NOVELTY - Producing an organic fertilizer (A) comprises accelerated composting of sugar cane wastes in combination with vinasse and other organic wastes from food processing.    USE - (A) is used as organic fertilizer and soil conditioner; it provides both plant nutrients and activators of soil microorganisms (claimed); it may also be useful as food for plankton, in shrimp farming.    ADVANTAGE - (A) has excellent physicochemical and microbial properties, and can increase yields of crops by up to 10%.    DETAILED DESCRIPTION - Producing an organic fertilizer (A) comprises:    (a) accelerated composting of 'cachaza' (mixture of sugar cane fibers with coagulated colloids such as wax, albumenoids, calcium phosphate and soil particles) by filling into furrows (1 m depth per 3 m base), and optionally covering, depending on the time of year;    (b) after 1 week, inoculation with 4-6 l per tonne of a mixture of 33-67vol.% vinasse, aerobic sludge from processing of food plants, yeast sludge and water;    (c) after no more than a week, aeration of the mixture by mechanical turning, to promote aerobic fermentation of sugars, starch and lignin;    (d) during the second week, inoculating the mixture with 5-7 l/tonne of the mixture specified in (b), aerating again, and repeating this cycle at least 3 times until a product of 30-50wt.% moisture content is obtained;    (e) in a thermophilic phase, a top layer of powdered phosphate rock is applied, so that this reacts with ammonia and, in a subsequent series of reactions, forms diammonium phosphate, which becomes incorporated directly into the final product;    (f) optionally, in the maturation and cooling stages, the material is inoculated with mycelium of Aspergillus sp.,    (g) the product is crushed, passed to a vibratory sieve, then sieved material is milled to powder and transported to a granulator to form agglomerates with vinasse or molasses of 30-60degrees Brix, used at 2.5-8% on the powder; and    (h) the granules are passed to a rotating drier (parallel or countercurrent flow), where the drying gas has inlet and outlet temperatures 280 and 100degreesC and the product has inlet and outlet temperatures 35 and at most 140degreesC.    An INDEPENDENT CLAIM is also included for an organic fertilizer, prepared using the above method and having a moisture content of 18-22% when granular or 20-37% when powdered.