California Dairies:
Protecting Water Quality
University of California
Agriculture and
Natural Resources
Publication 21630
A primer for consultants,
local government
agencies, and lending
institutions
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
California’s Dairies and the Environmen
t:
The Promise and the Challenge
. . . . . . . . . . . 3
How Are Dairy Producers
Responding to the Challenge? . . . . . . . . . . . . .
5
A. Dairies with Irrigated Cropland . . . . . . . . . . 6
Management Measure A1.
Assess dairy farm nutrient balance and upgrade
the manure recordkeeping system . . . . . . . . . . . . . . . . . .
6
Management Measure A2.
Transfer manure nutrients off-farm . . . . . . . . . . . . . . . . . .
7
Management Measure A3.
Modernize the liquid manure distribution system
. . . . 7
Management Measure A4.
Increase manure storage capacity and
reduce waste volume
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Management Measure A5.
Apply nutrients to crops at agronomic rates
. . . . . . . . 8
Management Measure A6.
Improve irrigation system efficiency and
water distribution uniformity
. . . . . . . . . . . . . . . . . . . . . . . 9
B. Dairies with Non-irrigated Pasture
and Hay Fields
. . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Management Measure B1.
Limit manure runoff from animal
confinement areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10
Management Measure B2.
Prevent runoff from manured fields from
entering surface waters
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
C. Dairies with Limited Cropland . . . . . . . . . . . 12
Management Measure C1.
Develop off-farm markets for solid manure . . . . . . . . .
12
Management Measure C2
.
Manage corrals so they do not become sources
of pollution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Management Measure C3.
Minimize liquid waste volume requiring
off-farm disposal
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Additional Reading . . . . . . . . . . . . . . . . . . . . . . . .
15
Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Acknowledgments
. . . . . . . . . . . . . . . . . . . . . . . . 16
1
This guide
summarizes
the practical
approaches and
technologies
that have been
implemented by
progressive dairy
producers to
protect surface
and groundwater
quality.
Introduction
California Dairies:
Protecting Water Quality
A primer for consultants, local government agencies,
and lending institutions
M
ilk is California’s number one
agricultural commodity, with a
farmgate value in 2004 of more than five billion dollars. For
many years dairy farming has
provided a stable economic base
for rural communities in the
state. California’s dairy farms
produce milk of unsurpassed
nutritional quality used to make
award-winning cheeses, ice
cream, yogurt, butter and many
other products for both local
and international markets.
In recent decades, many changes have
taken place on the state’s dairy farms.
The number of dairies has decreased,
while average herd size has increased.
Dairy producers have made substantial
upgrades to milking facilities and animal
housing, improving sanitation and
animal comfort. Change in the size and
structure of dairy facilities is mainly a
result of the increasing cost of labor, land,
and water in California as well as the increased demand for affordable milk,
cheese, and other products. Some dairy
producers have developed niche markets
for organic or other specialty products.
Dairy farming has in some ways
enhanced the state’s environmental quality
— for example, by preserving open space
and wildlife habitat. As dairy producers
have worked to remain profitable and meet
consumer demands,
they also have been
faced with increasing
scrutiny by state and
local environmental
health and planning
agencies and by
environmental groups.
Increased
stringency of
regulations and public
scrutiny have pushed
dairies — especially
those expanding or
newly constructed —
to invest in improved
11
2
manure management
systems. Research
by University of
California scientists and
others has increased
the understanding
of environmental
impacts associated
with dairies and has
led to development
of improved technologies. Wide-scale
adoption of farming practices that
protect the environment depends on
awareness and support of businesses
such as lending institutions, consulting
engineers, and crop management
companies, as well as regulatory agencies.
This guide summarizes the practical
approaches and technologies that have
been implemented by progressive
dairy producers to protect surface
and groundwater quality. Because
each dairy is different, and practices
must be tailored to each situation, the
management practices described here
should be viewed as illustrations of
the potential for improvement and not
as recommendations for all dairies.
Each dairy is different
and operates under
a different set of
constraints; practices
must be tailored to
each situation.
3
*Putnam, D., M. Russelle, S. Orloff, J. Kuhn, L. Fitzhugh, L. Godfrey, A. Kiess, and R. Long. 2001. Alfalfa,
Wildlife and the Environment. California Alfalfa
and Forage Association, Novato, California.
D
airy farming as practiced in
much of California provides
environmental services to
society. Most dairies in the state combine
livestock and crop production on the same
property, and this combination has certain
environmental advantages compared
to farming systems that have only crop
production or only livestock. These
environmental benefits are a result of:
• Production of deep-rooted, high
nutrient-uptake forage species,
which provide year-round
protection of vulnerable soils.
• Recycling of manure nutrients and water to crops on the farm.
