Implementation of a
Progressive Manure
Application Management
(ARM) System to Protect
Watersheds from Agricultural
Runoff and Leaching Events
Nichole Embertson, Ph.D.
Whatcom Conservation District
Waste to Worth, Seattle, WA
April 2, 2015
Protecting Puget Sound Watersheds from Agricultural Pollution Using a
Progressive Manure Application Risk Management (ARM) System
A method of assessing and
mitigating the runoff and leaching
risk associated with manure
application on a temporal (timing)
and spatial (location) scale year-
round.N. Embertson, S. Cox, C. Clark, and G.
Boggs
4 R’s of Nutrient Management
4 R’s Nutrient Management
(NRCS)
Right Time
Right Rate
Right Source
Right Placement
Application Risk Management
You want to apply, so what should you do?
1. Determine agronomic rate
2. Identify optimal fields (field risk map)
3. Determine current conditions:
o Manure Spreading Advisory (MSA)
o Seasonal Manure Setbacks
4. Assess field and fill out ARM Worksheet
5. Apply and monitor fields
Do this assessment year round!
Identify Low Risk Fields
Runoff Risk Rating
(October-June)
Leaching Risk Rating
(June-October)
Manure
Spreading
Advisory Real-time
Auto-update from
NOAA
Runoff risk
Soil leaching risk
layer May 2015
~100 pageviews per
month
www.whatcomcd.org/M
SA
Runoff Risk Ratings (Jan-May)
ARM
WorksheetFill out
Worksheet
Forecast
Field Conditions
Protective Measures
Send to WCD
Runoff Risk by
field and day
Recordkeeping &
accountability
ARM Worksheet Parameters
Precipitation 24 h
Precipitation 72 h
Soil type
Soil moisture
Water table depth
Forage density
Forage height
Field surface
condition
Manure application
equipment
Waterbody adjacent
Application setback
Buffer width
Risk Rating
Nutrient Management Plan
Guidance
https://sites.google.com/site/wadairypla
n
ARM Field Measurements
Provide field data to:
Better understand nutrient cycling
Determine risk level of fields
Tune risk values/thresholds in
Worksheet
Validate MSA
Data collection to be completed: April
2015
Final report: August 2015
Site Characteristic
6 paired 5 acre plots
All plots in grass/forage production
2 treatments:
CON = Conventional application
timing
ARM = Application Risk
Management
2 Soil types:
Silt Sandy loam (4 plots) – Deep,
well drained, low runoff, not
saturated
Silt loam (2 plots) – Deep, poorly
Field Testing Parameters
Surface Water: FC, NO3, NH4, P, Temp,
pH
Soil Water: NO3, NH4, TN, TP, pH
Groundwater: NO3, NH4, TN, TP, Cl
Soil: NO3, NH4, TN, TP, pH, OM, Cond,
temp, moisture
Forage: NO3, N, P, K, yield, height, density
Manure: NO3, NH4, TN, TP, pH, rate
Meteorological: Precip, temp
Management: Application, irrigation,
Field Evaluation Setup
Forage Yield
- Yield was 10-40% greater when early season (Jan) application was made (sand).
- Yield increase was due to forage density (25%↑), not height.
- Silt had delayed response in yield.
- Late fall application on silt lead to greater spring yield.
0.00
0.50
1.00
1.50
2.00
2.50
Spring - Sand Spring - Silt Summer -Sand
Summer - Silt Fall - Sand Fall Silt
Yie
ld (
ton
.acre
)
p<0.05
CON
ARM
Soil Phosphorous
0
50
100
150
200
250
300
350
400
450
500
10
/6/2
011
11
/6/2
011
12
/6/2
011
1/6
/20
12
2/6
/20
12
3/6
/20
12
4/6
/20
12
5/6
/20
12
6/6
/20
12
7/6
/20
12
8/6
/20
12
9/6
/20
12
10
/6/2
012
11
/6/2
012
12
/6/2
012
1/6
/20
13
2/6
/20
13
3/6
/20
13
4/6
/20
13
5/6
/20
13
6/6
/20
13
7/6
/20
13
8/6
/20
13
9/6
/20
13
10
/6/2
013
11
/6/2
013
12
/6/2
013
1/6
/20
14
2/6
/20
14
3/6
/20
14
4/6
/20
14
5/6
/20
14
6/6
/20
14
7/6
/20
14
8/6
/20
14
9/6
/20
14
10
/6/2
014
11
/6/2
014
12
/6/2
014
1/6
/20
15
2/6
/20
15
P1 (
Bra
y)
(mg
/kg
)
CON12
CON24
CON36
ARM12
ARM24
ARM36
Soil Nitrate
Nitrate trended with soil temperature (dashed
line)
Late application (October) on sandy soil
yielded higher fall/winter nitrate levels
Groundwater Nitrate
Surface Runoff
- Surface
grab
samples
- Manure
application
setbacks
prevented
manure
runoff into
stream
- No
correlation
between FC
and NH4-N,
NO3, P, or
TN
Manure Application
Event
General Conclusions
Nitrate leaching in the fall/winter is determined by nitrogen application in the fall (Sept-Oct)
Irrigation can push N/nitrate in soil profile in summer
Runoff is a factor for rain events on limiting (saturated) soils in spring
Soil type has big influence on runoff and leaching potential/magnitude
Manure N conversion/availability varies throughout the year and challenges 4Rs
ARM Outcomes
Develop customized manure application
strategies for farms
Optimize manure application timing by soil
type to minimize losses
Create real-time management tools to help
make nutrient management decisions
Number of dairies in Whatcom with full ARM
plan : 35% (~12,200 acres)
Questions?
Nichole M. Embertson, Ph.D.Nutrient Management and Air Quality Specialist
Whatcom Conservation DistrictO: (360) 526-2381 x 126
Disclaimer: The reproduction or use of any of the images or content within this document is not allowed without prior approval from the creator.