Transcript Managing P & N Nutrient Resources

Managing P & N Nutrient
Resources
Agronomy In-service
January 3, 2013
Greg LaBarge, Field Specialist, Agronomic Systems
Discussion
• Why be concerned with nutrient/sediment
• Phosphorus
– What do we want farmers to do
– Tri-state Philosophy and Status
• Nitrogen
– Economic rate calculator
• Other Issues
Why be concerned about
nutrients/sedimentation leaving edge of field?
• Water Quality Concerns in water bodies
– EPA water quality measured as “intended use”
– Regulation
• Ohio Ag Pollution Abatement
from “manure and sediment
bound nutrients” to “nutrients”
– Sedimentation removal
• Cost Maumee and Harbor
($5,000,000 annual)
• Good Stewards
and Public Pressure
• Economic Cost (Loss) of Nutrients
Value of Nutrient In Maumee River
• Average value of nutrient lost WY20082011
– based on $650 per ton P2O5 & $0.65 cent
Nitrogen
Nutrient
Phosphorous
Nitrogen (Nitrate)
Value
$ 4,129,291
$39,694,230
Total
Per acre
$43,823,521
$13.52
Phosphorus
•
•
•
•
•
Soil reactions of phosphorous
Nutrient Movement
What do we want farmers to do
Do the tri-state recommendations still work
Recommendation resources
Three Important Soil P Fraction for
Plant Nutrition
Soil Solution
Labile P
Nonlabile P
Nutrient Movement
Manure
Fertilizer
Plant uptake
Adsorbed
P
Labile P
Adsorption
Desorption
Solution P
Secondary
Minerals
Fe/AlPO4
CaHPO4
Nonlabile P
Precipitation
Dissolution
H2PO4HPO42<0.3 ppm
Mineralization
Immobilization
Organic
Matter
Bound
P
Nonlabile P
Labile P
Primary
Minerals
Nonlabile P
Dissolution
Leaching
Leaching
Total P in soil – 50-1500 ppm
~ 100-3000 lb/acre
Water Definitions
• Total Phosphorus
"Total" phosphorus is largely defined on the basis of how much
phosphorus in its various forms will be oxidized into
orthophosphate by a specific oxidant.
• Water soluble P
–Dissolved reactive phosphorus (DRP)
–Bioavailable Phosphorus
The soluble form of the nutrient phosphorus, which is readily
available for use by plants. consist largely of the inorganic
orthophosphate (PO4) form of phosphorus.
• Particulate P
Soil attached P
Source: Heidelberg University
Maumee River Gauging Station
Source: Hiedelberg University
Increased DRP?
• Increased broadcast applications
– Time required for nutrient to attach to sites
– Stratification and preferential flow
• No-till
• Time needed to re-establish preferential flow after tillage
• Soil tests levels
– STL are in decline & P fertilizer sales are declining
• Tile increased intensity
• Rotation changes
• Size of farm
Nutrient Movement
• Can they move?
– Yes. Largest deciding factors are soil texture and nutrient
concentration (tillage is a factor as well, obviously)
Boem et al., SSSAJ, 2008
Nutrient Movement
• Nutrient concentration causing nutrient leaching
1.5
Drainage from 50-cm undisturbed soil lysimeters
1
Dissolved P,
mg/L
0.5
0
0
200
400
600
Mehlich-3 soil P, mg/kg
800
Discussions agricultural reductions
• Five month public
process
• 100 plus individuals
involved
• Final report
• http://www.dnr.state.oh.
us/portals/12/docs/water
qualityreport.pdf
What contribution to reduction can
agriculture make?
• 4R Nutrient Stewardship
– ‘Right’ Rate, ‘Right’ Timing, ‘Right’ Placement &
‘Right’ Source
• Industry Developed Program
– Global
– http://www.nutrientstewardship.com/
• Goals
– Increase crop production & improve profitability
– Minimize nutrient loss & maintain soil fertility
– Ensure sustainable agriculture for generations to
come
Additional In-service
For More Information: https://www.agronomy.org/
Recommendations to Reduce Nutrient
Movement off -site
• The ‘Right’ Rate.
