Modeling Controlled Nutrient Release from a Population of Polymer Coated Fertilizers:  Statistically Based Model for Diffusion Release

Shaviv, A.; Raban, Smadar; Zaidel, Elina

doi:10.1021/es0205277

Cited by 67 publications

(60 citation statements)

References 5 publications

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“…The reduced effectiveness of CRU to reduce seedling damage in that study was related to differences in release characteristics measured in water at 23ºC: 40 to 50% of total N was released within 10 d for CRU used in 1999 and 2000, compared with 10 to 15% released within 10 d for CRU used in this study. The effectiveness of polymer coatings depends on coating thickness, polymer permeability and variability in coating thickness and granule radii (Shaviv et al 2003). Effectiveness may also be reduced by damage from handling and application equipment (Parish 2001).…”

Section: Discussionmentioning

confidence: 99%

Controlled-release urea for winter wheat in southern Alberta

McKenzie¹,

Bremer²,

Middleton³

et al. 2007

Can. J. Soil. Sci.

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. Controlled-release urea for winter wheat in southern Alberta. Can. J. Soil Sci. 87: 85-91. The recent development of low-cost controlled-release urea (CRU) may provide additional options for N fertilization of winter wheat (Triticum aestivum L.). Two field experiments were conducted over 3 yr at three locations in southern Alberta to evaluate different options of applying CRU to winter wheat. In the first experiment, three N fertilizers (20-day CRU, 40-day CRU and urea) were seed-placed and side-banded at the time of seeding at 0, 30, 60, 90 and 120 kg N ha -1 . Stand densities were substantially reduced by seedrow application of urea at rates greater than 30 kg N ha -1 , but were unaffected by seedrow application of CRU, even at the highest rate of N application. When N fertilizer was side-banded, stand densities were unaffected by fertilizer type or N rate. Yield gains due to N application were reduced by application of high rates of seed-placed urea, but similar for other treatments. Grain protein concentration and N uptake were also similar for CRU and seed-placed urea. In the second experiment, three N fertilizers (CRU, urea and ammonium nitrate) were broadcast at 30 kg N ha -1 in early spring on plots that had received 0, 30 or 60 kg N ha -1 of CRU at the time of seeding. Inadequate release of spring broadcast CRU was indicated by reduced grain protein concentrations relative to conventional N fertilizers. Under the conditions experienced in our study, CRU substantially increased the maximum safe rate of seed-placed urea, provided minimal benefits to N response relative to side-banded urea, and was less effective than conventional N fertilizers when broadcast in early spring. . Trois années durant, les auteurs ont effectué deux expériences sur le terrain à trois endroits du sud de l'Alberta afin d'évaluer les diverses possibilités de bonification du blé d'hiver avec de l'ULL. Pour la première expérience, ils ont appliqué trois engrais N (ULL 20 jours, ULL 40 jours et urée) avec la semence ou en bande latérale au moment des semis à raison de 0, 30, 60, 90 ou 120 kg de N par hectare. L'application d'urée aux lignes de semis à un taux de plus de 30 kg de N par hectare diminue sensiblement la densité du peuplement, mais cela n'est pas le cas quand on utilise de l'ULL, même aux taux les plus élevés. Quand l'engrais N est appliqué en bande latérale, le type d'engrais et le taux d'application n'affectent pas la densité du peuplement. L'application d'une quantité élevée d'urée avec la semence réduit les gains de rendement associés à l'application d'un engrais N, mais les autres traitements donnent des gains analogues. L'ULL et l'application d'urée avec la semence donnent aussi une concentration de protéines dans le grain et un taux d'absorption du N similaires. Lors de la deuxième expérience, les auteurs ont appliqué trois engrais N (ULL, urée et nitrate d'ammonium) à la volée à raison de 30 kg de N par hectare au début du printemps sur des parcelles bonifiées avec 0, 30 ou 60 kg de N par hectare sous forme d'UL...

