to leaching and volatilization. In order to minimize these losses, an alternative is the creation of a physical barrier around granules. One way is to coat granules with polymers. In the present work urea granules were coated with polyhydroxybutyrate and ethyl cellulose in varying conditions in presence of emulsifiers. The original granules and the final products were characterized by Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy and Thermogravimetry in order to evaluate the surface morphology, the interaction between the granules and the coating and the rates of mass change. The rates of urea release in distilled water were measured with a commercial enzyme kit. It is shown that those polymers are effective for coating of granules, leading to reduction of rates of urea dissolution in water.
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Spray coating of polymer latex onto fertilizer particles in a fluidized bed for producing controlled-release urea is an environment friendly technology as it does not need any toxic organic solvent. Since the spray coating process in a fluidized bed occurs in the presence of particle collisions, the coating of the particles is random, intermittent and multiple, thus making it difficult to investigate the film formation process. In this paper, an experimental model apparatus was designed and used to investigate the effects of the key factors in the spray coating process. This apparatus reasonably simplified the complex process to avoid particle collisions and randomness in the coating. The intermittent coating in the fluidized bed was modeled by periodic coating and dewatering in the experimental apparatus. A large area film was obtained, and the film permeability was measured. The effects of atomizing gas flow rate, spray rate of latex, solid content of latex and gas temperature on film structure and film permeability were investigated. It was found that water transfer played a dominant role in the spray coating process.
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The weekly nitrogen (N), phosphorus (P), and potassium (K) release from 17 polymer‐coated controlled‐release fertilizer (CRF) formulations of Nutricote, Apex Gold, Osmocote, and a 9‐month Macrocote were measured at 30.6±0.8°C and 40.0±1.5°C. Five grams of each CRF were placed at a depth of 50 mm in 280x50 mm acid washed then rinsed silica sand columns which were leached with deionized water three times each week until nutrient recovery ceased. The volume of leachate was recorded each week and subsampled for ammonium‐N, nitrate‐N, phosphate‐P, and K analyses. Each CRF treatment was replicated three times at each temperature. Nutrient release profiles were determined. Longevities, measured as weeks to 90% nutrient recovery, were considerably shorter than the nominated release periods for all formulations. Within each CRF product group, the longevity of 9 and 12 month formulations were similar with Apex Gold 12–14 month high nitrate having the longest (38 weeks for N at 30°C) and Osmocote 8–9 month the shortest (23 weeks for N at 30°C). There were consistent trends in the nutrient release periods across all CRFs with P>K>N and with differences of around 10% in duration between nutrients. The P:N release ratio exceeded 0.10 for most CRFs during the early release period indicating an adequate P supply for most plant species. The mean reduction in longevity for Nutricote, Apex Gold, and Osmocote formulations for an increase in incubation temperature from 30°C to 40°C was 19–21 % for N, 13–14% for P, and 14–15% for K. All CRFs released nutrients unevenly with the highest rate occurring during the early part of the release period. This pattern was accentuated at 40°C and by the shorter term release formulations. The nutrient release rates of all CRFs declined steadily after their maxima.
Article
Polymer-coated urea (PCU) has great potential for increasing crops production, enhancing the nitrogen (N) fertilizer use efficiency, and benefiting the ecosystem. However, current PCUs are used only in a limited market, and the main obstacle to the wider use of PCUs is high cost compared to conventional N fertilizers. In this study, the low cost PCU and large tablet polymer-coated urea (LTPCU) were prepared by using the recycling polystyrene foam and various sealants as the coating materials. The structural and chemical characteristics of the coating shells of the coated fertilizers were examined. The N release characteristics of coated fertilizers were determined in 25℃ water under laboratory condition. The relationship between the N release longevity and the amount of coating material and the percentage of different sealants were evaluated. The results indicated that recycling polystyrene foam was the ideal coating material of the controlled release fertilizer. The polyurethane which was synthesized by the reaction of castor oil and isocyanate was better than the wax as the additive to delay the N release rate of coated urea. The coating material used for LTPCU was 70-80% less than those used for commercial PCUs under the same N release longevity. The cost of the recycling polystyrene foam used for coating one ton pure N of the LTPCU was about one-seventh to one-eighth of the traditional polymer used for the commercial PCU. The experimental data showed that the LTPCU with good controlled-release capacities, being economical and eco-friendly, could be promising for wide use in agriculture and horticulture.
Article
The effectiveness of two polyolefin coated products, ‘Meister 70’ and ‘Meister 270’, as slow-release sources of nitrogen (N) for irrigated cotton, and uncoated calcium carbide as a source of acetylene to inhibit nitrification of urea-N and reduce losses by denitrification were studied. The crop was grown on a grey clay in the Namoi Valley of north western New South Wales. The fertilisers were applied at 50 and 150kgN/ha, combined factorialy with two application times, either pre- or post-sowing. Meister 270 did not release N fast enough to supply the plant’s requirements, and is not recommended as a source of N for cotton. Meister 70 was worthy of further study as a pre-sowing source of N because it maintained a higher concentration of ammonium in the soil for longer than urea, resulted in lower soil nitrate concentrations at all times, and increased the apparent recovery efficiency of fertilizer N. The uncoated calcium carbide was not as effective as the wax-coated material tested in previous studies.
