Structural and Production Characteristics of Piatã Grass Forage Submitted to Levels of Nitrogen

Abstract

Piatã grass (Brachiaria brizantha cv. Piatã) is a tropical grass cultivating in pasture production system. The aim of this study was to evaluate the effects of nitrogen levels (0, 125, 250, 375 and 500 kg•N•ha −1) on structural characteristics and forage production of Piatã grass. The experiment comprised of twenty grass parcels arranged in randomised completely casualties design. This study was carried out between November of 2007 and April of 2008, with 175 experimental days. A quadratic effect (P < 0.05) was verified for nitrogen dosage on canopy height, final leaf blade length and leaf area index. Nitrogen fertilisation altered the population density of tillers, with estimated maximum value of 955 tillers•m −2 at a nitrogen dose of 357 kg•ha −1. A quadratic effect (P < 0.05) was also verified for nitrogen levels on the production of total and green leaf blade dry matter, with estimated maximum values of 19,253 and 11,548 kg•ha −1 •year −1 for nitrogen levels of 411 and 384 kg•ha −1 , respectively. However, a considerable portion of forage production obtained by nitrogen addition occurred from stem production. The productions of green leaf blade dry matter, tiller density, leaf blade length and leaf blade index are all variables related to structural aspects and pasture quality, with all attaining their highest values at a mean nitrogen application level of 380 kg•ha −1 .

Acumulación de forraje de pasto buffel e híbridos de Urochloa a diferente edad de rebrote

“…La capacidad productiva de cualquier especie forrajera se determina por su composición genética (Miles 2006), edad de la planta, condiciones climáticas presentes a través del año (Lara et al 2010, Garay et al 2017b) y manejo agronómico (Cruz-Hernández et al 2017), los cuales modican las características morfológicas y estructurales de la planta (Dourado et al 2015). Se ha mencionado que el conocimiento de la inuencia de la estacionalidad en el crecimiento y producción de forraje en las especies de interés para una determinada región es importante, ya que permite conocer el tiempo de mayor y menor disponibilidad de forraje y adoptar estrategias de manejo para maximizar la producción animal; por ello, se debe evaluar el efecto estacional y la dinámica de crecimiento de nuevos cultivares de gramíneas forrajeras para optimizar su aprovechamiento (Avellaneda et al 2008).…”

Optimum harvest time for Kikuyu grass (Cenchrus clandestinus) according to the number of leaves per tiller and nitrogen fertilization

“…The increase of N fertilization has been related to a higher foliar elongation (Borrajo and Alonso, Da Silva et al, 2012;Almeida et al, 2011). Therefore, nitrogen deficiency may be related to the slow elongation of Kikuyu pastures observed in low fertility soil used in this experiment, and greater height of the pasture in response to N. Previous studies also had reported N fertilization has a positive effect on tilling (Dourado et al, 2015, Da Silva et al, 2012. This effect may be greater in plants that grow distant from each other than in dense stoloniferous growth species such as Kikuyu.…”

Organic Reserves in ropical Grasses under Grazing

“…When nitrogen availability in the soil is not limiting for the plant, the minimum percentage of nitrogen required to reach the maximum growth rate appears to decrease regularly as the plant grows [26]. This results in a decrease of N content per unit of leaf area as the leaves are progressively shaded, due to LAI development [27] [28].…”