Changes in Manure Management in the Hog Sector: 1998-2004
by
Nigel Key,
William McBride, and
Marc RibaudoEconomic Information Bulletin No. (EIB-50) 29 pp, March 2009
Economic competition has driven rapid changes in the U.S. hog
industry over the last 10 years. Production has shifted to larger
operations that increasingly specialize in a single phase of hog
production and are organized under production contracts. This
expansion and consolidation means that fewer operations now manage
an increasing volume of hog manure, magnifying environmental risks
if it is mismanaged. Pollutants such as nutrients (nitrogen and
phosphorus), ammonia, methane, and odor can originate from
production houses where animals are kept, from manure storage
structures such as tanks and lagoons, or from fields where manure
is applied.
What Is the Issue?
The changing structure of hog farms is altering manure
management practices, as larger operations seek to manage nutrients
on a limited cropland base. At the same time, strengthening of the
Clean Water Act with regard to runoff from manure nutrients, State
regulations like the 1997 moratorium on hog farm expansion enacted
by North Carolina, and local conflicts over odor are requiring
producers to alter their manure management practices. Information
about the effects of recent policies and structural changes on
manure management technologies and practices, the use of nutrient
management plans, and manure application rates is useful for
evaluating the effectiveness of environmental policies and
determining future policy needs.
What Are the Major
Findings?
Over 1998-2004, the total number of U.S. hog operations fell by
about 40 percent, and the average inventory grew from 2,589 to
4,646 head per farm. Data from hog producer surveys administered in
1998 and 2004 indicate that large hog producers (1,000 animal units
or more) are altering their manure management practices to mitigate
the environmental effects of increased concentration. In
particular, the largest farms removed more manure from their
operations (especially by giving it away for free) and applied less
commercial fertilizer to crops receiving manure in 2004 than in
1998. Also, in accordance with EPA regulations, large hog
operations conducted more nutrient testing of manure, increased the
use of microbial phytase in feed (which reduces nutrients in
manure), and increasingly followed comprehensive nutrient
management plans. Additional trends that suggest greater adherence
to environmental regulations by the largest hog farms include: (1)
a decline in the spreading of solid manure and liquid manure
without physically injecting it into the soil (these two practices
increase the risk of nutrient loss to the atmosphere and runoff);
(2) a decline in the quantity of manure applied per acre; (3) a
decline in the nutrients excreted per animal due to an increase in
feed efficiency; and (4) an increase in the share of farms removing
manure from their operation.
The increasing concentration of hog production on large
operations is expected to continue, meaning that manure management
will continue to be an important issue to the hog industry and to
others concerned with its environmental impact. Results of this
research suggest that there still is significant room for reducing
the environmental impact of manure through improved management. For
example, hog operations, on average, apply manure to less than 30
percent of available crop acreage. Policy incentives, along with
technological innovation, are likely to play an important role in
the future of hog manure management and its environmental
impact.
How Was the Study Conducted?
This study uses information from surveys of U.S. hog producers
conducted in 1998 and 2004 as part of USDA's annual Agricultural
Resource Management Survey (ARMS). The detailed surveys cover a
cross-section of U.S. hog operations and collect information on
production costs, business arrangements, production facilities and
practices, and farm operator and financial characteristics. The
surveys also provide information about manure storage and handling,
fertilizer use, manure application techniques, Environmental
Quality Incentives Program (EQIP) payments, the use of
comprehensive nutrient management plans, and manure application
rates. The data allow us to document the current state of manure
management and track producers' responses to existing and
anticipated manure-related regulations. Data from the surveys are
analyzed by farm size according to the number of animal units
(1,000 pounds of live animal weight) produced. Because larger hogs
produce more manure, animal units provide a consistent measure for
comparing farms that produce hogs at different stages of the
production cycle.