Effect of nitrogen application rate on yield, forage quality, and animal performance in a tropical pasture

Abstract

A three-year-long field experiment was conducted in a continuous grazing system with a variable stocking rate to evaluate effects of increasing nitrogen levels in Marandu grass ( Brachiaria brizantha Hochst ex A. Rich Stapf “marandu”) on herbage mass, forage accumulation rate (FAR), forage quality, stocking rate (SR), average daily gain (ADG), gain per hectare (GPH), and gain per kg of applied N. The experimental design was completely randomized with four treatments (control without application of N, and 90, 180, and 270 kg N ha −1 year −1 ) and three replicates (paddocks per treatment); nitrogen was applied in the form of urea. Herbage mass, crude protein (CP), FAR, SR, GPH, and the nitrogen nutrition index increased with increasing nitrogen level (P < 0.05), whereas the neutral detergent fibre (NDF), acid detergent fibre, and nitrogen usage efficiency decreased with increasing nitrogen level (P < 0.01). Crude protein was higher than 12% and NDF lower than 60% in all treatments. Nitrogen application rate affected ADG (P < 0.05) but did not fit any equation. The highest ADG was 90 kg N ha −1 year −1 (985 g animal −1 day −1 ). Increasing the nitrogen level is a promising way to improve Marandu grass production, nutritive value, and animal production.

Grazing Intensity Impacts on Herbage Mass, Sward Structure, Greenhouse Gas Emissions, and Animal Performance: Analysis of Brachiaria Pastureland

“…The observed mean CP and NDF contents found in this study varied from 14.0% to 14.7% and from 57.8% to 59.6%, respectively (Table 3). These values differed from several previous studies that used Marandu grass [10,26,27], but were in line with a study from Vietnam [28]. In the Brazilian studies, CP varied from 10% to 12% during the rainy season (November to April), and from 6% to 8% during the dry season, whereas NDF was always above 60%.…”

“…According to several studies, the Marandu palisade grass sward heights used in rotational grazing are 30 cm to put the animals and 15 cm to remove the animals [7][8][9][10]. These studies revealed that nutritive value decreases above 30 cm, and regrowth declines below 15 cm.…”

“…These studies revealed that nutritive value decreases above 30 cm, and regrowth declines below 15 cm. Usually, the adoption of pasture height that represents 95% of light interception results in a greater green leaf proportion, CP, lesser dead material, and neutral detergent fiber (NDF) during the growing season [10]. Pasture height also affects grazing behavior [2].…”

Crescimento e nutrição da Urochloa brizantha cv. Marandu inoculada com bactéria promotora de crescimento vegetal e sob diferentes doses de nitrogênio

“…A produção forrageira aliada à fertilização por nitrogênio aumentam o vigor e a produtividade do recrescimento (Delevatti et al, 2019) em contraste, o uso de inoculantes bacterianos para fornecer N e para promover um melhor crescimento da planta é uma opção para reduzir dano ambiental como a poluição das águas subterrâneas e emissão de gases de efeito estufa (Souza & Ferreira, 2017). Nesse contexto, o objetivo deste estudo foi avaliar a massa seca de parte aérea (MSPA), massa seca de raiz (MSR), massa seca total (MST), número de perfilho (NP), índice de clorofila (IC), comprimento da parte aérea (CPA) e nitrogênio foliar (NPA) de U. brizantha em decorrência da inoculação com Azospirillum brasilense associado com adubação nitrogenada, visando à redução dos custos da formação de pastagem e redução do período de estabelecimento da cultivar na área.…”

Nitrogen requirement of Brachiaria hybrid cv. Ipyporã

“…The correct fertilization management in pasture soils aims to provide adequate nutritional support for forage plants, which reduces degradation processes and consequently the costs of recovering degraded areas. Thus, fertilization has a marked effect on pasture, which improves the gain per hectare (DELEVATTI et al, 2019) and, especially, its persistence, even for species adapted to low soil fertility (MOREIRA et al, 2011).…”