ISSN:
1573-0867
Keywords:
Zinc fertilizer
;
controlled-release
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01049580
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