MANAGING AGRICULTURAL NUTRIENTS IN MARYLAND'S
CHESAPEAKE BAY BASIN

Richard A. Weismiller
(Professor, Department of Natural Resource Sciences and Landscape Architecture, 2102 Plant
Sciences Building, University of Maryland at College Park, College Park, MD 20742-4452, U.S.A.)

Patricia M. Steinhilber
(Program Coordinator, Agricultural Nutrient Management Program, Department of Natural
Resource Sciences and Landscape Architecture, 2102 Plant Sciences Building, University of
Maryland at College Park, College Park, MD 20742-4452, U.S.A.)

Jennifer L. Salak
(Communications Coordinator, Agricultural Nutrient Management Program, Department of Natural
Resource Sciences and Landscape Architecture, 2102 Plant Sciences Building, University of
Maryland at College Park, College Park, MD 20742-4452, U.S.A.)


Abstract: During the 1970's, water quality in the Chesapeake Bay declined due to increased soil sediments and plant
nutrient inputs. One of the solutions proposed by government officials to improve water quality was to adopt a 40 percent
nutrient reduction goal, which was to be attained by the year 2000. This goal was outlined in the 1987 Chesapeake Bay
Agreement and was adopted by several states. As a result of the Bay Agreement, nitrogen and phosphorus loadings into
the Bay from point and non-point sources have decreased by over 16 million kilograms per year. Despite these
improvements, the 40 percent goal was not met by 2000 and the deadline was extended to the year 2010. To meet this new
deadline, government officials in Maryland have developed several new programs and policies such as the 'Tributary
Strategies' Program, the Maryland Nutrient Management Program and the Water Quality Improvement Act of 1998. The
purpose of the 'Tributary Strategies' Program is to reduce the amount of nutrients that enter the Bay from each of its
tributaries. One of the methods described in the 'Tributary Strategies' Program as playing a key role in reducing nutrients
from agricultural non-point sources is nutrient management planning. Nutrient management planning is a series of best
management practices aimed at reducing non-point source pollution by balancing nutrient inputs with crop nutrient
requirements. The Water Quality Improvement Act provides guidance to the Maryland Nutrient Management Program for
the development of nutrient management plans. These plans are developed by certified advisors working for the Maryland
Cooperative Extension and certified consultants working for private industry, and are based on soil and manure test results,
yield goals and residual nitrogen estimates to generate field-by-field nutrient recommendations. Since the Water Quality
Improvement Act was passed, advisors have written plans for over 91,000 hectares of farmland.

INTRODUCTION

The Chesapeake Bay, with an area of
area to water-volume ratio coupled with increased
approximately 5,960 square kilometers, is the
spring and summer halocline formation makes the
United States of America's largest estuary. It
Bay particularly vulnerable to the effects of nutrient
receives about half of its water volume from the
pollution. In 1976, concerns regarding declining
Atlantic Ocean and half from its 165,900 square
water quality within the Bay and its tributaries led to
kilometer watershed, which includes areas of six
a six-year water quality study of the Bay. About
states and the District of Columbia. The Bay is very
forty research projects coordinated by the
shallow, averaging approximately 6.5 meters in
Environmental Protection Agency (EPA)
depth. Compared to other coastal and inland bodies
documented declining water quality and reductions
of water, the Bay has a large drainage basin for the
in the numbers and diversity of fish, shellfish and
volume of water it contains. For the Baltic, this
submerged aquatic vegetation (SAV) in the
ratio is approximately 43.62 square kilometers of
Chesapeake Bay. Eutrophication and turbidity
watershed per cubic kilometer of water volume, and
caused by soil sediments and increases in plant
the ratios for many other water bodies are only a
nutrient inputs were considered to be the main
fraction of the Baltic ratio. This large watershed-
causes of these declines. Nutrient reduction was