– Good representative soil sample should be the basis
for fertilizer application.
– Utilize Ohio State University Extension Agronomic
Recommendations for nutrient application.
– Records should be kept for all soil tests,
recommendations and applications as well as crop
and resulting yields.
– http://agcrops.osu.edu/specialists/fertility/fertility-factsheets-and-bulletins
Source: Ohio Director’s Working Group on Ag Nutrients 4/12
Fertility Rates
Critical Level
• “…the soil test level above which the soil
can supply adequate quantities of a
nutrient to support optimum economic
growth.”
• Below the CL”…the soil is not able to
provide P and K requirements of the crop.”
• Above the CL”…the soil is capable of
supplying the nutrient required by the crop
and no response to fertilizer would be
expected.”
Critical Level
Crop
P- Bray 1
(PPM)
P- Bray 1
(lbs/A)
Corn & Soybeans
15
30
Wheat & Alfalfa
25
50
Spatial Variation
Soil test P
0-15
7/20/2015
15-30
30-45
45-60
60-75
75-90
90-105
105-120
120-135
21
Nutrient Distribution
• Mean soil test P – 18 ppm
• Median soil test P – 16 ppm
22
7/20/2015
Maintenance Plateau Range
• “Designed to replace nutrient lost each
year through crop removal.”
• “…no response to fertilizer in the year of
application expected.”
• “No response to placement technique
such as banding or stripping or the use of
P and K starter fertilizer…”
Corn
Maintenance Limit
Crop
P- Bray 1
(PPM)
P- Bray 1
(lbs/A)
Corn & Soybeans
30
60
Wheat & Alfalfa
40
80
Drawdown
• “When soil test levels exceed maintenance
plateau level (Maintenance Limit), the
objective of the fertilizer recommendation
is to utilize residual soil nutrients….There
is no agronomic reason to apply fertilizer
when soil test are above the maintenance
plateau level.”
Drawdown
Crop
P- Bray 1
(PPM)
P- Bray 1
(lbs/A)
Corn & Soybeans
40
80
Wheat & Alfalfa
50
100
Corn
"What do you mean do not put any P on,
won't my soil test drop?"
Two part answer.
First yes, soil test levels will drop, but if you
are above the crop response range for the
crop it really is not a problem crop production
wise. If you are above 30 PPM there is no yield
benefit and if you are way above this level
there is an economic benefit to using this soil
stored P.
"What do you mean do not put any P on,
won't my soil test drop?“ Part 2
The second part of the answer is soil test do
not drop 1 to 1 with crop removal. A 150
bushel corn crop removes (150 bushel * 0.37
Crop removal = 56 lbs). Phosphorous
chemistry in the soil buffers the crop removal
so that for each 15-20 lbs of P2O5 removal
phosphorous levels in the soil are lowered 1
PPM. So our 150 bushel crop will lower the
soil test at around 3-4 PPM.
Expected Soil Test Changes
• The buildup equations in the Tri-states
• 20 lbs./A of P2O5 to change soil test P
levels one ppm.
• 6 to 10 lbs./A of K2O are required to
change soil test 1 ppm depending upon
the soil CEC.
Equations
BUILDUP EQUATION
for P: lb P2O5/A to apply = [(CL - STL) x 5] (YP x CR)
MAINTENANCE EQUATION
for P: lb P2O5/A to apply = YP x CR
DRAWDOWN EQUATION
for P: lb P2O5/A to apply = (YP x CR) - [(YP x CR) x (STL - CL 15))/10]
CL = critical soil test level (ppm)
STL = existing soil test level (ppm)
YP = crop yield potential (bu per acre for grains, tons per acre for forages)
CR = nutrient removed per unit yield (lb/unit)
CEC = soil cation exchange capacity (meq/100g)
Recommendation Resources
Recent looks at Tri-state Critical Values
• 1993-1999. Dr. Jay Johnson study at
Western Branch relative yield without
fertilizer
• 2006-present. Dr. Robert Mullen study at
Western, Northwest and Wooster fertilizer
at 0, 1X, 2X rate based on tri-state
Critical Levels
Relative yield, % of max
• Ohio State data – relative corn yield and STP
110
100
Critical Value –
30 lb/ac
90
80
70
60
50
0
20
40
Soil test P, lb/acre
60
80
Critical Levels
Relative yield, % of max
• Ohio State data – relative soybean yield and STP
140
120
100
80
Critical Value –
30 lb/ac
60
40
20
0
0
20
40
Soil test P, lb/acre
60
80
Iowa
Are Current Critical Levels Still
Valid?
