Performance of Nitrogen Stabilizers in Manure and Fertilizer Tom Morris University of Connecticut 860-486-0637 [email protected] Iowa Soybean Association On-Farm Network® Conference Ames, Iowa, Feb 23, 2010

N stabilizers • Data from companies that sell •

stabilizers show an increase in yield on average – 9 bushels is often cited On-Farm Network data from 2009 suggests no benefit in Iowa for corn

• Why?

Outline • Forms of N in soil • Materials used to stabilize N • Which form, timing and placement of • •

N have greatest potential for benefit from stabilizers Research results from around US on N stabilizers On-Farm Network results from strip trials

N is the tricky element • • • • •

Has many 3 major forms Some forms easily lost from field Others not easily lost Factors not in our control, (rainfall, temp, soil type) affect the forms lost from field Factors in our control, (timing of N, type of N, placement) can reduce losses

Form of N affects gains and losses of N 3 major forms of N in soil: - organic N (not easily lost) - ammonium N (not easily lost; stays on soil particles) - nitrate N (easily lost; moves with water)

Organic N • Soil organic matter (5% organic N) • Plant residues • Manures

Organic N • Not easily lost; stays put • Need microorganisms to convert to •

ammonium N 1.5% to 4.0% of organic N in soil organic matter converted to ammonium every season

How much organic N converted to ammonium N? Soil with 3% organic matter: • 1.5% of organic N converted = 45 lbs of ammonium-N/acre • 4.0% of organic N converted = 120 lbs of ammonium-N/acre

• More ammonium produced if soil has manure history or legume history

Ammonium N • Not easily lost • Attaches strongly to clay in soil • Is converted quickly to nitrate in warm moist soils (nitrification)

• Above 50 degrees fast conversion •

(days) Below 50 degrees, slow (weeksmonths)

Nitrate N • Easily lost; moves with water • Leaches from soil with water • Is lost to atmosphere when •

converted to N gas if soil is saturated with water (denitrification) Plants mostly uptake nitrate N

How N is lost from soils • Leaching: nitrate moving thru soil • Denitrification: nitrate escaping as •

gas to atmosphere when soil saturated Volatilization: N is lost to atmosphere as ammonia gas from urea fertilizer, ammonium fertilizer or manure

N processes in soils • Nitrification is the conversion of •

ammonium to nitrate by bacteria when soil is warm and moist Urea fertilizer and urea in manures is converted to ammonia by urease enzyme

N stabilizers • Nitrification inhibitors O O O

N-serve (Nitrapyrin) Instinct (Encapsulated nitrapyrin) DCD (Dicyandiamide)

• Urease inhibitors O

Agrotain

• Controlled release urea O

Poly coated urea (ESN)

Why use stabilizers? More efficient use of N

• Slow conversion of ammonium to • •

nitrate (nitrification inhibitors) Slow conversion of urea to ammonia (urease inhibitors) Physically protect urea (ESN)

Nitrification inhibitors • Delay the conversion of ammonium • • • •

to nitrate Reduce the chance for loss of nitrate N-Serve used with fall applications of anhydrous ammonia Instinct used with manures and UAN DCD used with Agrotain (a urease inhibitor)

Ammonium-N (ppm)

Effect of N Serve on Nitrification

Maddux et al., 1985 (SSSAJ)

150 lb N/acre as spring-applied NH3

Three Sites in Kansas

Iowa: N-Serve 1985-1987 Each bar is average of 18 sites

Corn Grain Yield (bu/ac)

Ammonium sulfate in spring

Cerrato and Blackmer, 1990

Only 2 of 72 comparisons were significant

Corn Grain Yield (bu/ac)

Minnesota: N-Serve 1999

Randall and Vetsch

Urease inhibitors • Urease enzyme converts urea to • • •

ammonia, which is a N gas Urease inhibitors slow the conversion of urea to ammonia If conversion occurs in soil, ammonia gas goes to ammonium If conversion occurs on soil surface, can be lost to atmosphere

Urease inhibitors • Argotain (NBPT) • Impregnated onto urea • Tank mixed with UAN

NITROGEN VOLATILIZED (%)

Ammonia volatilization More wind = greater loss Rain < 0.5 inch = greater loss Broadcast greater loss than band pH > 7.0 = greater loss More residue = greater loss

DAYS SINCE APPLICATION OF UREA FERTILIZER Overdahl et al., 1987

Corn Grain Yield (bu/acre)

PA Study (Fox & Piekielek, 1993) 140

PREPLANT UREA without (-) & with (+) Agrotain

130 120

116

119

UREA+

34-0-0

110 100

97

90

UREA3-year study

TYPE OF NITROGEN TREATMENT Avg. 100 + 150

Nitrification and urease inhibitors • Argotain with DCD is Agrotain plus O

Used with UAN

• Super U is urea formed with Agrotain •

plus Nutrisphere (NSN)