Article
The present study describes the preparation and characterization of a novel urea slow-release nanocomposite, based on urea intercalation into montmorillonite clay by an extrusion process at room temperature. Nanocomposites with urea contents ranging from 50 to 80 wt % were successfully produced and characterized. Analyses by XRD, DTA, and SEM-EDX confirmed the effectiveness of this simple process to exfoliate the clay lamellae into the urea matrix, forming a product that can be classified as a nanocomposite, due to the exfoliation degree attained. Diametral compression tests showed that the samples were very deformable, and the release rate of active components in water showed that the nanocomposite showed a slow release behavior for urea dissolution, even in low montmorillonite amounts (20% in weight).
Article
This paper presented a new approach for preparing a new type of slow-release membrane-encapsulated urea fertilizer with starch-g-PLLA as biodegradable carrier materials. By solution-casting and washing rapidly with water the urea was individually encapsulated within the starch matrix modified by l-lactide through in situ graft-copolymerization. The release behavior of urea encapsulated in the films was studied, and following conclusions were achieved: (1) the introduction of hydrophobic PLLA reduced the swellability of starch matrix and decreased the release rate of urea; (2) the urea release rate could be controlled from several hours to 1 day by adjusting the graft efficiency; (3) scanning electron microscopy revealed that the urea encapsulated within the starch matrix was uniformly dispersed in the form of tiny cell and the urea encapsulated in the modified starch film released through a diffusion mechanism. Therefore, the modified starch products for controlled release could be expected to have widely potential application in agriculture industry as fertilizer carrier.
Article
To sustain the further world population, more fertilizers are required, which may become an environmental hazard, unless adequate technical and socioeconomic impacts are addressed. In the current study, slow-release formulations of nitrogen fertilizer were developed on the basis of natural attapulgite (APT) clay, ethylcellulose (EC) film, and sodium carboxymethylcellulose/hydroxyethylcellulose (CMC/HEC) hydrogel. The structural and chemical characteristics of the product were examined. The release profiles of urea, ammonium sulfate, and ammonium chloride as nitrogen fertilizer substrates were determined in soil. To further compare the release profiles of nitrogen from different fertilizer substrates, a mathematical model for nutrient release from the coated fertilizer was applied to calculate the diffusion coefficient D. The influence of the product on water-holding and water-retention capacities of soil was determined. The experimental data indicated that the product can effectively reduce nutrient loss, improve use efficiency of water, and prolong irrigation cycles in drought-prone environments.
Article
The microbial polyesters known as polyhydroxyalkanoates (PHAs) positively impact global climate change scenarios by reducing the amount of non-degradable plastic used. A wide variety of different monomer compositions of PHAs has been described, as well as their future prospects for applications where high biodegradability or biocompatibility is required. PHAs can be produced from renewable raw materials and are degraded naturally by microorganisms that enable carbon dioxide and organic compound recycling in the ecosystem, providing a buffer to climate change. This review summarizes recent research on PHAs and addresses the opportunities as well as challenges for their place in the global market.
Article
High N fertilizer and irrigation amounts applied to potato (Solanum tuberosum L.) on coarse-textured soils often result in nitrate (NO3) leaching and low recovery of applied fertilizer N. This 3-yr study compared the effects of two rates (140 and 280 kg N ha(-1)) of a single polyolefin-coated urea (PCU) application versus split applications of urea on 'Russet Burbank' potato yield and on NO3 leaching and N recovery efficiency (RE) on a loamy sand. Standard irrigation was applied in all years and excessive irrigation was used in another experiment in the third year. At the recommended rate of 280 kg N ha(-1), NO3 leaching during the growing season was 34 to 49% lower with PCU than three applications of urea. Under standard irrigation in the third year, leaching from five applications of urea (280 kg N ha(-1)) was 38% higher than PCU. Under leaching conditions in the first year (> or = 25 mm drainage water in at least one 24-h period) and excessive irrigation in the third year, PCU at 280 kg N ha(-1) improved total and marketable tuber yields by 12 to 19% compared with three applications of urea. Fertilizer N RE estimated by the difference and 15N isotope methods at the 280 kg N ha(-1) rate was, on average, higher with PCU (mean 50%) than urea (mean 43%). Fertilizer N RE values estimated by the isotope method (mean 51%) were greater than those estimated by the difference method (mean 47%). Results from this study indicate that PCU can reduce leaching and improve N recovery and tuber yield during seasons with high leaching.
