Rendimento e qualidade nutricional do grão de milho em função da adubação orgânica

Abstract

The objective of this study was to study the effect of green manure and organic compost on yield and nutritional quality of corn grain. The research was conducted at the Federal Rural University of Pernambuco / Garanhuns Academic Unit, in the agricultural year 2017, in the municipality of Garanhuns – PE. The experimental design was completely randomized, in a factorial scheme (3 x 4) + 2, with three replications. The treatments consisted of three leguminous plants (sunn hemp, cowpea beans and dwarf pigeon pea), four doses of organic compound (0, 20, 40 and 60 Mg ha-1), and two additional controls (absolute and mineral fertilization). The analyzed variables were: plant height, stalk diameter, number of leaves, number of spikes; length and spike diameter, number of grains per row, row number of grains, mass of 1000 grains, harvest index, grain N content and accumulation, N content in soil, grain yield; protein content and yield, ethereal extract, mineral material, total carbohydrates and energetic value of the grain. The data were submitted to analysis of variance, and the means of the treatments involving the legumes were compared by the Tukey's test (p <0.05). Concerning the study of organic compound concentrations, polynomial regression analysis was used. For the comparison of organic fertilization with the additional control and mineral treatments, the Dunnett test (p <0.05) was used. The green manure cowpea fertilizer provides increased components of maize production. The green manuring with cowpea associated to the doses of organic compound (40 and 60 Mg ha-1) conditions grain yield similar to the treatment with mineral fertilization. The cowpea beans associated with the highest dose of compound (60 Mg ha-1) favors the quality and protein yield of the corn grain superior to the mineral treatment. Cowpea green manure, associated with the 40 and 60 Mg ha-1 doses of compound, conditions similar values in the yield of oil, mineral material and total carbohydrates in relation to the mineral treatment. The green manuring with cowpea associated to doses 20, 40 and 60 Mg ha-1 of compound promotes similar response in the total carbohydrate content in relation to the chemical treatment. The cowpea beans associated with the 40 and 60 Mg ha-1 doses of organic compost condition similar to the treatment with mineral fertilization in the value and energy yield, being able to substitute it without compromising the nutritional quality of the grain.