Nitrogen fertilization is one of the management techniques necessary to achieve high yield potential in irrigated agricultural systems. The objective of this study was to evaluate effects of nitrogen applied as topdressing on phytobiomass and nutrient use efficiency in dry bean cultivar BRS Horizonte. The experiment was conducted at the National Rice and Beans Research Center of Embrapa in a Distrophic Red Latosol in randomized block design with four replications. The nitrogen rates used were 0, 30, 60, 120 and 240 kg ha-1, half applied 10 days after plant emergence and half, 17 days after plant emergence in the form of urea. Dry bean phytobiomass was linearly related with N rate at flowering, while at harvest the response was quadratic. Relation between grain harvest index, nitrogen harvest index and N rate was quadratic and the maximum index was obtained at 140 kg N ha-1. Nitrogen use efficiency by dry bean varied with N rate applied and type of efficiency while agronomical and physiological efficiencies decreased with increase N rates.
Phaseolus vulgaris; dry matter; agronomic efficiency; physiological efficiency
