Nutrient Efficiency: Applying What You Need When You Need It. Why do we care? Why do we care? Soil Test P vs. Runoff P

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 ...
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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