Management Practices for Agricultural Nonpoint Sources
Management
Practices for Agricultural
Nonpoint Sources Appendix
A. Water Quality Protection
Program Committee
Members Appendix
B. TMDL Schedule for Impaired
Waters in Sanctuary
Watersheds. Appendix
C. Existing Laws and Programs
Related to Agricultural Nonpoint
Sources The term "BMP" is misleading, however. It cannot
be said that any so-called BMP will be the most
effective option in any particular circumstance.
Experience, professional judgment, and
experimentation are always required for the
successful implementation of appropriate pollution
controls on a site-specific basis. For this reason,
the term "management practices" is generally used
in this document rather than BMP. Such generally effective "Best Management
Practices" are described in detail in a variety of
other documents resulting from a wide range of
research, management studies and plans. These
include the State Water Resources Control Board
(SWRCB) and the California Coastal Commission's
Management Measures to Address Sources of Nonpoint
Pollution affecting California Waters, the NRCS
Field Office Technical Guide, Department of
Pesticide Regulation (DPR) and UCCE publications,
and the watershed-specific plans cited in the
bibliography. Examples of these agricultural practices
discussed in this document are not meant to imply
that a prescriptive menu of "one size fits all"
preferred practices be established for the
watersheds draining to the Sanctuary.
Identification of the most appropriate controls for
site- and crop-specific conditions is best made by
the landowner/operator relying on technical sources
of expertise such as NRCS, UCCE, Agricultural
Commissioners, private professional consultants,
private agricultural industry associations, and
local outreach agents such as the Resource
Conservation Districts (RCDs) and Community
Alliance with Family Farmers (CAFF). The WQPP
recognizes the importance of supporting the
continued evolution of improved agricultural
management practices through public and private
initiatives, utilizing economically sound adaptive
management practices. Erosion, sedimentation and
runoff A wide variety of management practices are
used to varying degrees in the watersheds that
drain to the Sanctuary to reduce the impacts of
runoff, erosion and sedimentation. Soil and water
conservation practices to help retain sediment and
reduce runoff include berms, water bars, sediment
basins, drainage ditches, field drains and sumps,
underground outlets, contour plowing, and drip
irrigation. They also include grassing of waterways
and field roads, vegetative buffers, windbreaks,
cover cropping, mulching, retention of residual dry
matter and minimum stubble heights, specialized
treatment of logging slash, encouragement of
perennial grasses on grazing lands, and fencing and
offsite watering on grazing lands. On some sites, sediment basins, water detention
basins, and vegetative buffer strips at the edges
of fields and waterways can help filter runoff and
collect sediments and associated chemicals; grassed
waterways and field roads can convey runoff and
prevent erosion, trap sediments and use excess
nutrients; underground outlets and furrow pickup
lines can direct excess runoff from slopes to
sediment basins for settling; diversions (earthen
berms) can be used to direct runoff into natural
channels, vegetated slopes or sediment basins.
Cover cropping, critical area plantings, mulching,
contour cultivation, furrow alignments, grade
stabilization structures, and a variety of other
management practices are also employed to reduce
on-site erosion and runoff. A variety of practices
are also available for rural road erosion control,
and for biotechnical approaches to bank
stabilization. Most management practices can be successfully
adopted by individual growers or ranchers, while
others may function best as part of a collaborative
project among a group of neighbors. Water that moves away from crops may have
unintended consequences of increasing erosion, and
transporting nutrients and pesticides away from
crops and into surface or ground water where they
become pollutants. This water loss can also be an
economic loss for the grower since it does not add
to crop productivity although electrical costs were
incurred for the pumping, and it contributes to
ongoing overdrafting of the aquifers in the Central
Coast region. Water conservation practices underway in varying
degrees throughout the watersheds include utilizing
the California Irrigation Management Information
System (CIMIS) or other irrigation scheduling
guidelines, applying such technologies as drip or
micro-irrigation and automated timers or controls
with moisture sensors, regular inspections/repairs
of the irrigation system, and increasing the
uniformity in distribution of water. Water
conservation practices also include capture of
runoff and recycling of irrigation water to reduce
water use (e.g., tailwater return systems, nursery
recycling systems), the application of mulch, and
reducing the impacts of runoff from impervious
surfaces (e.g., greenhouses) by capturing water
runoff from winter rains and using it for
irrigation. Additional water supply developments
include retention and detention ponds to capture
winter rains for groundwater recharge and for
irrigation use to reduce use of creeks in the
summertime. Excess nutrients that move off-site into surface
or ground waters may lead to environmental and
public health concerns, and may represent an
economic loss to the grower since they are no
longer contributing to crop productivity. A range
of fertilizer management practices are employed in
the region based on attempted estimates of
appropriate agronomic rates, but accurate
determination of the agronomic rate is dependent on
