PRODUTIVIDADE DE VARIEDADES DE MILHO NOS SISTEMAS DE CULTIVO ORGÂNICO E CONVENCIONAL

Abstract

This study was conducted to evaluate the yield of two maize varieties cropped with organic and mineral fertilizations either associated or unassociated. The randomized experimental design was used under a factorial scheme 2 x 3 x 2, with four replicates. The first factor corresponds to two maize varieties (Nitrodent and Nitroflint), whereas the second one represents three levels of mineral fertilization: without mineral fertilizer; 300 kg/ha of 4-14-8 + 100 kg/ha ammonium sulfate (S.A.); and 600 kg/ha of 4-14-8 + 200 kg/ha S.A. The third factor represents two organic fertilization levels: without organic fertilizer; and 40 m3/ha organic compound. The experimental plot consisted of eight plant rows with 8m length each one and 1m spacing from each others, so totaling 64 m2 area. The yield of the maize grains by plot were evaluated, and the data were subjected to variance analysis (test ¿ 5%). The averages were compared by Tukey test at 5% probability level. Both varieties Nitrodent and Nitroflint only cropped under the organic system reached more than 6.500 kg/ha. The exclusive organic cropping system provided higher yields of maize grains, compared to the conventional system. No significant differences were found between the exclusive organic system and the combination of both organic and conventional systems upon the grain yield of the Nitrodent variety.