Abstract
Thermoplastic matrix controlled-release (C.R.) zinc fertilizers are produced by extruding a mixture of zinc salt and inert polymer material. Three methods of laboratory evaluation were used to characterize a range of C.R. zinc formulations differing in concentration and nature of zinc salt, carrier matrix, and size. The methods were (i) electron microscopy, (ii) zinc emission into water, and (iii) zinc diffusion in indicator-agar. These methods complemented each other, with electron microscopy elucidating physical features governing zinc release from the fertilizer pellets. Finely divided particles of soluble zinc salt, for instance, were associated with formulations whose release characteristics approached theoretical (time)0.5 -order release kinetics. Apart from zinc particle size, other factors controlling zinc emission characteristics were the type of zinc salt, the zinc loading, and pellet size. Varying the polymer matrix materials had little or no effect on zinc release from the C.R. zinc formulations compared in this study.
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References
Billmeyer FW (1971) Textbook of polymer science. 2nd edition. New York, London, Sydney: John Wiley and Sons, Inc
Blanchar RW and Caldwell AC (1966a) Phosphate-ammonium-moisture relationships in soils. I. Ion concentrations in static fertilizer zones and effects on plants. Soil Sci Soc Am Proc 30: 39–43
Blanchar RW and Caldwell AC (1966b) Phosphate-ammonium-moisture relationships in soils. II. Ion concentrations in leached fertilizer zones and effects on plants. Soil Sci Soc Am Proc 30: 43–48
Cardarelli NF (1976) Controlled-release pesticide formulations. Boca Raton, Florida: CRC Press, Inc
Cardarelli NF (1978) Controlled-release trace nutrients. In 5th Int Symp on Controlled Release of Bioactive Materials, Proc., pp 9.1–9.10. Akron, Ohio: The University of Akron
Cardarelli NF (1980) Monolith polymer devices. In Kydonieus AF Ed. Controlled-release technologies: Methods, theory and applications, Vol. I, pp 56–71. Boca Raton, Florida: CRC Press, Inc
Hauck RD and Koshino M (1971). Slow-release and amended fertilizers. In Olson, RA editor-in-chief Fertilizer technology and use, pp 455–94. Madison, Wisconsin: Soil Sci Soc Am Inc
Joyce DC, Bell LC, Edwards DG and Asher CJ. Thermoplastic matrix controlled-release zinc fertilizers. II. Effect of soil and formulation characteristics on zinc emission. Fert Res (submitted for publication)
Joyce DC, Edwards DG, Asher CJ and Bell LC. Thermoplastic matrix controlled-release zinc fertilizer. III. Zinc nutrition of linseed on a sand and a clay. Fert Res (submitted for publication)
Kydonieus AF Ed. (1980a) Controlled-release technologies: Methods, theory and applications, Vol. I. Boca Raton, Florida: CRC Press, Inc
Kydonieus AF Ed. (1980b) Controlled-release technologies: Methods, theory and applications, Vol. II. Boca Raton, Florida: CRC Press, Inc
Kydonieus AF (1980c) Fundamental concepts of controlled-release. In Kydonieus AF Ed. Controlled-release technologies: Methods, theory and applications, Vol. II. pp 1–19. Boca Raton, Florida: CRC Press, Inc
Kydonieus AF and Berosa M Eds. (1982) Insect supression with controlled-release pheromone system. Vol. I. Boca Raton, Florida: CRC Press, Inc
Maynard DN and Lorenz OA (1979) Controlled-release fertilizers for horticultural crops. Hort Rev 1: 79–140
Olson RA Editor-in-chief (1971) Fertilizer technology and use. 2nd edition. Madison, Wisconsin: Soil Sci Soc Am Inc
Parsons R (1959) Handbook of electrochemical constants. London: Butterworths Scientific Publications
Scher HB Ed. (1977) Controlled-release pesticides. ACS Symp Series 53. Washington, D: Am Chemical Soc
Tanquary AD and Lacey RE Eds (1974) Controlled-release of biologically active agents. Advances in Experimental Medicine and Biology Series 47. New york, London: Plenum Press
Tisdale SL and Nelson WL (1975). Soil fertility and fertilizers. 3rd edition. New York: MacMillan Publishing Co., Inc
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Joyce, D.C., Bell, L.C., Asher, C.J. et al. Thermoplastic matrix controlled-release zinc fertilizers. Fertilizer Research 17, 235–250 (1988). https://doi.org/10.1007/BF01049580
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DOI: https://doi.org/10.1007/BF01049580