Onion yield under agroecological farming system using distinct irrigation depths and soil covers
Agricultura orgânica, Allium cepa L, eficiência do uso da água
ABSTRACT: The present study was carried out in order to evaluate the effects of irrigation depths applied through drip and presence/absence of soil cover in onion yield, under agroecological farming. The experiment was conducted in Seropédica, RJ, Brazil, from May to September 2012. The experimental design was a randomized complete block with split-plot design with 10 treatments and 7 replications, characterized by the presence (+S) and absence (-S) of soil cover and five irrigation depths according to percentages of the crop evapotranspiration (ETc): 0, 22, 45, 75 and 100% (0, 155, 220.6, 320.5 and 372,7mm in +S condition and 0, 145.5, 207.6, 285, 351,4mm in -S condition). The irrigation influenced by second-order polynomial regression the total yield of bulbs, percentage distribution of bulbs in diameter classes and water use efficiency (WUE) in the -S condition, and in the linear regression the WUE in +S condition. The soil cover promoted an increase on the total bulb yield, WUE and the percentage of bulbs classified in classes of greater diameter.
José Guilherme Marinho Guerra, Eduardo Castro Ribeiro, Daniel Fonseca de Carvalho, Lucas Antonio de Freitas Santos