• Northwest Research Station near Custar, Ohio
• Initial soil test levels
– P – 39 ppm; K – 272 ppm; CEC – 24 meq/100 g
– Critical levels – 15 ppm (P) and 135 ppm (K)
• Would you expect much response at this location?
Are Current Critical Levels Still
Valid?
• Phosphorus response in corn-soybean rotation
Chart 6. Phosphorous Response in Corn-Soybean Rotation at
North West Research Station, Custer, OH
180
160
140
Bu/A
120
100
80
60
40
20
0
2006
0
1X
2007
2X
2008
2009
Year
2010
2011
Soil test level P= 39 PPM
Are Current Critical Levels Still
Valid?
• Phosphorus response in corn-corn-soybean rotation
Chart 5. Phosphorous Response in Corn-Corn-Soybean Rotation at
North West Research Station, Custer, OH
180
160
140
Bu/A
120
100
80
60
40
20
0
2006
0
1X
2007
2X
2008
2009
Year
2010
2011
Soil test level P= 39 PPM
Are Current Critical Levels Still
Valid?
• Western Research Station near Springfield, Ohio
• Initial soil test levels
– P – 20 ppm; K – 102 ppm; CEC – 14 meq/100 g
– Critical levels – 15 ppm (P) and 110 ppm (K)
• Would you expect much response at this location?
Are Current Critical Levels Still
Valid?
• Phosphorus response in corn-soybean rotation
Chart 4. Phosphorous Response in Corn-Soybean Rotation
at Western Research Station, South Charleston, OH
300
*
250
*
*
Bu/A
200
150
100
50
0
2006
0
1X
2007
2X
2008
2009
Year
2010
2011
Soil test level P= 20 PPM
Are Current Critical Levels Still
Valid?
• Phosphorus response in corn-corn-soybean rotation
Chart 3. Phosphorous Response in Corn-Corn-Soybean
Rotation at Western Research Station, South Charleston,
OH
250
*
*
200
150
Bu/A
*
100
50
0
2006
0
1X
2007
2X
2008
2009
Year
2010
2011
Soil test level P= 20 PPM
Are Current Critical Levels Still
Valid?
• East Badger Farm near Wooster, OH
• Initial soil test levels
– P – 17 ppm; K – 109 ppm; CEC – 11 meq/100 g
– Critical levels – 15 ppm (P) and 103 ppm (K)
• Would you expect much response at this location?
Are Current Critical Levels Still
Valid?
• Phosphorus response in corn-soybean rotation
Chart 2. Phosphorous Response in Corn-Soybean Rotation at
East Badger Farm, Wooster
250
200
**
**
Bu/A
150
100
50
0
2006
0
1X
2007
2X
2008
2009
Year
2010
2011
Soil test level P= 17 PPM
Are Current Critical Levels Still
Valid?
• Phosphorus response in corn-corn-soybean rotation
Chart 1. Phosphorous Response in Corn-Corn-Soybean Rotation at
East Badger Farm, Wooster
250
*
200
*
Bu/A
150
100
50
0
2006
0
1X
2007
2X
2008
2009
Year
2010
2011
Soil test level P= 17 PPM
Other Rate Considerations
• Product Margin vs Service
• Consider all nutrient sources
Other Rate Considerations
• Precision
Application
– Sampling scheme
– Variable rate
across field
• Goal
• Even levels across
field-good for pH
• Application rate
based on crop
response
Other Rate Considerations
• Rented vs Owned
– Fertility Levels
– Structures
Recommendations to Reduce Nutrient
Movement off -site
• The ‘Right’ Time.