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therefore considered to be a major consideration for
amount of nutrients that enter the Bay from each of
improving the habitat for benthic organisms and
its tributaries. Tributary strategies are important
fish. Reductions in nutrients would result in
because they provide the opportunity to integrate
reduced algal blooms and increased light penetration
nutrient reduction efforts through a wide variety of
to SAV. Water quality models simulating
initiatives and also provide a framework for a
ecosystem processes along with loading levels from
comprehensive approach to nutrient reduction.
1985 were used to establish a 40 percent reduction

goal for the amount of nutrients, particularly
Under Maryland's 'Tributary Strategies' Program,
nitrogen and phosphorus entering the Bay from
the state was divided into ten major watersheds and
point and non-point sources. This 40 percent
a tributary strategy was developed for each
reduction goal was outlined in the 1987 Chesapeake
watershed. Each watershed's nutrient loads were
Bay Agreement and was to be attained by the year
determined on the basis of point source loads and
2000. The signatories of the 1987 Bay Agreement
land use loading rates and areas. Several program
include Maryland, Virginia, Pennsylvania, the
and practice options for reducing nutrients exist
District of Columbia and the EPA. In 1997, it was
under the Maryland `Tributary Strategies' Program
realized that although much progress had been made
and each option has a specific goal. The options,
towards reducing the amount of nutrients entering
which have the highest importance in the statewide
the Bay, the 40 percent reduction goal for nitrogen
strategy of reducing nutrients, are building animal
would not be met. Therefore, work began on the
waste management systems, using conservation
2000 Chesapeake Bay Agreement. The 2000 Bay
tillage, planting cover crops, enhancing stormwater
Agreement focused on achieving and maintaining
management and implementing erosion and
the 40 percent reduction goal set in 1987 and also
sediment control plans. Another option, which is a
getting the Chesapeake Bay removed from the
high priority statewide strategy for reducing
federal list of impaired waters by the year 2010.
nutrients, is nutrient management planning.

The improvements that have occurred thus far, as a
Nutrient management planning is a series of best
result of the implementation of the 1987 Bay
management practices (BMPs) aimed at reducing
Agreement, include a decrease in the point source
nutrient non-point source pollution by balancing
nitrogen loads by over 7 million kilograms per year
nutrient inputs with crop nutrient requirements.
and a decrease in the point source phosphorus loads
Nutrient management planning is considered to be
by over 2 million kilograms per year. Nitrogen
one of the most cost-effective means of controlling
loading into the Bay from non-point sources has also
excessive nutrient applications. Table 1 provides a
decreased by over 7 million kilograms per year and
list of the goals set by the 'Tributary Strategies'
phosphorus loading from non-point sources has
Program and the progress that the combined
decreased by more than 454,000 kilograms per year
watersheds have made towards achieving those
(1). Despite these improvements, nitrogen loads
goals.
from both sources need to be reduced by another 18

million kilograms per year and phosphorus loads
Table 1 'Tributary Strategies' Program goals and
from both sources need to be reduced by an
watershed progress (as of 1998)
additional 454,000 kilograms per year (2). State
Program Option
Program Goal
Watershed
Progress
legislators believe that one key way in which non-
Animal Waste
1028 systems
567 systems
point source loading will be reduced is to rely on the
Management
tributary strategies that are already in place in some
Systems
Conservation
137,621 ha.
110,189 ha.
of the Chesapeake Basins.
Tillage

Cover Crops
67,715 ha.
39,532 ha.
TRIBUTARY STRATEGIES PROGRAM
Enhanced
54,635 ha.
8146 ha.

Stormwater
In 1992, the 1987 Chesapeake Bay Agreement
Management
Erosion and
7805 ha.
3226 ha.
was amended and as a result, each state (Maryland,
Sediment Control
Virginia, Pennsylvania and the District of Columbia)
Plans
agreed to develop their own 'Tributary Strategies'
Nutrient
351,095 ha.
335,364 ha.
Management
Programs by combining existing regulatory
Planning
programs with voluntary programs. The purpose of
Source: Maryland Department of Natural Resources Website
a 'Tributary Strategies' Program is to ensure that the
(http://www.dnr.state.md.us/bay/tribstrat/index.html)
40 percent reduction goal is met by reducing the

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MARYLAND NUTRIENT MANAGEMENT
attached to soil particles would pose little threat to
PROGRAM
water quality. Therefore, nutrient management

plans were based on nitrogen recommendations
Prior to the 1987 Chesapeake Bay Agreement,
only. However, researchers have discovered that
programs existed to implement some aspects of
under certain conditions there could be a significant
water quality improvement, but no program was in
amount of soluble phosphorus near the soil surface,
place to specifically address nutrient management
which can be carried to water bodies in surface
planning. However, it was known that
runoff. Also, these researchers have found that
implementation of nutrient management planning
some soils, primarily those that are shallow and
could play a key role in reducing the amount of
coarse textured, could have significant leaching of
nutrients from agricultural non-point sources. In
phosphorus to groundwater resources.
1989, the Maryland Department of Agriculture

