Agriculture Reference
In-Depth Information
7 Sustainable Manure Management
A.B. Leytem, 1 * R.S. Dungan 1 and P.J.A. Kleinman 2
1 USDA-ARS, Kimberly, Idaho, USA; 2 USDA-ARS,
University Park, Pennsylvania, USA
Introduction
separate. The advent of commercial fertilizers
largely replaced the role of livestock manure as a
primary source of nutrients for crop production.
Networks for transporting feed and forages have
enabled the specialization and intensification of
animal production, with the number of animals
used for production of meat, milk and eggs
increasing from ~10 billion in 1930 to 68 billion
in 2002 (FAOSTAT, 2012). By 2000, it was esti-
mated that livestock were generating 101 and
17 Tg of manure nitrogen (N) and phosphorus (P),
respectively, per year (Bouwman et al ., 2009).
While the quantity of manure nutrients gener-
ated over this period increased, the growing dis-
integration of livestock and crop production has
left most modern livestock producers with a sur-
plus of on-farm nutrients.
Even greater concentrations of manure nutri-
ents are apparent at regional scales (e.g. Maguire
et al ., 2005). Potter et al . (2010) determined the
geographic distribution of manure N and P pro-
duced from the main livestock groups (cattle,
buffalo, goats, sheep, pigs and poultry) and
reported that the highest rates of N and P in
manures produced are found in the USA, parts
of South America, western Europe, East Africa,
northern India, eastern China and New Zealand.
Regions with concentrated animal production
that also use fertilizers in crop production have
Manure management has risen to the fore of
livestock production concerns in the developing
world, with implications to farming system
design, function and profitability, as well as
to environmental quality and human health.
Sustainable manure management, i.e. manure
management that balances the production, eco-
nomic and environmental concerns of manure
generation, handling, processing and end use,
requires concerted investment of resources and
time as well as a strategic approach to livestock
production that often extends well beyond the
farm gate. This chapter seeks to elucidate the
concerns underlying manure management
and the considerations of sustainable manure
management. While we provide a broad review
of salient issues, particular emphasis is placed
upon emerging areas of concern and innovation
in manure management.
To appreciate the challenges of manure
management in modern livestock operations, it
is instructive to consider the evolution of live-
stock production from traditional, diversified
systems with a high degree of integration
between feed and livestock production, to mod-
ern, specialized systems in which feed and live-
stock production are sometimes completely
 
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