– Nutrients should not be applied to frozen or
snow covered ground.
– Nutrients should be applied as close to crop
utilization as possible.
– Or if not applied close to utilization practices
should be used to keep it in forms that limit
movement offsite
Source: Ohio Director’s Working Group on Ag Nutrients 4/12
Recommendations to Reduce Nutrient
Movement off -site
• The ‘Right’ Place.
– Phosphorous applications should be injected
or incorporated whenever possible.
– If surface applications are made, it should
have a growing crop or cover as soon as
possible.
Source: Ohio Director’s Working Group on Ag Nutrients 4/12
Rainfall simulator study, NW Ohio, Nov 2009
Dissolved P, ppm
16
14
Control
12
DAP
10
Poultry litter
8
6
4
2
0
Tilled-incorporated
Tilled-surface
No-till cover
• P sources applied at 80 lb P2O5 per acre
• Total P loss < 2% of amount applied
• Rain @ 2.4”/hour; first 30 minutes runoff
Mullen, 2011, unpublished
No-till
Placement
•
•
•
•
•
Row Starter
Foliar
Strip Tillage
Other banded application
Incorporation
Recommendations to Reduce Nutrient
Movement off -site
• In addition to the 4 R’s- Improve Soil
Quality.
– Soil organic matter.
– Soil compaction.
– Water infiltration rates.
– Methods to reduce runoff.
Source: http://leopold.iastate.edu
Source: Ohio Director’s Working Group on Ag Nutrients 4/12
Tiling
Blind Inlets
Contribution
Recommendations to Reduce Nutrient
Movement off-site
• In addition to the 4 R’s- Improve Water Management and
Possible Treatment of Drainage Water.
– Repair broken subsurface drainage.
– Treating surface inlets runoff into subsurface drainage
systems.
– Treating concentrated surface runoff areas.
– Controlled drainage.
– Constructed wetlands for treatment
– Improved designed filtered areas, biofilters
– Alternative drainage ditch designs
Source: Ohio Director’s Working Group on Ag Nutrients 4/12
Nitrogen Recommendations
Nitrogen Recommendations
Relationship between yield level and
agronomic optimum N rate in Ohio (90 sites –
corn after soybeans)
7/20/2015
62
Nitrogen Recommendations
So…
Land Grant Universities (in the Midwest) have
moved away from yield goal based
recommendations as a result of this information
What are we left with?
It’s a risk model, what is the risk of a certain N rate with
regard to agronomic performance while considering the
economic factors
7/20/2015
63
Nitrogen Recommendations
Where we are today with new recommendations
Where I think we should go?
Using the above template, evaluate different sources,
timings, and methods of N application to define risk of
yield loss at various N rates
Lots of data yet to be collected
7/20/2015
64
Economic Nitrogen Rate Calculators
• Mullen Developed
http://agcrops.osu.edu/specialists/fertility/f
ertility-fact-sheets-and-bulletins Will be
updated by 3/1/2013
• Iowa State (houses midwest verson)
http://extension.agron.iastate.edu/soilfertilit
y/nrate.aspx
Iowa Site
Other Issues
• NRCS 590 Nutrient Management and 633
Manure Nutrients was combined into one
590 standard
• NRCS CAPS (Conservation Activity Plan)
– 102 Comprehensive Nutrient Management
Plan
– 104 Nutrient Management Plan
– Systems Soil testing, precision application,
cover crops, controlled traffic, strip tillage
http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/programs/t
echnical/tsp/
Summary
• Building case for better nutrient
management-economic and environmental
• Tri-state Philosophy
– Tri-state P & K Recommendations are sound
• What do we want farmers to do:
– 4R Nutrient Stewardship
• Introduction to Nitrogen
– This is an area we need to more in moving
forward. Economic implications are greater.