(MDA) and the University of Maryland/Maryland
To address the phosphorus problem, the WQIA
Cooperative Extension (MCE) established the
mandates which type of nutrient management plan
Maryland Nutrient Management Program (MNMP).
(nitrogen- based or phosphorus-based) an
The primary focus of this program was to place 0.54
agricultural operation must have. For example,
million hectares of Maryland's 0.91 million hectares
farmers who use commercial fertilizers are required
of farmland under nutrient management plans by the
to have nitrogen and phosphorus-based plans
year 2000.
developed by December 31,2001 and implemented

by December 31, 2002. Farmers who apply animal
manure or bio-solids must have a nitrogen-based
WATER QUALITY IMPROVEMENT ACT
plan developed by December 31,2001 and
OF 1998
implemented by December 31,2002. Farmers

applying animal manure or bio-solids must also
Prior to 1998, it was the opinion that excess non-
develop phosphorus-based plans by July 1, 2004,
point source nitrogen from fertilizers and manures
and these plans must be implemented by July 1,
was the main threat to the Chesapeake Bay from
2005. Those who fail to obtain a nutrient
agricultural enterprises within Maryland. Thus,
management plan are subject to a $250
nutrient management plans were based on nitrogen
administrative penalty, a $100 fine for each
recommendations only, and the adoption of these
violation after the first violation, recovery of cost-
plans by farmers was (with a few exceptions)
share grants for projects in violation of the law and
voluntary. In 1998, the Maryland state legislature
limits on future cost-share assistance.
passed the Water Quality Improvement Act

(WQIA), which according to MDA, "is designed to




The WQIA legislation applies not only to
protect the health of Maryland's citizens and its
traditional agricultural operations but other
waterways by establishing both short and long-term
agricultural operations as well. These operations
strategies for reducing nutrient levels in our rivers
include vegetable growers, organic producers,
and streams". Under the WQIA, all agricultural
nurseries, greenhouses, turf grass producers and
enterprises with an annual gross income of $2500 or
certain horse farms. In addition to agricultural
more and livestock operations with more than eight
operations, the WQIA affects nutrient applicators
animal units (one animal unit equals 454 kilograms)
working for the commercial fertilizer industry,
are required to have nutrient management plans.
private fertilizer applicators and poultry feed
These plans must now address both nitrogen and
distributors. According to the WQIA, applicators
phosphorus.
working for the commercial fertilizer industry must

be certified to write nutrient management plans or
Manure and other organic wastes generally
work under a consultant who is certified. Those
contain high levels of both nitrogen and phosphorus.
applicators servicing one or more hectares of non-
With the heavy applications of organic wastes to
agricultural land or state property are required to
fields to supply the nitrogen requirements of crops,
apply fertilizers in accordance with the
soils have built up excessive levels of phosphorus.
recommendations of the University of
This did not seem to be a problem since it had long
Maryland/MCE. Private fertilizer applicators
been the convention that phosphorus was relatively
applying fertilizers to more than four hectares of
immobile in the soil. Thus by controlling surface
agricultural land in which they own or manage are
runoff and the resultant soil erosion, the phosphorus
required to complete an MDA nutrient application

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education program once every three years. If private
structures requesting updated plans (3) Producers
applicators apply fertilizers to one or more hectares
using manure from other producers' operations (4)
of non-agricultural land or state property, they are
Producers having limited resources in that they
required to apply fertilizers in accordance with the
cannot afford nutrient management services
recommendations of the University of
provided by private industry (5) Producers
Maryland/MCE. Poultry feed distributors were
requesting assistance in order to meet WQIA
required by December 31, 2000 to add phytase or
requirements (6) All other Maryland agricultural
other enzymes to poultry feed in order to increase
producers who can benefit from MNMP educational
phosphorus use efficiency by the animal thus
resources. When developing nutrient management
reducing the amount of phosphorus in poultry waste.
plans, advisors use soil and manure test results,

realistic expected yield goals and estimates of
CERTIFIED ADVISORS AND
residual nitrogen to generate field-by-field nutrient
CONSULTANTS
recommendations. By 1998, there were