a number of crop- and site-specific variables. Management measures, underway to varying degrees
throughout the region, include minimization of
water and nitrogen loss by leaching and runoff
through effective application and timing of
irrigation water, utilizing CIMIS or other
irrigation scheduling guidelines; using multiple
small doses of nutrients rather than one or two
large applications; preapplication testing of
nutrient levels in soil or plant tissue;
consideration of the nitrogen content of irrigation
water in making fertilizer decisions; the use of
slow-release nitrogen; avoiding fertilizer material
spills during transport, storage and application;
and various techniques to position and concentrate
the fertilizer near the crop roots, instead of
leaving it spread out over 100% of the field. Where
appropriate and economically practical, leaching
and runoff of remaining nitrogen from fallowed
lands may be minimized through the use of cover
crops, and numerous types of organic materials may
be incorporated into the soil such as crop
residues, cover crops and manures. Vegetative
buffers around fields may also be used in some
locations to reduce off-site transport of
nutrients. Considerable research is underway via UCCE and
the industry-financed Fertilizer Research and
Education Program to refine management techniques
for the specialized vegetable production on the
Central Coast to reduce potential nitrate
contamination while increasing the efficiency of
fertilizer and water use. Growers should be able to
use this research to continually modify and improve
their management practices. Flood events, storm water runoff, and irrigation
can all cause offsite transport of persistent
pesticides which are no longer in use, such as DDT
and toxaphene. Although flood events can be reduced
in frequency and severity, they cannot be
eliminated; and severe flooding can overwhelm the
most prudent land management practices. Reduction
of offsite transport of old persistent pesticides
from ordinary stormwater runoff and irrigation
return flows, and to some extent from flood events,
will depend on erosion control practices, since
these compounds often remain adsorbed on soil
particles for long periods of time. A range of
potential management practices for erosion control
were identified above. Growers do not intentionally apply pesticides
excessively, since application and purchase are
significant business costs. County Agricultural
Commissioners regulate usage of restricted
materials, issuing permits which are specific as to
the pesticides used, crops treated, application
method and field locations. Pest and disease
outbreaks, consumer demand for unblemished
products, regulatory fruit and vegetable quality
standards, and food processor "zero tolerance" for
insect damage will continue to be important factors
necessitating the use of pesticides in production
agriculture. However, ongoing efforts to research
and develop genetically disease-resistant plant
varieties, biological control agents, Integrated
Pest Management Systems (IPM) and environmentally
benign chemical control agents are creating a
greater variety of effective pest control options
for growers to utilize. Many growers in the watershed use some form of
IPM techniques, to varying degrees. These
techniques include closer monitoring of pest
populations in the field to detect and target pest
buildups; use of cultural, physical and biological
controls before consideration of pesticide
application; establishment of an economic threshold
for each pest buildup problem on the crop beyond
which it becomes cost-effective to apply
pesticides; and use of non-chemical techniques
where appropriate. IPM relies on the targeted use
of pesticides when necessary and recognizes that
existing biological controls are not always
appropriate or effective. This suggests a need for
continuing investment in the development of
commercially feasible IPM tools. Additional management practices which are
underway in some areas include alternatives to the
"clean farming" approach of complete weed control,
such as use of hedgerows and grass plantings. Where
appropriate, they may also include encouragement of
native habitat that can harbor beneficial
insects/wildlife (i.e., those that prey on pests in
areas close to fields) as a method of reducing the
need for pesticides. In discussing pesticide management practices, it
is important to also recognize that homeowners
often use high-risk products with little or no
knowledge about effects, proper use, or disposal.
Education for urban residents about potential
impacts and ways to reduce runoff of pesticides and
fertilizers is being conducted as part of the
WQPP's Urban Runoff Plan. The number of confined animal facilities,
dairies and poultry ranches has decreased greatly
on the Central Coast over the past 30 years.
However, these facilities still exist, as well as
small rural ranchettes with recreational livestock,
and may present a localized threat to water quality
through runoff of sediments, nutrients and
pathogens. The larger facilities are regulated by
the RWQCB. Smaller unregulated facilities have a
range of management practices in use to varying
degrees, including dikes and diversions to reduce
contamination from manure areas; water and sediment
control basins; establishment of vegetative cover
or surfacing with suitable materials in heavy use
areas; liquid containment structures for waste
storage and treatment; reducing or rotating access
of livestock to riparian areas; use of vegetative
filter strips to remove sediment, organic matter
and other contaminants from runoff and wastewater;
and composting facilities. Although the management practices described
above address irrigated agriculture and confined
animal facilities, the region's watersheds also
contain extensive expanses of grazing lands.
