Nutrient Efficiency: Applying What You Need When You Need It.
Why do we care?
Mark S. Reiter, Ph.D. Nutrient and Soil Management Specialist
Why do we care? Environmentally…
(http://www.netstate.com/states/geography/mapcom/images/va.gif, 2009)
Soil Test P vs. Runoff P
(The Chesapeake Bay Program, 2008)
(Pote et. al., 1996)
1
Four Main Efforts to More Regulatory Control of Agriculture
Environmentally Water quality concerns
Congressional Reauthorization of Chesapeake Bay Senator Cardin’s (D-MD) S. 1816 with hearing November 9, 2009 Representative Cummings (D-MD) H.R. 3852
Eutrophication
President Obama’s Executive Order Executive Order signed May 12, 2009 Draft strategy for public comment released November 9, 2009
EPA Total Maximum Daily Load Plan Development December 14 Public Hearing, Falls Church High School’s Little Theater December 15 Public Hearing, Legacy Hall, Williamsburg, Virginia December 16 Public Hearing, Spotswood High School, Rockingham County December 17 Public Hearing, Wingate Inn, Fredericksburg
Governor Kaine’s Agreement with Bay State Governors on 2 Year Milestones Implemented through Governor’s Proposed Budget, Regulatory Policy Changes Possible, Proposed Legislative Initiatives (Moore, 2009)
(Palmer, 2007)
Why do we care?
What nutrients should I apply? Fertilize if needed
Environmentally… Agronomically…
Yield loss
Focus $ on correct nutrient Do not over-apply Agronomic Environmental
YIELD LOSS (ETT, 2008)
Fertilizer Cost Increase 600
(http://www.nass.usda.gov/Charts_and_Maps/Agricultural_Prices/prod1.asp; USDA-NASS, 2009)
100
Oct-09
Mar-09
Jan-08
Aug-08
Jun-07
Apr-06
Nov-06
Sep-05
Jul-04
Feb-05
Dec-03
Oct-02
May-03
Mar-02
Jan-01
0 Aug-01
Oct-09
Mar-09
Jan-08
Aug-08
Jun-07
Apr-06
Nov-06
Sep-05
Jul-04
Feb-05
Dec-03
Oct-02
May-03
Mar-02
Jan-01
Aug-01
Jun-00
Apr-99
Nov-99
Sep-98
Jul-97
0
200
Jun-00
100
300
Apr-99
200
Nov-99
300
Fertilizer increase of 375% from Aug. 1999 to Aug. 2008
400
Sep-98
400
Fertilizer
500
Jul-97
500
Feb-98
Years 1990-1992 = 100% Index
Fertilizer
Feb-98
Years 1990-1992 = 100% Index
600
Fertilizer Cost Increase
(http://www.nass.usda.gov/Charts_and_Maps/Agricultural_Prices/prod1.asp; USDA-NASS, 2009)
2
Fertilizer Cost Increase 600
100
Oct-09
Mar-09
Jan-08
Aug-08
Jun-07
Apr-06
Nov-06
Sep-05
Jul-04
Feb-05
Dec-03
Oct-02
May-03
Mar-02
Jan-01
Aug-01
0
Oct-09
Mar-09
Jan-08
Aug-08
Jun-07
Apr-06
Nov-06
Sep-05
Jul-04
Feb-05
Dec-03
Oct-02
May-03
Mar-02
Jan-01
Aug-01
Jun-00
Apr-99
Nov-99
Sep-98
Jul-97
0
200
Jun-00
100
300
Apr-99
200
Nov-99
300
224% Lower since August 2008 high
400
Sep-98
Fertilizer increase of 151% from Aug. 1999 to Oct. 2009
400
Fertilizer
500
Jul-97
500
Feb-98
Years 1990-1992 = 100% Index
Fertilizer
Feb-98
Years 1990-1992 = 100% Index
600
Fertilizer Cost Increase
(http://www.nass.usda.gov/Charts_and_Maps/Agricultural_Prices/prod1.asp; USDA-NASS, 2009)
(http://www.nass.usda.gov/Charts_and_Maps/Agricultural_Prices/prod1.asp; USDA-NASS, 2009)
Fertilizer Cost Increase
Crop Uptake and Removal
Years 1990-1992 = 100% Index
600
Fertilizer Crop Value
500
Nitrogen Crop
Crop value increase of 49% from Aug. 1999 to Oct. 2009
400
Yield
Uptake
Removal
P2O5 Uptake
Removal
K2O Uptake
Removal
-----------------------------Pounds per acre-----------------------------Potatoes