Article
A double-coated, slow-release, and water-retention urea fertilizer (DSWU) was prepared by cross-linked poly(acrylic acid)-containing urea (PAAU) (the outer coating), polystyrene (PS) (the inner coating), and urea granule (the core). Elemental analysis results showed that the nitrogen content of the product was 33.6 wt %. The outer coating (PAAU) regulated the nitrogen release rate and protected the inner coating from damage. The slow-release property of the product was investigated in water and in soil. The possible mechanism of nitrogen release was proposed. The influences of PS coating percentage, temperature, water absorbency, and pH on the release of nitrogen were also investigated. It was found that PS coating percentage, temperature, and water absorbency had a significant influence on the release of nitrogen. However, the pH had no effect. The water-retention property of the product was also investigated. The results showed that the product not only had a good slow-release property but also excellent water-retention capacity, which could effectively improve the utilization of fertilizer and water resources. The results of the present work indicated that the DSWU would find good application in agriculture and horticulture, especially in drought-prone areas where the availability of water is insufficient.
Article
The commercial granular fertilizer NPK6-20-30 was coated using polysulfone (PSF), polyacrylonitrile (PAN), and cellulose acetate (CA). The coatings were formed from the polymer solutions by the phase inversion technique. Measurements of the thickness and porosity of the prepared coatings and a microphotographic observation of the coatings were performed. The physical properties of the coatings influence the release rate of macronutrients which are present in the core of the coated fertilizer. In the case of PAN coating with 60.45% porosity, prepared from a 16% polymer solution, 100% of NH(4)(+) and P(2)O(5) was released after 4 h of test and 99.7% of K(+) after 5 h of test, whereas in the case of coating with 48.8% porosity, 31.8% of NH(4)(+), 16.7% of P(2)O(5), and 11.6% of K(+) was released after 5 h. In all experiments, different selectivities of the coatings in terms of the release of components were observed. The release of potassium through the coatings made of PSF and PAN was the slowest. The same tendency was observed for the release of nitrogen through a coating of CA. The release of fertilizer active components was the slowest in the case of PSF. The lowest porosity coating was prepared from the 18% PSF solution.
  • J Love
  • J A Bryant
  • Eds
  • Wiley-Blackwell
Love, J., Bryant, J. A., Eds.; Wiley-Blackwell: Chichester, UK, 2017; p 147. Journal of Agricultural and Food Chemistry Article DOI: 10.1021/acs.jafc.7b01217
The effect of chitosan content to physical and degradation properties of biodegradable urea fertilizer
  • N N A Hamid
  • N Mohamad
  • L Y Hing
  • M F Dimin
  • M A Azam
  • M H C Hassan
  • M K S M Ahmad
  • A Shaaban
Hamid, N. N. A.; Mohamad, N.; Hing, L. Y.; Dimin, M. F.; Azam, M. A.; Hassan, M. H. C.; Ahmad, M. K. S. M.; Shaaban, A. The effect of chitosan content to physical and degradation properties of biodegradable urea fertilizer. J. Sci. Inno. Res. 2013, 2, 893−902.
Testing kinetic of nutrients release from complex mineral fertilizers coated with co-polyester films from pet waste recycling and effect on soil chemical properties
  • A Anghel
  • A.-R Lacatusu
  • R Lacatusu
  • S Iancu
  • M Lungu
  • R Lazaȓ
  • A Vrînceanu
  • C Balaceanu
Anghel, A.; Lacatusu, A.-R.; Lacatusu, R.; Iancu, S.; Lungu, M.; Lazaȓ, R.; Vrînceanu, A.; Balaceanu, C. Testing kinetic of nutrients release from complex mineral fertilizers coated with co-polyester films from pet waste recycling and effect on soil chemical properties. Scientific Papers. Series A. Agronomy. 2012, 55, 13−18.
Pshenitsa myagkaya yarovaya (Triticum aestivum L.), sort ALTAISKAYA 70 (Soft spring wheat (Triticum aestivum L.), cultivar ALTAISKAYA 70). Patent of the Russian Federation for selection invention No. 4758 of 25.05
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  • N V Peshkova
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  • V S Valekzhanin
  • E V Kvasnik
Korobeinikov, N. I.; Peshkova, N. V.; Boradulina, V. A.; Musalitin, G. M.; Valekzhanin, V. S.; Kvasnik, E. V. Pshenitsa myagkaya yarovaya (Triticum aestivum L.), sort ALTAISKAYA 70 (Soft spring wheat (Triticum aestivum L.), cultivar ALTAISKAYA 70). Patent of the Russian Federation for selection invention No. 4758 of 25.05.2009, 2009. http://reestr.gossort.com/reg/cultivar/10443 (in Russian).
The Use of Cyanobacteria for Biofuel Production
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  • C J Howe
Lea-Smith, D. J.; Howe, C. J. The Use of Cyanobacteria for Biofuel Production. In Biofuels and Bioenergy;
Pshenitsa myagkaya yarovaya ( L.), sort ALTAISKAYA 70 (Soft spring wheat ( L.), cultivar ALTAISKAYA 70).Patent of the Russian Federation for selection invention No. 4758 of 25.05
  • N I Korobeinikov
  • N V Peshkova
  • V A Boradulina
  • G M Musalitin
  • V S Valekzhanin
  • E V Kvasnik