CORN GRAIN YIELD (bu/ac)

Delaware -- 2009 Applied June 1 Four days w/o rain Temp: 74, 88, 81, 65 Rain on day 5 = 1.6”

RATE OF N APPLIED (lb N/acre)

NutriSphere N (NSN) • A maleic-itaconic calcium salt co-polymer • Urease inhibitor: Theory is NSN inhibits urease when impregnated on urea by tying up nickel (Ni) ions in the soil rendering the urease enzyme (which contains Ni in its structure) inactive • Nitrification inhibitor: Theory behind NSN’s nitrification inhibiting abilities is the complex of copper by NSN; copper needed for nitrification

NITROGEN VOLATILIZED (%)

Ammonia Volatilization: AT/NSN Dr. Rick Norman, Univ. of Arkansas

DAYS SINCE APPLICATION OF UREA FERTILIZER

NITROGEN VOLATILIZED (%)

Ammonia Volatilization: NSN

Dr. R. Jay Goos North Dakota State University

DAYS SINCE APPLICATION OF UREA FERTILIZER

Nitrate or Ammonium (ppm N)

NSN Effect on Nitrification (4-week incubation)

Dr. R. Jay Goos North Dakota State University

Recovery of N Applied (%)

Stabilizer Effect on Nitrification (14-day incubation)

Rick Norman, Univ. of Arkansas

Poly coated urea • ESN “environmentally smart N” • Slow-release N based on polymer • • • •

break down Volatilization not a concern Sidedress N better than ESN (Del) Surface application slower release than incorporated Apply earlier than normal if no-till

ESN technology

ESN preplant vs UAN sidedress Corn Grain Yield (bu/ac)

Greg Binford, U. Delware

161 148

Nine Sites in Delaware from 2004 through 2008

ESN vs Urea Both preplant Corn Grain Yield (bu/ac)

Greg Binford, U. Delware

SANDY SOILS 151

120

Nine Sites in Delaware from 2004 through 2009

Urease inhibitor

Nitrification inhibitors Greatest benefit - Fall anhydrous, if warm fall (N-serve) - Fall manure, if warm (Instinct)

Lower benefit - Spring manure, if warm, rainy (Instinct) - Spring UAN, if warm rainy (Instinct)

Urease inhibitors Greatest benefit - Surface applied urea, UAN (Agrotain) - Surface applied chicken manure; N in chicken manure mostly uric acid that converts to urea

Lower benefit - Banded urea or UAN

No benefit - Injected or tilled-in urea, UAN, Chick.

Nitrification and urease inhibitors Greatest benefit - Surface applied urea, UAN (Agrotain plus) - Surface applied chicken manure; N in chicken manure mostly uric acid that converts to urea

Lower benefit - Banded urea or UAN

No benefit - Injected or tilled-in urea, UAN, Chick.

On-Farm Network results

On-Farm Evaluations of NutriSphere-N with Sideressed UAN on Corn in 2009 Rainfall, in Yield Trial ID

Soybeans Corn (3) Soybeans Soybeans Corn (5) Soybeans Soybeans Soybeans

Average

UAN Rate

lb N/acre 125 50 75 140 80 125 125 65

Spring

June

July

UAN with UAN NutriSphere-N

Yield Diff

bu/acre 9.86 7.94 7.99 11.51 14.15 8.36 8.32 10.89 9.9

2.77 3.80 3.17 3.05 4.84 4.08 4.03 4.60 3.8

2.76 4.74 4.00 4.40 1.55 2.11 2.28 2.65 3.1

All sites injected as sidedress

183.2 150.5 217.0 188.5 174.4 170.7 159.5 171.5 177

184.4 149.5 218.1 182.9 174.5 173.2 162.2 170.2 177

-1.2 1.0 -1.1 5.6 -0.1 -2.5 -2.7 1.3 0.0

Stalk Values – 8 NutriSphere N Trials 100%

80%

60% Excessive Optimal Marginal 40%

Deficient

20%

0% UAN

UAN+NutriSphere

On-Farm Evaluations of Agrotain Plus with Sidedressed UAN Corn Rainfall, in Previous Additional N Crop

Corn (5) Corn (3) Soybeans Corn (3) 104, Sw. Man. Soybeans Soybeans 22, DAP, Fall Corn (5) 75, UAN, Plant Soybeans75, UAN, Plant Corn (5) 75, UAN, Plant Soybeans75, UAN, Plant Corn (4) Average

