The objective of this study was to validate the potential of four biofertilizing alternatives for onion bulb production in Cucaita, Boyaca, Colom- bia. The treatments evaluated were: 1) bocashi-hen manure, super broth 4, and fertilizer, 2) bocashi-cow manure, super broth 4, and fertilizer, 3) bocashi-hen manure, super broth 4, rhizosphere broth, and fer- tilizer, 4) bocashi-cow manure, super broth 4, rhizo- sphere broth, and fertilizer, 5) chemical control, and 6) absolute control. The experimental design was a random complete block with six treatments and four replications. The variables determined were: 'disease incidence', 'bulb number', 'disease unaffected bulb weight', 'disease affected bulb weight', 'total bulb weight', and 'bulb diameter'. The results indicated that the bocashis as well as the super 4 and rhizosphere broth contributed to the soil with a great amount and diversity of beneficial microorganisms, which were important for the equilibrium in plant nutrition and plant defence against pathogens. The lowest disease incidence was obtained in the treatments bocashi-hen manure, super broth 4, fertilizer and bocashi-cow manure, super broth 4, rhizosphere broth, fertilizer. In relation to the production variables, though none of the biofertilizing alternatives resulted significantly different to the chemical control, those which include Bocashi, super broth 4, rhizosphere broth, and an ad- equate rate of chemical fertilizer are considered the most promissory because in addition to produce re- sults similar to those obtained with the conventional technique of the farmer since the beginning they have a microbiological and chemical potential which is es- sential for the sustainability of the production and the environmental quality in the future.