Description
Nitrogen is the nutrient that most contributes to increase forage productivity and quality. The objective was to evaluate Brauna brachiaria (Urochloa brizantha cv. Brauna) submitted to nitrogen doses in the Brazilian savannah through the total and green mass production, leaf:stem and brachiaria:weed ratio. Plots were established in a randomized block design, with four replications and four N doses 0, 50, 100 and 150 kg N/ha). After the uniformization cut, the data collect cycles occurred when the canopy reached 30 cm average height. Samples were taken until 15 cm from the ground in an area of 0.25 m2 . Fractions were separated according botanical (brachiaria and weeds) and morphological (leaf, stem, dead material and inflorescence) components. The maximum and minimum response points were calculated by derivative. Samples were weighed and dried and values were used to calculate components mass production and ratios. The highest value of dry matter production occurred at 100 kg N/ha dose (2,606 kg DM/ha). Below or above this value the mass production decreased. The highest value of relation green mass:dead material was 4.24 at 131 kg N/ha dose. Brauna was able to control the weeds, and the best performance (4.68) was observed at 86 kg N/ha dose. The highest accumulation rate occurred at 87.5 kg N/ha dose. Brauna had higher leaf:stem ratio with higher nitrogen doses but above 131 kg N/ha the dead mass can result in energy loss per respiration. Above 86 kg/N the mass accumulation rate decreases which means that the fertilization cost is not favorable over this dose.
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Mass Production and Morphology of Brauna Brachiaria Under Different Nitrogen Rates in the Brazilian Savannah
Nitrogen is the nutrient that most contributes to increase forage productivity and quality. The objective was to evaluate Brauna brachiaria (Urochloa brizantha cv. Brauna) submitted to nitrogen doses in the Brazilian savannah through the total and green mass production, leaf:stem and brachiaria:weed ratio. Plots were established in a randomized block design, with four replications and four N doses 0, 50, 100 and 150 kg N/ha). After the uniformization cut, the data collect cycles occurred when the canopy reached 30 cm average height. Samples were taken until 15 cm from the ground in an area of 0.25 m2 . Fractions were separated according botanical (brachiaria and weeds) and morphological (leaf, stem, dead material and inflorescence) components. The maximum and minimum response points were calculated by derivative. Samples were weighed and dried and values were used to calculate components mass production and ratios. The highest value of dry matter production occurred at 100 kg N/ha dose (2,606 kg DM/ha). Below or above this value the mass production decreased. The highest value of relation green mass:dead material was 4.24 at 131 kg N/ha dose. Brauna was able to control the weeds, and the best performance (4.68) was observed at 86 kg N/ha dose. The highest accumulation rate occurred at 87.5 kg N/ha dose. Brauna had higher leaf:stem ratio with higher nitrogen doses but above 131 kg N/ha the dead mass can result in energy loss per respiration. Above 86 kg/N the mass accumulation rate decreases which means that the fertilization cost is not favorable over this dose.