Time of UAN

Side Side Side Plant Side Side Side Side Side Side Side

UAN Rate

Yield

Yield Total N Agrot Rate Sp June July ain UAN Diff Plus

lb N/acre 175 175 142 142 125 125 70 174 140 140 125 147 50 125 50 125 50 125 50 125 147 147

bu/acre 10.2 11.0 9.9 10.8 11.5 8.4 10.9 10.9 10.9 10.9 13.2 10.8

All sites injected as sidedress

3.9 4.7 2.8 2.6 3.1 4.1 4.6 4.6 4.6 4.6 3.7 3.9

3.8 3.1 2.8 5.4 4.4 2.1 2.7 2.7 2.7 2.7 4.3 3.3

200 207 183 185 184 167 154 165 167 168 199 180

201 210 184 185 183 172 158 167 170 166 199 181

-1.1 -3.0 -0.2 -0.3 1.3 -4.9 -3.2 -2.0 -2.2 1.9 -0.5 -1.3

Stalk Values – 11 UAN Agrotain Plus Trials with UAN sidedressed 100%

80%

60% Excessive Optimal Marginal

40%

Deficient

20%

0% UAN

UAN+Agrotain

On-Farm Evaluations of InstinctTM with Spring-Applied UAN Corn Time of UAN Previous Additional N UAN rate Crop Soybeans Soybeans Soybeans 31, DAP, Fall Soybeans 31, DAP, Fall Corn (7) Soybeans Alfalfa 100, NH3, SD Corn (3) 125, NH3, Fall Corn (3) 240, Dairy,SP Corn (3) 240, Dairy,SP Corn (3) 240, Dairy.,SP Corn (4) 90, Sw., SP Corn (4) 180, NH3, Fall Corn (4) 130, UAN, SD Soybeans 140, Sw. Fall

Spring Spring Spring Spring Split Split Spring Spring Spring Spring Spring Spring Spring Spring Spring

140 100 125 125 185 133 45 50 35 35 35 70 30 30 30

Incorporated in most fields

Rainfall Sp

June

14.8 14.8 8.1 8.1 8.2 7.6 11.1 11.8 9.8 9.8 9.8 10.8 10.1 10.1 12.9 10.5

inches 4.7 4.7 3.9 3.9 4.5 4.6 2.7 4.6 4.2 4.2 4.2 2.6 2.5 2.7 8.0 4.1

Yield

Yield July Instinct UAN Diff 5.9 5.9 4.2 4.2 5.1 4.7 3.8 2.0 6.1 6.1 6.1 5.4 4.0 3.8 3.3 4.7

256 201 197 203 190 203 87 187 105 203 193 185 187 183 232 187

bu/acre 257 209 199 198 195 204 89 187 103 195 193 184 186 184 232 188

-1.0 -7.6 -2.1 4.3 -5.3 -0.6 -1.9 0.3 2.6 7.7 0.4 1.2 1.3 -1.9 -0.6 -0.2

Stalk Values – 15 InstinctTM Trials with Spring UAN 100%

80%

60% Excessive Optimal Marginal 40%

Deficient

20%

0% UAN

UAN+InstinctTM

On-Farm Evaluations of InstinctTM with Liquid Swine Manure on Corn Manure Previous Crop

Total N Rate

Additional N

Rainfall Sp

lb N/acre

Yield

Jun July

Yield Manure Manure Diff Instinct

inches

bu/acre

Corn (3) beans

108 123

50, UAN, SD

10.1 10.9

4.1 4.4

3.3 3.3

202 196

202 198

0.5 -1.9

beans

165

50, UAN, SD

8.8

4.3

3.6

222

218

3.7

beans beans beans

175 194 156

50, UAN, SD

9.2 9.8 10.0

4.7 4.8 5.1

3.9 6.0 3.3

196 179 143

194 179 145

1.7 0.0 -1.9

beans beans beans

113 163 261

100, UAN, SP

8.8 9.9 12.2

4.3 4.1 4.3

3.6 2.7 2.6

206 232 162

206 234 167

0.1 -2.0 -5.6

Corn (3)

100

75, UAN, SD

10.5

4.3

3.2

182

188

-5.8

75, UAN, SD All injected

8.7 9.9

5.1 4.5

3.2 3.5

155 189

152 189

3.1 -0.7

Corn (12) Fall app

125 exc. last

Stalk Values – 11 InstinctTM Trials with Liquid Swine Manure 100%

80%

Excessive 60% Optimal

Marginal 40% Deficient

20%

0% Manure +InstinctTM

Manure

Instinct, fall LSM 3.7 bu increase

Instinct, fall LSM 5.8 bu decrease

On-Farm Network data different?

• Company data from many locations • • •

in US Expensive to test for all conditions Need to test products and practices for conditions in Iowa 2009 season cooler early

On-Farm Network data different?

• Rainfall in spring and in June and • •

July normal or slightly below normal Corn yield response to N lower than in previous two seasons Some On-Farm Network data not from conditions when N stabilizers have greatest potential for benefit

Summary • Need to know when N stabilizers will •

most likely provide a benefit Not likely profitable in situations with minimal chance for benefit