350 cwt
188
112
70
53
280
196
Sweet Potatoes
400 bu
103
208
68
52
295
224
Tomatoes
40 tons
232
100
87
68
463
288
Corn
180 bu
240
162
102
79
240
52
Soybeans
40 bu
210
152
38
32
144
56
Wheat
75 bu
175
113
57
45
116
300 200 100
Oct-09
Mar-09
Aug-08
Jan-08
Jun-07
Nov-06
Apr-06
Sep-05
Feb-05
Jul-04
Dec-03
May-03
Oct-02
Mar-02
Aug-01
Jan-01
Jun-00
Nov-99
Apr-99
Sep-98
Jul-97
Feb-98
0
(USDA-NASS, 2009)
http://pubs.ext.vt.edu/446/446-047/446-047.html
26 (IPNI, 2009)
Input Price Increases
3
Input Price Increases
Input Price Increases
N= 20%
43%
Nitrogen
Nitrogen – We must always apply… Numerous loss pathways.
(MSU, 2007)
Nitrogen Agronomically Taken up as nitrate or ammonium by plant Element needed in largest quantity from the soil Component of amino acids
Nitrogen Agronomically Taken up as nitrate or ammonium by plant Element needed in largest quantity from the soil Component of amino acids
4
Nitrogen Transformation
Nitrate Nitrogen Nitrate is common component of fertilizers
Oxygen plus
NH4+
NO3-
bacteria
Nitrification
(IPNI, 2009)
Nitrate Nitrogen
Nitrogen
Nitrate is common component of fertilizers Nitrate primary water pollutant
Nitrate is common component of fertilizers Nitrate primary water pollutant
Highly soluble Mobile
Highly soluble Mobile
-NO - +K 3 Anion leaches easily Clay particle - +Na
-
Anion leaches easily
Makes N difficult to soil test…
+H
Carbon and Nitrogen Equilibrium (10:1; C:N ratio)
Immobilization increased in no-tillage Microbes’ body = 8:1; C:N Corn Stover = 65:1; C:N
Pounds of C and N per acre
Nitrogen in No-Till
16000 14000 12000 10000 8000
Organic C Organic N
6000 4000 2000 0 Year 0
Year 4
Year 8
Year 12
Years after No-till Began (Wood et. al., 1991)
5
14000 12000 10000 8000 6000 4000
Extra Nitrogen Fertilizer Needed!
Organic C Organic N
2000 0
Carbon and Nitrogen Equilibrium (10:1; C:N ratio) Pounds of C and N per acre
16000
16000
Plateau
14000
Nitrogen Fertilizer Use Levels Or Decreases
12000 10000 8000 6000 4000
Organic C Organic N
Plateau
2000 0
Year 0
Year 4
Year 8
Year 12
Year 0
Years after No-till Began
Year 4
Year 8
Year 12
Years after No-till Began (Wood et. al., 1991)
Problems with Nitrogen in No-Tillage Volatilization
(Wood et. al., 1991)
Problems with Nitrogen Volatilization
Important with urea containing fertilizers Liquid urea-ammonium nitrate (UAN; 30% N) Enzymes on crop residue break down urea Problem in no-tillage systems
Important with urea containing fertilizers Liquid urea-ammonium nitrate (UAN; 30% N) Enzymes on crop residue break down urea Problem in no-tillage systems
Problems with Nitrogen Volatilization Important with urea containing fertilizers
GAS
Pounds of C and N per acre
Carbon and Nitrogen Equilibrium (10:1; C:N ratio)
Liquid urea-ammonium nitrate (UAN; 30% N) Enzymes on crop residue break down urea Problem in no-tillage systems
Increase Efficiency Reduce nitrogen contact with residue because of urease Place the nitrogen under the crop residue Reduce losses from: Microbes Volatilization
(USDA-NRCS, 2009)
6
Nitrogen Efficiency - Timing
Nitrogen Timing
Plant 15-30 lb N/A Fall
First split Count tillers 0-60 lb N/A
Second split Tissue test 0-120 lb N/A
Harvest
Late Winter
Spring
Summer
(Alley et. al., 1996)
BREAK TIME!