• Provision of wildlife habitat, open space, and view corridors. Pasture
and hay crops provide critical
bird, mammal, amphibian and
reptile habitat in California.*
However some aspects of dairy
farming in California increase the
risks to water quality such as:
• The location of some dairies on well-drained porous soils, which
can increase the potential for
leaching of nutrients and salts
to groundwater aquifers.
• Use of manure flush systems that generate a large volume of dilute
nutrient liquid, which cannot
economically be transported off-
farm and must be distributed
to crops via the often less-than-
perfect flood irrigation systems. • Uncertainty in the crop nutrient value
of manure. This sometimes leads dairy
producers to apply ‘insurance’ rates of
commercial fertilizer to crops that have
already received manure. This decreases
the percent of applied nutrients that
is recovered by crops and increases
the risk of water quality impacts.
• Limited availability of flat land for manure application.
Application to steeply sloping
land carries the risk of runoff and
contamination of surface waters.
California’s Dairies and the Environment:
The Promise and the Challenge
3
4
*Data drawn from Meyer, D.M., I. Garnett, and J.C. Guthrie. 1997. A survey of dairy
manure management practices in
California. Dairy Sci. 80:1841-1845, and from
Dairy manure nutrient management survey
results – September 2004, unpublished
report available from the University
of California Sustainable Research
and Education Program, Davis, CA.
Overcoming these
limitations can be both
costly and technically
challenging. However, in
recent years, solutions with
less environmental impact
have been developed and are
being used by an increasing
number of dairy producers.
For example, the percent of
dairy producers reporting
use of mechanical screens
and settling basins to remove
coarse solids from manure
flush water in Tulare, Fresno,
and Madera Counties
increased significantly from
1994 to 2003.* Several
organizations have supported
the development and
promotion of these solutions,
including the University of
California, the USDA Natural
Resources Conservation
Service, and an industry-
government partnership,
the California Dairy Quality
Assurance Program.
University of California
Cooperative Extension
The University of California Cooperative
Extension (UCCE) is the outreach
arm of the land grant college system
in the state. The UCCE is comprised
of county advisors and campus-based specialists in
agriculture, natural resources, youth, nutrition, family
and consumer sciences. Through applied research, field
testing and education, UCCE advisors and specialists
work to develop environmentally sound farming
methods. Contact information for UC county farm
advisors specializing in dairy science and agronomy
can be found at
http://ucanr.org/ce.cf m.
Natural Resources Conservation Service
The mission of the USDA Natural Resources Conservation
Service (NRCS) is to assist private landowners in
conserving or protecting soil and water quality. NRCS
defines “conservation” as wise use of natural resources
- soil, water, air, plant, and animal - in order to sustain
productivity of current and future generations. NRCS
accomplishes this mission by working directly with
local Resource Conservation Districts and Resource
Conservation and Development Councils. Contact
information for your local NRCS staff can be found at the
NRCS website
http://www.ca.nrcs.usda.gov/contact .
California Dairy Quality Assurance Program
The California Dairy Quality Assurance Program (CDQAP)
helps the state’s dairy producers understand and meet
federal, state, regional, and local requirements for
manure management and water quality protection. The
CDQAP is a partnership of California dairy organizations,
federal, state, and regional government agencies, and the
University of California Cooperative Extension. It offers
a voluntary certification program that assists producers
to comply with federal, state, and local environmental
regulations. Contact your UC Cooperative Extension
dairy advisor or trade organization for a current list of
courses and activities, or go to
http://www.cdqa.or g.
5
T
here are four essential components
that all dairies must develop if water
quality is to be protected. First, there
must be sufficient cropland to receive
recycled wastewater and manure at rates
matching the crop demand. Where the
milk herd is too large for the land base,
manure nutrients must be transported off
farm; and in that case, there must be some
assurance that the manure will be used in
an environmentally sound manner at its
final destination. Secondly, there must be
suitable storage for manure during periods
of rain and low crop nutrient demand so
that nutrients, salts, and pathogens can be
kept out of waterways. Third, there must
be a distribution infrastructure and
equipment to transfer
the manure nutrients
to cropland. Fourth,
management procedures
and recordkeeping
must
be in place to ensure and
document that wherever
manure is recycled, it is
applied at appropriate rates
and times and in a manner
that does not pollute water
or create a nuisance. This
publication summarizes
field proven methods and
equipment available to
California’s dairy producers to
meet these four requirements. The process of upgrading an existing
dairy facility to an ‘ideal’ dairy facility
takes time. As progressive dairy producers
have worked to improve their nutrient
management practices, they have
demonstrated a wide range of possible
solutions to the challenges facing them.
The specific measures taken by a
dairy producer to protect water quality
will vary with topography, climate, and
surrounding land use and availability.
Most of California’s 2000 (±) dairies
operate in one of three basic ways:
with irrigated cropland; with non-
irrigated pastures and hayfields; and
with little or no adjoining cropland.
How Are Dairy Producers Responding
to the Challenge?
Source: California Department of Food and Agriculture
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