Effectively managed grazing lands are an important
part of a healthy watershed, providing sites for
recharge, wildlife habitat, slowing runoff and
filtering potential pollutants. The following
discussion adapted from the California Rangeland
Water Quality Management Plan describes water
quality issues and management practices for grazing
lands.13 Livestock and wildlife's use of rangelands may
impair beneficial uses of water by adding inorganic
and organic sediments and bacterial contaminants to
water, and by physically altering riparian and
instream habitats. Animals may affect soil
compaction and removal of vegetation which can, on
some sites, decrease infiltration rates and
increase erosion. Management practices underway to varying degrees
throughout the region's grazing lands include
livestock management practices which assist with
the control, time, frequency or intensity of
grazing, in order to maintain sufficient vegetative
cover to protect soil and enhance desired
vegetation such as perennial grasses. Such
practices include prescribed grazing, feeding and
salting locations, and alternative sources of water
and shade. Structural improvements (e.g., water
development, fencing, erosion control, etc.) and
structures associated with normal livestock
production operations such as barns and corrals may
be used to facilitate grazing management. Land
treatments (e.g., burning, mechanical manipulation,
seeding, weed control) may be used to manage
vegetation, reduce erosion, and improve range or
wildlife habitat. Improving the quality of grazing lands has
important benefits to both the rancher and the
environment, if done in an economically viable and
sustainable fashion. Healthier soil and grass, and
greater control over livestock use patterns
increase agricultural production. Appropriate
grazing practices may promote a diversity of
plants, protect waterways, reduce erosion, reduce
fuel loads and are key to the long-term health of
the region's watersheds and for meeting water
quality goals. The State Water Resources Control Board has
endorsed the California Rangeland Water Quality
Management Plan (RWQMP) which was developed with
the assistance of the California Board of
Forestry's Range Management Advisory Committee to
be the rangeland component of the state's Coastal
Nonpoint Source Plan required by the Coastal Zone
Act Reauthorization Amendments of 1990. The RWQMP
is currently being implemented within the Central
Coast region through a series of formal "short
courses" conducted by the University of California
Cooperative Extension and NRCS, with the assistance
of individual county Cattlemen's Associations and
county Farm Bureaus, and under the oversight of the
RWQCBs. Continuing and building on these short
courses is addressed in Section 2 of this
document. As indicated above, the management practices
discussed here are not meant to be a prescriptive
list of practices, but simply to illustrate the
range of practices frequently cited as being useful
for protecting water quality. Effective management
practices for specific sites and crops are best
determined by the individual landowner relying on
available technical expertise, and will continue to
evolve as additional research and technology
becomes available. Self-monitoring, as discussed
later in Section 1 and Strategy 2-7, will play an
important role in helping growers determine the
effectiveness of management practices for their
specific conditions. Although the available data support general
conclusions about the mechanisms of pollutant
transport from nonpoint sources through the
watershed, the limited level of understanding of
hydrological systems and the location, significance
and mechanics of nonpoint sources limits our
ability to control pollution through the
prescriptive application of effective management
practices. Although much can be accomplished with
existing information on management practices,
effective control of pollutant sources will require
an ongoing planning and adaptive management
process. This should include development of a
baseline for sediment transport and other
pollutants in the watershed, further research into
the identification of both natural and
human-induced sources, and assessment of their
significance. It should also include refining
general classes of management practices to address
site-specific conditions, monitoring near- and
long-term results, and encouraging continual
evolution of practices to improve source
control. In considering ways to address water quality
issues in the watersheds that drain into the
Monterey Bay National Marine Sanctuary, several
related problems were cited by growers and
ranchers, agricultural representatives, resource
management agencies and the public during the
initial WQPP workshops held in Salinas,
Watsonville, and Half Moon Bay. Various
institutional and economic barriers were identified
that impede the development and adoption of
agricultural practices that improve water quality.
These barriers ranged from inaccessible technical
information and economic analyses for choosing
appropriate practices, to insufficient funding or
incentives for trials or installation, to
regulatory hurdles that may be disincentives to
making improvements. Although many management practices produce water
quality improvements, site-specific knowledge and
voluntary implementation of these practices is not
as widespread as it could be. Existing agricultural
organizations with extensive membership networks
such as Farm Bureaus could play a greater role in
expanding development and implementation of
effective management practices. Developing greater
public understanding of the complexity of the
issues and the importance of agricultural lands
will also be important for the WQPP's nonpoint
source components to succeed. In developing this document, participants
generally looked for a range of solutions that
would enhance and protect water quality, while
sustaining the economic viability of agriculture.
