RESUMO Determinar o acúmulo e a exportação de nitrogênio (N) pelo feijoeiro em função da palhada e do seu parcelamento é importante visando o manejo e a sustentabilidade dos sistemas agrícolas. O objetivo com esse trabalho foi determinar o acúmulo e a exportação de N pelo feijoeiro cultivado sob palhada de milho ( Zea mays) e braquiária (Urochloa ruziziensis) exclusivos ou em consórcio e em função do parcelamento da adubação nitrogenada em cobertura. O experimento foi conduzido em Jaboticabal-SP-Brasil, durante a safra 2012/13, num Latossolo Vermelho eutrófico típico, sob área irrigada no sistema plantio direto. O delineamento experimental foi em blocos ao acaso com parcelas subdivididas com quatro repetições, totalizando 120 subparcelas dimensionadas em 25m2 cada. As parcelas foram constituídas pelos sistemas de cultivo antecessores ao feijoeiro: milho, milho consorciado com braquiária e braquiária. As subparcelas foram compostas por dez parcelamentos da adubação nitrogenada de cobertura (PN) estádios fenológicos V 3, V4 e R5 em diferentes combinações. A produtividade de grãos do feijoeiro difere entre os sistemas de cultivo e em função do parcelamento do N em cobertura. O cultivo exclusivo de braquiária proporciona maiores acúmulos de N na parte aérea do feijoeiro comparado ao milho e seu consórcio com braquiária. Independentemente do sistema de cultivo, a aplicação de N em cobertura em dose única de 90 kg ha-1 em V4 (terceiro trifólio) proporciona acúmulos e exportações semelhantes àqueles na ausência da adubação nitrogenada. Os parcelamentos com aplicação de N em cobertura no estádio R5 (pré-florescimento) incrementa as exportações desse nutriente no feijoeiro em sucessão ao milho e seu consórcio com braquiária. | ABSTRACT Determining nitrogen (N) accumulation and export by common bean as a function of straw and of the splitting of this nutrient is very important, aiming at the management and sustainability of agricultural systems. This study aimed to determine the N accumulation and export by common bean as a function of Zea mays and Urochloa ruziziensis grass straw (maize, maize/U. ruziziensis intercropping and U. ruziziensis) and splitting of top-dressing N fertilization. The experiment was conducted in Jaboticabal-SP-Brazil, during the 2012/13 crop season, in a Red Eutrophic Oxisol (Eutrudox) in no-tillage under irrigation. The experimental design was a randomized block with split plots with four replicates, totaling 120 subplots sized in 25m2 each. The plots consisted of the cropping systems prior to common bean: maize, maize/ U. ruziziensis intercropping and U. ruziziensis. The subplots were composed of ten top-dressing N fertilization splitting schemes (NS) at the phenological stages V3, V4 and R5 in different combinations. Common bean grain yield differs among cropping systems and as a function of top-dressed N split application. U. ruziziensis grass as single crop promotes greater N accumulation in common bean shoots compared to maize and its intercropping with U. ruziziensis grass. Regardless the cropping system, top-dressing N application in a single dose (90 kg ha-1) at V4 leads to similar accumulations and exports to those found in the absence of N fertilization. Splitting schemes with N application at the R5 stage increase the exports of this nutrient by common bean in succession to maize and its intercropping with U. ruziziensis grass.

ABSTRACT The use of filler liming in the sowing furrow can improve the chemical characteristics of the soil and, together with nitrogen fertilization, increase common bean yield. The objective of this study was to determine the effect of filler liming of the sowing furrow along with nitrogen topdressing fertilization on the yield of common bean, cultivar Pérola, irrigated by central pivot, in the Cerrado Region. The field experiments were conducted for three consecutive cropping years, in a randomized block design with four replications, in a 2x4 factorial scheme, consisting of two doses of nitrogen topdressing fertilization (zero and 60 kg ha-1 of N) and four doses of filler liming application in the sowing furrow (0, 200, 400 and 600 kg ha-1 of CaCO3). The plant density (PD), number of pods (NP), number of grains (NG), mass of 100 grains (M100) and, grain yield (GY) were evaluated. The use of 60 kg ha-1 of N provided greater M100 and GY. The increase of the filler liming doses in the sowing furrow led to a reduction of the NP. The filler liming dose of 200 kg ha-1 provided higher values of NG and M100, and when combined with the nitrogen topdressing fertilization, improved the GY of the common bean.

ABSTRACT The common bean exhibits wide genetic variability for technological quality traits, mineral concentrations, and bioactive compounds. For this reason, investigating the correlations between those traits in common bean lines of different gene pools contributes to the progress of biofortification programs. In the present study, two recombinant inbred line populations of Mesoamerican and Andean common bean were evaluated at the F5:7 generation. Technological quality was evaluated based on mass of 100 grains and seed coat color, which was determined using a colorimeter that analyzed the L* (white to black), a* (green to red) and b* (blue to yellow) values. The concentration of six minerals and bioactive compounds (phytates and phenolic compounds) was evaluated and used to characterize the nutritional composition of the lines. The evaluated common bean lines differed (p ≤ 0.05) for all technological quality traits, mineral concentrations, and bioactive compounds, except for the zinc concentration in Andean beans. Seed coat color (L*, a*, and b* values) was highly correlated with most of the evaluated minerals and with the phytates in Mesoamerican beans. In Andean beans, seed coat color (L*, a*, and b* values) was correlated with the concentrations of potassium, magnesium, iron, and phenolic compounds. The nutritional composition of common bean lines of different classes is variable: black beans have higher concentrations of potassium, phosphorus, calcium, zinc, and phytates; carioca beans stand out with high magnesium concentration; and cranberry beans have higher concentrations of potassium, magnesium, and iron.