Boron Deficiency “Clear window” and curled leaves Leaches in sandy soils
Boron Deficiency
BREAK TIME!
The Fix: Foliar feed Pre-plant blend. Based on soil test.
(Gehl, 2007; Reiter 2008)
7
Manganese Deficiencies Immobile nutrient
Manganese Deficiency The Fix:
Top of plants in new leaf growth
Foliar feed Pre-plant blend.
Interveinal chlorosis Veins remain green
Based on soil test.
Can lighten if severe
High soil pH
(Gehl, 2007; Reiter 2008)
Back to Nitrogen in Wheat… Kansas Study 60 bu./acre Following corn and soybeans Used liquid UAN (28% N) Silt loam soil ~25 in. rain
80 Total N Uptake (lbs N/Ac)
Winter wheat
Kansas Study Average Total N Uptake
70 60 50 40 30
52 lbs N/Ac 0% incr. Std. Practice
57 lbs N/Ac 10% incr.
67 lbs N/Ac 30% incr.
Broadcast
Surface Band
Subsurface Band
20 10 0
(Kelley and Sweeney, 2007)
What would this mean in Maryland OR Virginia? ~230,000 acres of winter wheat per state Average of 120 lbs N/Ac applied 30% nitrogen fertilizer use reduction: 8.4 million pounds fertilizer reduced per state $3.5 million saved per state
(Kelley and Sweeney, 2007)
Application Method
Virginia Field Study Fertilizer Source Liquid UAN 30% N 50% N as ammonium nitrate-N Nitrate is highly mobile = leaching potential
50% N as urea-N Susceptible to losses via volatilization
At $250/ton UAN-30% = $0.42/lb. N $15 per acre in today’s prices $30 per acre in August 2008 prices…
8
Virginia Field Study Treatment Structure Experimental Factors Nitrogen application methods
Treatment Structure Experimental Factors Nitrogen application methods
Broadcast
Surface banding
Standard practice used in Virginia
15-inch 30-inch
(TeeJet, 2009)
Treatment Structure Experimental Factors Nitrogen application methods
Treatment Structure Experimental Factors Nitrogen rates 40, 80, 120, and 160 lbs. N/ac. 0-N control included
Subsurface banding 15-inch 30-inch
Replicated 4 times Split nitrogen Plant 30 lb N/A Fall (Scharf and Lory, 2006)
WARNING: THIS IS ONLY 1 YEAR OF DATA! Results May Vary…
First split GS25 50% N
Second split GS30 50% N
Harvest
Late Winter
Spring
Summer
Test Locations Brandon Plantation Continuously farmed since 1614 Prince George County, VA Pamunkey loam Virginia state soil ~45% sand
9
Brandon Yield by N Rate
Lodging
70
Yield (bu/A)
*Averaged across application methods
67.3a
65 64.5ab 60
61.0b
55
62.1b
56.0c
50 0
40
80
120
160
Spring Nitrogen Rate (lbs/A)
Brandon Biomass by N Rate
Brandon Yield by Application Method 75 *Averaged across N rates
8500 8333ab
8000
8489a
7715b
7500 7000
8499a
7015c
Yield (bu/A)
*Averaged across application methods
70
70.0a
65 60
6500
55
6000
50
62.4b
62.3b
62.5b
53.8c 0
40
80
120
160
Broadcast 15 Dribble 15 Inject 30 Dribble 30 Inject
Spring Nitrogen Rate (lbs/A)
Application Method
Brandon Biomass by Application Method
Subsurface Band – 30 inch 9000
Biomass (lbs/A)
Biomass (lbs/A)
9000
*Averaged across N rates
8500 8000
8373 a
8335 a
8222 a 7865 ab
7500 7000
7256 b
6500 6000 Broadcast 15 Dribble 15 Inject 30 Dribble 30 Inject
Application Method
10
Test Locations
Virginia Eastern Shore
Virginia Tech Eastern Shore AREC
Results mirrored Brandon data. Subsurface banding showing promising results in corn, potatoes, etc.