Approximately 40 initial recommendations by
participants fell into six strategy categories:
identification and adoption of more effective
management practices through development of
industry networks; expansion and coordination of
technical assistance/outreach; public education and
public relations; regulatory coordination/permit
streamlining for conservation measures; improved
funding mechanisms and tax incentives; and
strategies for public lands and rural roads. Strategies in Section 1 of this document outline
a framework for utilizing existing industry
networks such as Farm Bureaus and other
agricultural groups in establishing an agricultural
water quality program, under the umbrella structure
of the WQPP, and in cooperation with the Regional
Water Quality Control Boards. These strategies,
added by the Central Coast Farm Bureau Coalition,
are key to ensuring on-the-ground implementation of
management measures by local growers. Strategies in
Sections 2 through 5 deal with technical outreach
and education, funding and incentives, and
coordination/streamlining of the existing
regulatory system to reduce barriers to the
development and implementation of erosion control
practices that may require the approval of more
than one regulatory agency. Section 6 addresses
nonpoint issues on public lands and rural
roads. Table 1 summarizes each of the strategies, the
key activities involved, and a general priority for
implementation. For strategies indicated as high
priority, we expect substantial implementation to
be underway in the next three to five years. Section 1:
Agricultural Industry
Networks 1-1 Establish regional industry
networks as framework for addressing
nonpoint source management High (implementation has begun) 1-2 Identify priority sites for 1-2
joint projects High (pilot project sites already
identified) 1-3 Implement nonpoint source
management practices using industry-led
local Watershed Working Groups High Section 2:
Technical Information and
Outreach 2-1 Compile/distribute technical
information on agricultural conservation
practices High 2-2 Strengthen referral network and
cross-training for technical field
staff High 2-3 Increase agency staff time to
provide technical field support and
prevention efforts High 2-4 Strengthen information transfer
from industry to agencies Medium (link with strategies 3-3 and
4-3) 2-5 Strengthen grower/rancher peer
advisory networks High (link with Section 1
strategies) 2-6 Evaluate and distribute information
on cost-effectiveness of management
practices High 2-7 Develop and promote self-monitoring
tools for conservation management
practices High (link with strategy 1-3) Section 3:
Education and Public Relations
3-1 Increase public knowledge of and
support for agriculture and agricultural
conservation measures Medium 3-2 Increase grower and public
awareness of watershed-based
management High 3-3 Increase agency staff understanding
of agriculture High (link with strategies 2-4 and
4-3) Section 4: Regulatory Coordination
and Streamlining 4-1 Develop user-friendly permit
guidebooks and central locations for
permit information Medium 4-2 Develop regional or watershed-based
permits for conservation management
practices High (implementation has begun in two
watersheds) 4-3 Improve collaborative efforts
between regulatory agencies and
landowners High (link with strategies 2-4 and
3-3) Section 5:
Funding Mechanisms and Incentives
5-1 Improve agricultural community's
knowledge of and access to funding
sources High 5-2 Facilitate availability of 5-2
low-cost labor and trained assistance for
conservation field projects Medium 5-3 Broaden applicability of cost-share
programs and streamline application
process Medium 5-4 Increase understanding of existing
tax benefits Medium 5-5 Improve tax incentives for
implementing conservation measures Medium Section 6: Public Lands and Rural
Roads 6-1 Provide for maintenance practices
to address sedimentation on public roads
and waterways High 6-2 Reduce sedimentation from rural
unsurfaced roads and from surfaced roads
that are not maintained High 6-3 Improve conservation measures on
agency/public trust lands High
For many pollutants, a number of generally
effective management practices (termed best
management practices or BMPs) for addressing
agricultural nonpoint sources have been developed.
Many of these "BMPs" are now incorporated into the
technological baseline of modern American
agriculture and are so broadly implemented that
they are taken for granted by the public as part of
the agricultural landscape. These include basic
measures for soil and water conservation, pesticide
and nutrient application, handling of livestock
wastes, and grazing management. Additional BMPs
beyond this baseline are also used to varying
degrees by growers, ranchers and forest landowners
in the watersheds draining to the Sanctuary.
Summary of Strategies and Implementation
Priorities
 |
 |
Home | Introduction | Visitors | Education | Research | Protection | Calendar | Foundation | Search
Credits
For comments or question please refer to the Webmaster
Last modified on: August 6,
1999