Effect of organic and chemical fertilization on the onion crop (Allium cepa L.)

The bulb onion (Allium cepa L.) is a vegetable widely cultivated and in high demand in national and international markets. Due to the risks that the indiscriminate use of agrochemicals represents for human health and the environment, the present study aimed to make a comparative analysis of the effects of organic vs chemical fertilization currently used in the cropping of red hybrid bulb onion (Eureka). Three organic fertilizers (Zumsil®, ComCat® and EcoFungi®) were compared to three chemical fertilizers (15-15-15®, Muriate of Potash® and Nitrofoska®). The response variables were: plant height at 30 and 60 days after transplanting (DAT), length, diameter and average weight of bulbs, yield in tons per hectare and the relationship between height at 30 and 60 DAT. The experiment was carried out under a completely randomized design with four replicates, seven treatments and 28 experimental units. The statistics used include an analysis of variance and a Canonical Biplot that allowed to obtain groups of variables and to determine their correlation with each one of the treatments. Additionally, a marginal analysis of dominant treatments was performed. Positive response of variables was strongly associated with organic fertilizers. From the economic point of view, the ComCat® organic fertilizer represented an ecological alternative with excellent benefits for the producer. This research is in line with the trends for agrochemical-free foods