approximately 445,500 hectares of agricultural land
To facilitate nutrient management planning as
in Maryland under nutrient management plans.
mandated by the WQIA, the MDA in cooperation
Over the last 3 years since the WQIA was passed,
with a Nutrient Management Advisory Committee,
MCE advisors have written 3344 new plans for
administers a mandatory certification exam to those
Maryland farmland (totaling 91,293 hectares) and
who want to write nutrient management plans. To
1235 new plans for animal producers (3). In
renew a certification, individuals are required to
addition to writing plans, advisors perform other
attend 6 hours of continuing education training per
free services such as yield checks, pre-sidedress
year. The MNMP is responsible for implementing
nitrate tests (PSNT) for corn, collecting manure
the ever-expanding continuing education and
samples to be tested by the University of Maryland
training program. After becoming certified and
Soil Test Laboratory and manure spreader
licensed, private consultants and firms are required
calibrations.
to report their planning progress to the MNMP

annually. In Maryland, there are 219 certified
FREE SERVICES
private consultants, however only 107 are currently

writing plans. Since the WQIA was passed in 1998,
Advisors conduct yield checks to establish
private consultants have written 524 new nutrient
realistic yield goals on a field-by-field basis. Yield
management plans for approximately 43,081
goals are a critical factor in determining nitrogen
hectares of farmland (R. Cuizon, Maryland
recommendations for crops. Another free service
Department of Agriculture, personal provided by MCE advisors is the PSNT for corn,
communication). There are also 199 certified
which is the major field-crop in Maryland. The
consultants in Maryland's government agencies, and
PSNT is an in-season soil nitrate test taken when the
30 of those are MCE nutrient management advisors
corn is approximately 30 cm tall and provides an
based in county offices throughout the state. These
accurate measure of soil nitrate and the availability
publicly funded MCE advisors provide nutrient
of nitrogen over the growing season. This allows
management planning services to clients and also
farmers to tailor their fertilizer use to existing soil
emphasize how such planning enhances farm
nutrient conditions and reduce their use of 'insurance
profitability and improves water quality. Nutrient
N' fertilizer as a sidedress application. The PSNT
management advisors develop plans for many
can also predict the amount of N that will become
clients, however top priority is given to producers
available from previous legumes crops, manure or
with pollution problems, large livestock operations
bio-solids applications, soil organic matter and
and those in priority watersheds or the 'Chesapeake
residual nitrate. This test is best used on fields that
Bay Critical Area'. After plans are developed for
have received manure or biosolids, but should not be
producers in these high priority situations, advisors
used if commercial fertilizer is the only source of N
then develop plans for producers in the following
for corn production or the total N fertilizer
order of priorities: (1) Producers participating in the
application prior to sidedress (including preplant and
Manure and Poultry Litter Transport Programs (2)
starter band N) is more than 56kg/ha. MCE advisors
Producers referred by Soil Conservation Districts
use inexpensive, readily available commercial
(SCD) for animal waste management systems or
meters to produce rapid and reliable field specific
other cost-shared structures requiring nutrient
results. Since 1998, MCE advisors have conducted
management plans, or farmers with cost-shared
the PSNT on approximately 36,500 hectares of

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farmland resulting in an average reduction of
containment projects, MACS will pay up to $75,000
nitrogen application by 30kg/ha (4).
per project and a maximum of $100,000 (when

combined with other BMPs). To be eligible for the
Manure testing procedures are also provided free
MACS Program, an individual, or business must be
of charge by the MNMP through a grant from the
operating a farm in Maryland and must have
Maryland Department of Agriculture. These
excessive levels of soil, nutrients or pollution
services are provided to all farmers regardless of
running off into Maryland's waters.
whether or not they adopt a voluntary nutrient

management plan. Advisors demonstrate the correct
Two other cost-share programs not listed in Table
sampling techniques recommended by the
2 are the Manure Transport (5) and Poultry Litter
University of Maryland Soil Test Laboratory, which
Transport (6) Programs. These programs were
is responsible for conducting the analyses on these
established in 1999 as four year, $750,000 pilot
manure samples. Advisors also perform manure
projects, with the purpose of providing cost-share
spreader calibrations on-farm to ensure the tested
assistance (up to $20 per ton) to animal producers
manure is spread at the agronomically correct rate
for transporting excess manure off of their farms.
for the crop being grown.
The programs were designed to help producers make

