Transcript Nitrogen Reduction Strategies - Conservation Districts of Iowa

IOWA NUTRIENT REDUCTION STRATEGY
A science and technology-based framework to
assess and reduce nutrients to Iowa waters and
the Gulf of Mexico
Spring 2013
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Why? And Why Now?
• Society expects higher environmental actions
from cities, industry and agriculture
• Gulf Hypoxia Task Force requires plan to
reduce N and P load to Gulf by 45% by 2013
• EPA requests strategy that emphasizes state
implementation of new and existing N and P
practices for point and non-point sources
• Pending lawsuit to force EPA to adopt nutrient
standards for 31 states of Mississippi River
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Nutrient Reductions Needed to Meet
Gulf of Mexico Hypoxia Goal
Nutrient Reductions
• 45% reduction of nitrogen to Gulf
• 45% reduction of phosphorus to Gulf
Statewide strategy by 2013 for achieving
reductions
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Nutrient delivery to the Gulf of Mexico
State shares of the total nutrient flux
Nitrogen
Alexander et al,
Environ. Sci. Techn., in press
Phosphorus
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Science Assessment
For nonpoint source landscapes, to achieve
45% N & P reductions identify
– what practices needed
– what level of practice adoption
– what targeted locations for practices
– what estimated costs
– what resource assistance and programs are
needed
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Nutrient Reduction Strategy – Science Team
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Matt Helmers – ISU – N Team Lead
Tom Isenhart – ISU – P Team Lead
John Lawrence – ISU
John Sawyer – ISU
Antonio Mallarino – ISU
William Crumpton – ISU
Rick Cruse – ISU
Mike Duffy – ISU
Reid Christianson – ISU
Phil Gassman – ISU
Dean Lemke – IDALS
Shawn Richmond – IDALS
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Jim Baker – IDALS/ISU
Keith Schilling – IDNR
Calvin Wolter – IDNR
Dan Jaynes – USDA-ARS
Mark Tomer – USDA-ARS
John Kovar – USDA-ARS
David James – USDA-ARS
Eric Hurley – USDA-NRCS
Mark David – Univ. of Illinois
Gyles Randall – Univ. of Mn
Katie Flahive - USEPA
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Science Assessment
• Establish baseline – existing conditions
– Major Land Resource Areas used to aggregate conditions
• Extensive literature review to assess potential
performance of practices
– Outside peer review of science team documents (practice
performance and baseline conditions)
• Estimate potential load reductions of implementing
nutrient reduction practices (scenarios)
– “Full implementation” and “Combined” scenarios
• Estimate cost of implementation and cost per pound
of nitrogen and phosphorus reduction
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Nitrogen or Phosphorus?
Nitrogen moves primarily as
nitrate-N with water
Phosphorus moves primarily
with eroded soil
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Reaching the 45% goal
• Point sources achieve maximum biological
removal rate: 4% N and 16% P
• Nonpoint source goal becomes 41% N
and 29% P to achieve 45% goal for Iowa
• Requires high adoption of full suite of
practices to reach the goal
– Not simple
– Not impossible
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Nitrogen Reduction Practices
Practice
Timing (Fall to spring)
Source (Liquid swine
Nitrogen
compared to commercial)
Management
Nitrogen Application Rate
Nitrapyrin (N Serve)
Cover Crops (Rye)
Perennial – Land retirement
Land Use
Living Mulches
Extended Rotations
Drainage Water Mgmt.
Shallow Drainage
Edge-of-Field
Wetlands
Bioreactors
Buffers
% Nitrate-N Reduction
[Average (Std. Dev.)]
6 (25)
4 (11)
Depends on starting point
9 (19)
31 (29)
85 (9)
41 (16)
42 (12)
33 (32)*
32 (15)*
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43 (21)
91 (20)**
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Phosphorus Reduction Practices
% Phosphorus-P Reduction
[Average (Std. Dev.)]
Practice
Producer does not apply
phosphorus until STP drops to
optimal level
Source (Liquid swine
Phosphorus
compared to commercial)
Management
Incorporation
No-till (70% residue) vs.
conventional tillage (30%
residue)
Land Use
Edge-of-Field
17 (40)
46 (45)
36 (27)
90 (17)
Cover Crops (Rye)
29 (37)
Perennial – Land retirement
75 (-)
Pasture
59 (42)
Buffers
58 (32)
Phosphorus assessment does not include
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stream bed and bank contribution
Summary of Example Scenarios
Name
Initial
Investment
(million $)
Statewide
Total EAC* Cost Average EAC
(million $/year) Costs ($/acre)
NCS1
3,218
756
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NCS3
1,222
1,214
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NCS8
4,041
77
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Agricultural Nonpoint Sources
• Nutrient impairment is not mainly due to
mismanagement of fertilizers and
manures, but more to historic changes in
land use and hydrology
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Agricultural Nonpoint Sources
• Nutrient impairment is not mainly due to
mismanagement of fertilizers and
manures, but more to historic changes in
land use and hydrology
• It is unlikely that in-stream phosphorus
loading WQ goals will be achieved from
only in-field P loading reductions to
streams, given in-channel bed and bank
erosion and resulting P loads
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What’s New?
• Nonpoint and point sources integrated
plan & working together towards goal
• Nonpoint source science assessment
• Harness the collective initiative of Iowa ag
organizations, ag business & farmers
• Major cities (102) and industries (46) treat
to remove nutrients
• Coordination through water resources
coordinating council (WRCC)
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Goal – Iowa Leader
“As Iowa is a national and global leader in
the production of food and renewable fuels,
a goal of this strategy is to make Iowa an
equal national and global leader in
addressing the environmental and
conservation needs associated with food
and renewable fuels production.”
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Iowa Strategy Approach –
Nonpoint Sources
• Achieve nutrient load reductions through
voluntary technology-based actions, while
• Continuing to assess and evaluate nutrient
water quality standards
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22 Nonpoint Source Actions
In 8 Categories
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Watershed prioritization & goals
Setting priorities
Research & technology
Strengthen outreach, education, collaboration
Increased public awareness & recognition
Funding
Accountability & verification measures
Public reporting
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Strategy Implementation
• 12 of 22 nonpoint source action items are
underway now through WRCC & agencies
• ISU Extension Outreach 2012-13
– Integrated Crop Management Conference –
1000 CCA’s
– Pesticide & manure applicator training, Crop
Advantage Series meetings – 26,000 farmers
• Ag landowners, farmers encouraged to
evaluate practices, continue adoption
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Why is Strategy Important?
• Based on sound science in Iowa, for Iowa
• Meaningful and measureable progress
• Builds on current programs and targeted
watersheds
• Utilizes the policy framework which will
provide greatest progress and success
• Improves water quality in Iowa and Gulf of
Mexico
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www.nutrientstrategy.iastate.edu
Iowa Department of Agriculture and Land Stewardship
www.IowaAgriculture.gov
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