Natural Resources, School of


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Chapter 11 in Forages: The Science of Grassland Agriculture, Volume II, Seventh Edition. Edited by Kenneth J. Moore, Michael Collins, C. Jerry Nelson and Daren D. Redfearn.


In most forage production systems, the nutrients needed for plant growth are provided by the microbially-mediated breakdown and release of plant-available mineral nutrients from dead plant tissues, livestock excreta, soil organic matter, and geochemically-bound mineral forms. Even in fertilized forage systems, determining appropriate fertilizer or manure application rates requires a “systems” approach on the part of the manager (Rotz et al. 2005; Wood et al. 2012). Fertilizer additions are simply one input in the system of inputs, outputs, pools, and fluxes that characterize nutrient cycling in a particular ecosystem.