the transition to phosphorus-based nutrient
BEST MANAGEMENT PRACTICES
management plans (as mandated by the WQIA), and

are open to those who have high soil phosphorus
A range of other initiatives complements the
levels or inadequate land to fully use their manure.
MNMP's free services. These initiatives (Table 2)
Farmers on the receiving end of the transport
are provided by the Maryland Agricultural Water
programs are eligible to accept manure and poultry
Quality Cost-Share Program (MACS) to help
litter only if these wastes can be safely land-applied
farmers install BMPs.
according to an agronomic and environmentally

sound nutrient management plan.
Table 2 BMPs eligible under the MACS Program

Animal Waste
Field
Roof Runoff
Management
Borders/Windbreaks
Management
UNIVERSITY OF MARYLAND
Systems
RESEARCH
Conservation Cover
Filter Strips
Sediment Basins

In addition to the cost-share programs provided
Contour
Grade Stabilization
Spring
by MDA for the installation of BMPs, other nutrient
Farming/Orchards
Structures
Developments
reducing strategies are being researched by the
Cover Crops
Grassed Waterways
Stream Crossings
University of Maryland. These strategies include
reducing the amount of nutrients excreted in animal
Critical Area
Lined
Stream Fencing
wastes, developing cost-effective, low-impact
Plantings
Waterways/Outlets
nutrient and irrigation solutions for the nursery and
Dead Bird
Nutrient
Strip Cropping
greenhouse industries, generating up to date nutrient
Composting
Management
recommendations for the turfgrass industry,
Facilities
Services
Diversions
Riparian Buffers
Terrace Systems
reducing soil erosion and runoff from urban
landscapes and reducing phosphorus runoff from
agronomic fields.
Source: Maryland Department of Agriculture Website
(http://www.mda.state.md.us/resource/mawqcs10.htm)






The current focus of the Animal Nutrient
The purpose of the MACS Program is to provide
Management Program is to develop ways to reduce
cost-share assistance (up to 87.5 percent of cost) to
the amount of nutrients excreted in animal wastes by
farmers for the installation of eligible BMPs. Since
increasing nutrient retention. Researchers study
BMPs help reduce soil erosion and protect water
how all of the nutritional factors in the animals
quality, their use in certain situations is mandated
interact to affect nutrient availability and retention.
under the WQIA and the Chesapeake Bay Critical
The animals used in the studies include poultry, beef
Area Law. For all BMPs, except animal waste
and dairy cattle and striped bass under commercial
treatment and containment projects, the MACS
conditions. The specific projects in this program
Program will pay up to $20,000 per project and a
include determining the best combination of feed
maximum of $50,000 (when combined with other
additives to increase phosphorus retention in
BMPs). For animal waste treatment and
broilers, turkeys and laying hens, determining the

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phosphorus requirements of dairy cows in different
reduce runoff into the Chesapeake Bay. There are
stages of lactation and determining nitrogen and
currently 556 Master Volunteers who donated over
phosphorus requirements of striped bass. In
30,000 hours in Maryland in 1999 (8).
addition to research, the Animal Nutrient

Management Program faculty educates the public on
Because phosphorus runoff from agricultural
improving animal diet formulation and nutrient
fields has become a high priority, the current
utilization and animal management techniques.
research in the Agronomic Nutrient Management

