Trends and Developments in Hog Manure Management: 1998-2009
by
Nigel Key,
William McBride,
Marc Ribaudo, and
Stacy SneeringerEconomic Information Bulletin No. (EIB-81) 39 pp, September 2011
What Is the Issue?
Over the last decade, U.S. hog industry production has shifted
to fewer and larger operations that specialize in a single phase of
hog production and the use of production contracts. Consolidation
of operations has meant that an increasing volume of manure is
often produced on farms with less cropland per animal for spreading
the manure. A higher manure-to-cropland ratio has magnified the
risk that manure nutrients (nitrogen, phosphorous, and potassium)
and pathogens might flow into ground and surface water due to
overapplication of manure on crops or leakage from manure storage
facilities. These runoff contaminants can harm aquatic life and
livestock and affect human drinking water. In addition, increased
concentration of hogs per farm has led to conflicts with nearby
residents or communities over odor and air quality. Legislative
initiatives, such as the Clean Water Act and various State
regulations, have implemented environmental policies to mitigate
the risk of water pollution and reduce conflicts. Despite the
pronounced shifts in hog industry structure and regulation, little
information exists for assessing how these changes have affected
manure management practices and environmental quality. Using data
from three surveys of hog farmers, the authors shed light on these
issues by examining how hog manure management practices vary with
the scale of production and how practices have changed since
1998.
What Are the Study Findings?
• Hog farm operators altered their practices between 1998 and
2009 in ways that suggest intent to manage manure in a more
environmentally sound manner. In 2009, operators were more likely
to have comprehensive nutrient management plans and, accordingly,
to have increased their efforts to apply manure at rates not
exceeding the nutrient needs of the crop. They were more likely to
have applied manure over a larger share of their cropland and to
have increased their use of feed additives that reduce phosphorus
in hog manure, increased the nutrient testing of manure, and
removed excess manure from their premises. They were less likely to
have added commercial fertilizer to crops receiving manure.
• Changes in manure management practices and outcomes from 1998 to
2009 are related to structural changes in hog production,
particularly the increase in farm size and regional shifts of
production. The changes include more use of pit/tanks and less of
lagoons for manure storage; a decline in spreading solid manure, as
well as in spreading liquid manure without incorporating it into
the soil; and less intensive manure application by the largest
farms.
• Environmental policies are likely behind some of the observed
patterns of change in hog manure management between 1998 and 2009.
For example, the relatively slow growth in production in the
Southeast compared with the Heartland may be partly attributable to
State regulations in North Carolina designed to reduce risks
associated with manure lagoons. Nationally, greater use of
comprehensive nutrient management plans, as well as a decline in
intensity of manure applications by the largest operations, may be
in response to Federal and State policies designed to reduce
overapplication of manure nutrients. These changes suggest that
larger hog operations are altering their manure management
decisions in response to legal nutrient application constraints and
that environmental policy is contributing to the adoption of
conservation-compatible manure management practices.
How Was the Study Conducted?
This study uses information from surveys of U.S. hog producers
conducted in 1998, 2004, and 2009 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 the authors to document
the current state of manure management and track producers' manure
management practices during a period of rapid change in the hog
industry. Data from the surveys are disaggregated by farm size
according to the number of animal units produced (by 1,000 pounds
of live animal weight). Because larger hogs produce more manure,
animal units provide a consistent measure for comparing manure
handling trends among farms with different levels of manure
output.