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Forage legumes in grass pastures in tropical Brazil and likely impacts on greenhouse gas emissions: A review
Author(s) -
Boddey Robert M.,
Casagrande Daniel Rume,
Homem Bruno G. C.,
Alves Bruno J. R.
Publication year - 2020
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/gfs.12498
Subject(s) - brachiaria , agronomy , grazing , forage , greenhouse gas , legume , monoculture , methane emissions , biology , environmental science , livestock , fodder , tropics , agroforestry , ecology
Beef cattle producers seldom use fertilizers for their pastures in tropical regions of Brazil. Slowly, this is changing but because of the need for repeated applications, N fertilizer is rarely applied. The introduction of a forage legume is an appropriate solution for this problem, but until recently adoption has been very low as the legumes generally have not persisted in the sward. We report research on how grazing management can affect the persistence of stoloniferous legumes in pastures of Brachiaria spp. and the problems of establishing and maintaining crown‐forming legumes such as Stylosanthes spp. With suitable management, milk or bovine carcass yields can be equal or greater from mixed than from grass‐alone pastures fertilized with 120 or 150 kg Nha ‐1 year −1 . In addition to savings in CO 2 emissions from fossil fuels for the production and distribution of N fertilizers, nitrous oxide emissions from cattle excreta and legume residues are lower than those from N‐fertilized brachiaria grass monocultures. Other studies indicate that enteric methane emissions from cattle may be mitigated when forage legumes are included in their diet. The use of forage legumes in mixed pastures for tropical regions is emerging as a feasible strategy to keep meat and milk production at acceptable levels with reduced greenhouse gas emission rates.