Program is focused on ways to reduce this
Since the greenhouse industry is the second
phosphorus loss. Some of the research projects in
largest agricultural industry in Maryland, the issue
this program include planting field buffer strips to
of reducing nutrients is a priority. To address this
reduce phosphorus runoff and determining the
issue, researchers in the Nutrient Management for
phosphorus leaching potential from manure. In
Nursery and Greenhouse Industry Program, are
order to determine what the potential of phosphorus
studying the development of cost effective, low-
runoff is from a particular agronomic field, soil
impact nutrient and irrigation strategies. The 3
scientists at the University of Maryland have worked
major research projects in this program include (1) a
with the Agronomic Nutrient Management Program
2-year study determining the nitrogen and
to develop the Phosphorus Site Index (PSI). The
phosphorus uptake and leaching potential of
PSI is a process which rates the potential of
container-grown woody perennial species (holly and
phosphorus to move off of a field and into a water
azalea) using a sprinkler and drip irrigation system
body. This index is based on numerical values and
(2) a study involving monitoring substrate moisture
indicates whether the potential risk for phosphorus
status and cyclic irrigation control in a soilless
movement is low, medium, high, or very high. To
substrate (3) a study in which the economics of
help advisors quickly calculate the PSI, the Nutrient
various nutrient management strategies for container
Management Software Laboratory at the University
systems are determined. A cross-disciplinary team
of Maryland has developed the PSI software
in this program also developed a World Wide Web
program. This software is a Windows-based
based class entitled "Water and Nutrient
program that includes soil mapping unit information
Management Planning for the Nursery and
for each county in Maryland, soil leaching potential
Greenhouse Industry". Attendees of this class have
and watershed information. The Software Lab is
included growers, consultants and MCE and MDA
also in the process of developing a new program
professionals. In 2000, the class won several
entitled "Nutrient Management for Maryland"
national awards including the Outstanding
(NuMan MD). This Windows-based program
Professional Skill Award and the Gold Medal
allows the advisors to make nutrient
Award from Agricultural Communicators in
recommendations based on updated information,
Education (7).
and will replace the existing FERTREC program.

The updated features of NuMan MD include
In the Turfgrass Nutrient Management Program,
updated fertility recommendations for all crops to
faculty members evaluate various kinds of turfgrass
meet Maryland nutrient management requirements,
(as many as 800) every year in order to generate up
fertility recommendations for an additional 30-40
to date nutrient recommendations, which are used by
crops, direct uploading and insertion of soil test file
golf course operations, turf farms, lawn care
information, and the ability to insert information
companies, governmental properties and parklands.
from existing FERTREC files.
These nutrient recommendations are published

biannually as a fact sheet entitled "Turfgrass
CONCLUSION
Cultivar Recommendations for Certified Sod and

Professional Seed Mixtures in Maryland".
Because the Chesapeake Bay is the United States'

largest estuary, maintaining its water quality is a top
In the Urban Nutrient Management Program, the
priority. Government officials have designed
focus is on reducing soil erosion and runoff from
policies such as the WQIA and the Chesapeake Bay
urban landscapes and appropriately fertilizing lawns
Agreement to provide guidance to the people of
and gardens. MCE staff are responsible for training
Maryland on reducing nutrient pollution going into
Master Gardener volunteers who in turn educate
the Chesapeake Bay. From these policies, important
homeowners about ways they can reduce fertilizer
programs have developed such as the Tributary
and pesticide use on their lawns, thus helping to
Strategies Program, the MNMP, the MACS Program

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and the Manure/Poultry Litter Transport Programs.
In addition to these programs, the University of
Maryland faculty is continuously conducting
research to provide farmers, industries and private
landowners with solutions to help reduce nutrients
going into the Bay while at the same time
maintaining the profitability of the farming
enterprise. The combined efforts of everyone in the
state is the key to achieving the 40 percent reduction
goal and having the Chesapeake Bay removed from
the federal list of impaired waters by the year 2010.

References

(1) Chesapeake Bay Program. 2000. Where are We and
Where are We Going? Chesapeake Bay Program Fact Sheet
(http://www.chesapeakebay.net/pubs/snapc2k.pdf).
Chesapeake Bay Program, Annapolis, MD 21403 USA.

(2) Chesapeake Bay Program. 1999. The State of the
Chesapeake Bay - A Report to the Citizens of the Bay
Region
(http://www.chesapeakebay.net/pubs/sob/chapter2.pdf).
Chesapeake Bay Program, Annapolis, MD 21403 USA.

(3) University of Maryland, College of Agriculture and
Natural Resources. 1998-2000. Nutrient Management Annual
Reports.

(4) University of Maryland, College of Agriculture and
Natural Resources. 1998-2000. Nutrient Management Annual
Reports.

(5) Maryland Department of Agriculture. 2000. Maryland's
Manure Transport Project Brochure.

(6) Maryland Department of Agriculture. 2000. Maryland's
Poultry Litter Transport Project Brochure.

(7) University of Maryland, College of Agriculture and
Natural Resources. 2000. Nutrient Management Annual
Report. p. 5.

(8) University of Maryland, College of Agriculture and
Natural Resources. 2000. Nutrient Management Annual
Report. p. 7.

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