Nitrogen fertilisation in tropical pastures: what are the impacts of this practice?

Abstract

It is estimated that approximately 47% of the world’s ruminant meat and milk is produced in tropical and subtropical regions, with pasture comprising the main food base of these animals. Nitrogen fertilisation is an essential practice for the maintenance of pasture productivity, considering that a deficiency of this nutrient is a primary factor in triggering pasture degradation. In addition to directly influencing the photochemical and biochemical phases of photosynthesis, nitrogen stimulates enzyme activity and the synthesis of enzymes responsible for fixing CO2 (Rubisco in C3 plants and phosphoenolpyruvate carboxylase in C4 plants), thus increasing the efficiency of atmospheric CO2 capture. All of these physiological processes are easily observed macroscopically in the characteristics of forage plants. This review examines the impact of nitrogen fertilisation in tropical pastures on the main components of production systems (soil, plants and animals), describes the results obtained in different situations and highlights the most efficient ways of producing meat without environmental impacts.

Optimum nitrogen fertilization rate and nitrogen use efficiency forBrachiariahybrid andMegathyrsus maximusvaries with stage of regrowth

“…13 However, reports on optimum N fertilizer rates for tropical grass forages are extremely limited and is heavily dependent on the soil characteristics at the specific site. Nitrogen fertilization allows for rapid N mineralization, providing optimum soil conditions that facilitate greater uptake of N into plant tissues, 28 resulting in higher CP content in forage. The linear response observed in this study implies that further increase in forage CP content may be possible with higher N rates.…”

Defoliation management and nitrogen fertiliser rate affect canopy structural traits of grazed guineagrass (Megathyrsus maximus) cv. Zuri under rotational stocking

“…2019). In tropical and subtropical pasture ecosystems, N is the most limiting nutrient for forage production (Gurgel et al . 2020; Silveira and Kohmann 2020).…”

Biological and economic responses to increasing nitrogen rates in Mombaça guinea grass pastures

“…In Cerrado regions of Brazil, it is estimated that there are at least 32 million ha of degraded pastures 1 , i.e., areas characterized by a decrease in regrowth vigor, consequently reducing carrying capacity and animal production, which results in great economic and environmental damages. Nitrogen fertilization is essential for maintaining pasture productivity and for its sustainability, since nitrogen deficiency is one of the main factors triggering pasture degradation process 2 , 3 .…”