GB1315396A - Coated granular fertilizers - Google Patents

Abstract

1315396 Cellulose-acetate-coated fertilizers IMMOBILIARE SETTE SRL 22 Sept 1970 [29 Sept 1969 26 Nov 1969] 45026/70 Heading C1B A fertilizer with a matrix in granular form, e.g. a matrix of polystyrene or pumice granules, is coated with a film of cellulose acetate which is capable of being decomposed on contact with the soil owing to autogenous physical and biochemical reactions, so as to perform a progressive fertilization of the soil. In particular, the trace element boron may be supplied by this method, e.g. by applying solutions of sodium tetraborate (Na 2 B 4 O 7 .10H 2 O) to the matrix or by grinding boron-containing glass to a powder, preferably of grain size 10 to 100 mÁ, to provide the matrix. A process for the production of such fertilizers comprises dipping grains of broken or ground matrix materials of a size about 3 mm. into a solution containing various fertilizer substances, e.g. substances which contain nitrogen, phosporus, potassium, trace elements, phyto-hormones and/or fungicides or weed killers. Waste waters may be used provided these contain sufficient materials of fertilizing value. The matrix grains impregnated with fertilizer substances are dried at a temperature such as to avoid the decomposition of organic substances present in them, e.g. phytohormones. The film material may then be sprayed on to the grains. The grains may be coloured by impregnating the fertilizer solutions with various pigments so that different fertilizers may be recognized.