Nitrogen fertilisation as a strategy for intensifying production and improving the quality of Massai grass grown in a humid tropical climate

Abstract

The use of nitrogen fertilizers intensifies forage production, especially in tropical climates. This study aimed to evaluate the effects of nitrogen fertilization on the quantitative and qualitative characteristics of Massai grass grown in a humid tropical climate, specifically Am-type. A completely randomized design was used with six treatments and five replicates. The treatments used were a control treatment (without nitrogen application) and five doses of nitrogen fertilization (100, 200, 300, 400, and 500 kg N ha⁻¹year⁻¹). Urea was used as the nitrogen fertilizer for six applications, with an interval of 30 days. The leaf elongation rate increased by 69.1% at a dose of 500 kg N ha⁻¹ compared to that of the control. The leaf appearance rate and green leaves per tiller increased with nitrogen fertilization. Nitrogen fertilization did not affect the percentage of leaf blades and dead tissue. The average height of the canopies was 44.0 cm, regardless of fertilization. There was a quadratic response in total forage accumulation (TFA), with a maximum of 19,136 kg dry matter at a dose of 391 kg N ha⁻¹year⁻¹. Nitrogen utilization efficiency was the same as that of TFA. There was a reduction in the recovery of applied nitrogen and the agronomic efficiency of applied nitrogen with nitrogen fertilization. The number of cuts increased linearly with nitrogen fertilization, from 3.2 to 7.5 cuts. Crude protein content increased with nitrogen fertilization. Therefore, nitrogen fertilization favored the productivity and quality of Massai grass grown in a humid tropical climate.

Keywords:

• fodder
• forage accumulation
• leaf appearance rate
• Megathyrsus maximus × M. infestus
• nitrogen
• sheet

Acknowledgments

The authors thank the undergraduate and graduate students from the Group on Ruminants and Forage Production of the Amazon (GERFAM) for their help in conducting the research.

Disclosure statement

No conflict of interest was reported by the authors.

Additional information

Funding

This study was financed in part by the Federal Rural University of Amazon and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brazil (CAPES) Finance Code 001 (Procad nr. 71/2013).