Accomack County, VA Bojac sandy loam ~65% sand
Virginia Wheat Study Conclusions
Don’t Guess – Soil Test! Determines plant extractable nutrients Free – For Virginia Commercial Farmers
Current nitrogen rates are still adequate. Possibly can be reduced? Reached no-tillage equilibrium?
$16 for Non-VA Sample
Nitrogen surface banding deserves more study.
Accuracy of your sample is paramount!
Soil Tests Results Eastern Shore of Virginia
Change in Soil Test Phosphorus – Control Plots
Need Fertilizer (L and M)
No Fertilizer (H and VH)
Potassium Need Fertilizer (L and M)
No Fertilizer (H and VH)
----------------------------% of samples taken----------------------------Accomack County
9
91
71
29
Northampton Country
3
97
64
36 (Virginia Tech, 2008)
Soil Test Phosphorus (ppm)
80 Phosphorus
70 60
71 ppm
50 40 30
74 ppm
457 lbs P Removed/acre Corn-Soybean-Wheat Rotation
20 10 0 2000
2002
2004 Year
2006
2008
11
Phosphorus Likely little benefit to P application for high or very high soil test readings. Soil has a large P bank. “Draw down” will take a long time. Put your money somewhere else!
(www.msucares.com, 2009)
Potassium
Potassium Soil test for best recommendations. Can we “bank” potassium?
Soil test for best recommendations. Can we “bank” potassium?
Yes - +K +K Clay particle - +Mg
Potassium
Soil Tests Results
Soil test for best recommendations. Can we “bank” potassium? Yes
Lime Likely Need Lime pH below 6.0
Deeper?
Optimal pH Range 6.0 to 7.0
High pH Problems pH above 7.0
-----------------------% of samples taken--------------------------
- +K +K Clay particle - +Mg
- +K Clay particle + - Al - +Ca - +Mg
+K
Accomack County
36
58
6
Northampton Country
31
52
17 (Virginia Tech, 2008)
12
Efficient Fertilizer Use
Take Home Message Pay attention to nitrogen application method, application timing, and rate. Soil test (and follow the recommendations).
Accomack County
QUESTIONS?
Phosphorus Soil Test Summaries Soil Test Level (% of samples)
70
757-414-0724 ext. 16
[email protected]
R² = 0.2916
60 50 40
P Low P Medium
R² = 0.4634
30
P High 20
P Very High R² = 0.1733
10
R² = 0.3002 0 1990
1995
2000
2005
2010
Year
Brandon Lodging by Application Method
Eastern Shore Yield by Nitrogen Rate*
45
60
35 30
31ab 28bc
25 20 15 10
56.4a
*Averaged across N rates
42a
Yield (bu/A)
Lodging (%)
40
14d
Application Method
55.2a
40 30
17cd
Broadcast 15 Dribble 15 Inject 30 Dribble 30 Inject
49.1b
50
55.4a
49.5b
20.8c 20 0
Fall-30 40 80 120 Spring N Rate (lbs/Acre)
160
*Averaged across N application method
13
Eastern Shore Biomass by Nitrogen Rate*
Eastern Shore Yield by Application Method* 70
5727a
6000
6066a
5754a
4953b
5000
4380c
4000 3000
2334d Fall-30 40 80 120 Spring Nitrogen Rate (lbs/A)
60.3a
60
59.1a
57.3a
50.8b
49.1b
50
43.1c
40 30 20
2000 0
Yield (bu/A)
Biomass (lb/A)
7000
20.8d
160
*Averaged across N application method
*Averaged across N rates
Eastern Shore Biomass by Application Method* Biomass (lb/A)
7000 6192a 6210a
6201a
6000 5000
4380b
4641b
4881b
4000 3000
2334c
2000
*Averaged across N rates
14