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Section: Discussionmentioning

confidence: 99%

Controlled-release urea for winter wheat in southern Alberta

McKenzie¹,

Bremer²,

Middleton³

et al. 2007

Can. J. Soil. Sci.

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“…This, of course, assumes that the coating is applied evenly around the granule and does not fail (e.g., crack) at any point in the process. Attention to coating thickness, its solute permeability, granule properties, such as density and solubility, and the variance of these properties across the entire applied population can allow for better control of timing and rate of P release when applying these products (Shaviv et al, 2003a, 2003b). …”

Section: Slow Releasersmentioning

confidence: 99%

A Review of the Latest in Phosphorus Fertilizer Technology: Possibilities and Pragmatism

2019

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The development of highly concentrated phosphorus (P) fertilizers, such as triple superphosphate, by the Tennessee Valley Authority helped mark the beginning of a revolution in the way we manage food crop nutrition. Since then, scientists, with the help of farmers, have made great advancements in the understanding of P fate and transport across many environments but largely have failed to produce a new generation of products and/or application techniques that are widely accepted and that vastly improve plant acquisition efficiency. Under certain conditions, important advancements have been made. For example, applying liquid formulations of phosphates in lieu of dry granules in some highly calcareous soils has dramatically reduced precipitation as sparingly soluble calcium phosphate minerals, but other attempts, such as the co‐application of humic substances, sorption to layered double hydroxides, or use of nanoparticles, have not generated the kind of results necessary to continue economically increasing crop yields without further environmental cost. New sources of fertility will need to be affordable to produce, transport, and furnish P to soil solution in a manner well synchronized with crop demand. This paper provides a review of recent literature on cutting‐edge phosphorus fertilizer technology. The goal is that this synthesis will be used as a starting point from which a larger discussion on responsible nutrient management and increased P use efficiency research can be built. Core Ideas Reaction with some soil constituents limits P availability and crop yield. A variety of approaches to improve fertilizer use efficiency are being explored. Ideally, P availability should be well synchronized to crop demand. More innovation along with mechanistic and field‐scale trials is required.

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“…In this case, the methylcellulose dissolves out of the film leaving small channels in the film through which drug can diffuse. The ethyl cellulose barrier left on the particle serves as restraining barrier to maintain constant diffusion area and constant diffusion path length [29][30][31][32].…”

Section: Models Based On Diffusionmentioning

confidence: 99%

“…With coated products, one can obtain pulsed dosing effects i.e., repeat action, by merely employing a small number of different thickness coated particles, or obtaining the more common sustained effect by utilizing a spectrum of different thickness coatings. Some granules within each group release the drug at intervals overlapping other groups, resulting in a smooth rather than discontinuous release, profile [29][30][31][32].…”

Section: Models Based On Dissolutionmentioning

confidence: 99%

Microparticles Formulation as a Targeting Drug Delivery System

Abdellatif¹

2017

JNMR

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A great interest has been centered on the idea of replacing daily administration of a drug with delivery devices which release a constant effective dose to the target tissues via a controlled release mechanism. Many pharmaceutical investigations have been carried out to develop controlled release oral dosage forms that sustain drug release. A sustained release system is defined as one in which the drug is initially made available to the body in an amount sufficient to give a rapid onset of the desired therapeutic response, after which the level of the therapeutic concentration is maintained constant for the desired duration of time. This review discusses the formulation of sustained release drugs by different kinds of microparticles as a targeting tool for new drug delivery.

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Modeling Controlled Nutrient Release from a Population of Polymer Coated Fertilizers: Statistically Based Model for Diffusion Release

Cited by 67 publications

References 5 publications

Controlled-release urea for winter wheat in southern Alberta

Controlled-release urea for winter wheat in southern Alberta

A Review of the Latest in Phosphorus Fertilizer Technology: Possibilities and Pragmatism

Microparticles Formulation as a Targeting Drug Delivery System

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