Onion is a highly consumed vegetable whose production is based on smallholder agriculture. The onion production is responsible for the generation of jobs and income for many farmers who have this as the only source of income. There is a growing demand for onion production technologies suitable for smallholders, with emphasis on agroecology. In this respect, we highlight the use of mulches and organic fertilizers. The aim of this study was to evaluate the effect of different mulches, associated to increasing doses of castor bean cake applied in side dressing on total production and diameter of onion bulbs grown in organic system. There was a significant effect of the mulch over the total yield and the yield obtained of different diameter classes of bulbs. There were no significant effects of side dressing with the castor bean cake, neither of the interaction between the mulch and the fertilization with castor bean cake. The beneficial effect of mulch which probably had more influence on the increasing of onion yield was the maintenance of moisture and reduction of soil temperature range.
Allium cepa; mulch; organic manuring