IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
capítulos de libros
Título:
Grazing impacts on soil physical, chemical and ecological properties in forage production systems
Autor/es:
TABOADA, M.A.; RUBIO, G.; CHANETON, E.J.
Libro:
Soil management: building a stable base for agriculture
Editorial:
American Society of Agronomy & Soil Science Society of America
Referencias:
Lugar: Madison; Año: 2010; p. 301 - 320
Resumen:
Extensive systems of animal husbandry (e.g. meat and dairy cattle, sheep, goats, and so on) are mainly based on the direct grazing of grasslands, pastures, fodder crops, and crop residues by livestock. Grazing effects on soil properties of forage production systems follow direct and indirect pathways. Direct effects relate to animal trampling and excretion, while indirect effects are mediated by changes in vegetation structure and function. We present a simplified model of a grazing system, integrating both direct and indirect effects of livestock on soil physical properties. Grazing animals affect soil and vegetation properties through the action of treading, defoliation, and excretal returns. This may result in soil compaction and/or poaching damage to the pasture, which may recover as a function of the effectiveness of abiotic (e.g. wetting-drying cycles) or biotic (e.g. roots and worms activity) mechanisms of structural resilience. In addition, defoliation and excretal returns impact on carbon and nutrient cycling in soil, which involve particular responses of soil organisms. Soil pores are the habitat for microbes and meso- and microfauna, which in turn are responsible for biotic mechanisms of soil structural resilience. In this chapter, we review the various effects of grazing on soil physical properties, carbon and nutrient cycling in forage production systems. We also discuss some management implications focusing on possible ways of minimizing negative grazing effects as well as  recovering desirable soil properties for sustainable production.