Impact of nitrogen fertilization on guinea grass (Panicum maximum, Jacq) in the humid premountain forest in the Department of Tolima.

Abstract

P?ginas 17-21El objetivo del trabajo de investigaci?n fue evaluar la respuesta de diferentes dosis (0, 100, 150 y 300 kg/ha) de nitr?geno en la producci?n de pasto guinea (Panicum maximum, Jacq). Los resultados servir?n para establecer una recomendaci?n t?cnico-econ?mica viable de fertilizaci?n para la producci?n de esta gram?nea bajo condiciones de bosque h?medo sub-andino. El dise?o experimental utilizado fue bloques completos al azar con las cuatro dosis de nitr?geno mencionadas. Se aplic? 246 y 60 kg ha/a?o de CaCO3 y K2 O, respectivamente para correcci?n del pH. La producci?n y el porcentaje de materia seca en el forraje fueron medidos en los tres cortes realizados a intervalos de 28 d?as. Los cortes presentaron efecto significativo (P<0,01) en la producci?n y porcentaje de materia seca. La mayor producci?n de materia seca se encontr? en el corte dos (56 d?as) con 0,23 kg/m2 y el m?ximo porcentaje de MS se encontr? en el corte tres (84 d?as) con 21,4%; mientras que la fertilizaci?n de 300 kg N/ha/a?o present? el mayor rendimiento productivo de la gram?nea. La mayor rentabilidad financiera fue encontrada en el testigo (0 kg N/ha/a?o).ABSTRACT. The goal of this study was to evaluate different levels of nitrogen fertilization (0, 100, 150 and 300 kg/ha/year) on the production of Guinea grass (Panicum maximum). The results should support a viable technical-economical recommendation of fertilization for the production of this grass under sub-Andean humid forest conditions. An experimental design of randomized blocks was used, with four treatments of nitrogen fertilization. It was also applied to all plots 246 and 60 kg/ha/yearof CaCO3 and K2O as pH corrective inputs. The production and percentage of dry mater were evaluated in all three cuttings, which were carried out every 28 days. The cutting presented a significant effect (P<0.01) in the production and percentage of dry matter. The highest dry matter production was found in the second cutting (56 days) with 0.23 kg/m2; and the highest dry matter percentage was found in the third cutting (84 days) with 21%; whereas, the fertilization with 300kg N/ha/year showed the highest grass productivity. The greatest financial profitability was found in the control treatment (0 kg N/ha/year)