“Nitrogen Stabilizer Product Evaluations”

Paxton W. FittsTimothy W. WalkerDelta R&E Center

Contributors

• Dustin Harrell – LSU• Rick Norman – U of A• Nathan Slaton – U of A• Trenton Roberts – U of A• Jac Varco – MSU• Bobby Golden – MSU• David Franzen – NDSU• Jay Goos ‐ NDSU

Urea’s Reaction ProducesNH3 Gas

2 NH3  ammonia gas on soil surfaceor in flood

‐ H2O & CO2

CO(NH2)2 (NH4)2CO3 2 NH4+  + 2 OH‐

urea urease (pH ~ alkaline) ammonium salt in soil

Note: Urea’s reaction in soil initially is alkaline and increases soil pH causing                      ammonia volatilization loss if not incorporated in soil quickly.

Slide borrowed from R. Norman

Nitrogen Fertilizer Stabilizers/Additives

• NZONE/STAY‐N/N‐STAY• Ca‐Aminoethylpiperazine and Ca‐

Heterpolysaccharides• “N management aid” “reduce 

nutrient loss” “maintain N levels”

• NutriSphere‐N® – 40% maleic‐itaconic co‐polymer

• “Polymer stabilizes and protects urea‐N, inhibiting volatilization and nitrification”

• Upgrade – Perploxylated phenol polymer resin mix

• “Slow release polymer blend agent”

• Agrotain®/Arborite/N‐FIXX– N‐(n‐butyl) thiophosphorictriamide, Urease inhibitor, “stabilizes N” “blocks urease” “reduces NH3 volatilization”

Ammonia Volatilization

0

2

4

6

8

10

12

0 5 10 15 20

% of a

pplied

Days

NH3 Volatilization Loss

urea

ams

agrotain

Data from Tunica clay.  Dillon and Walker, unpublished

Rice Research Station – fertility and Agronomy ProjectWalker et al., unpublished data

0

5

10

15

20

25

30

0 5 10 15 20 25 30

NH3 lost (%

 of N

 app

lied)

Days

clay urea

clay agrotain

clay arborite

clay stay‐N

silt loam urea

silt loam agrotain

silt loam arborite

silt loam stay‐N

Lab Volatilization

Nitrogen Stabilizers/Additives

• NutriSphere‐N® –40% maleic‐itaconicco‐polymer

• “Polymer stabilizes and protects urea‐N, inhibiting volatilization and nitrification”

Lab EvaluationNutrisphere

0816243240485664

0 5 10 15

Cumulative NH3Loss 

(% of a

pplied N‐fe

rtilizer)

Time (days)

Urea Agrotain+Urea Nutrisphere+Urea Ammonium Sulfate

Source: Franzen et al. (2011, in press) J. Plant Nutr.0.25% Nutrisphere added

• Perploxylated phenol polymer resin mix

• “Slow release polymer blend agent”

• “Reduces urea dissolution”

• “Reduces the potential for volatilization over the competition and untreated urea from 25 to 50% at 3‐4 qt/ton”

Lab EvaluationUpgrade

051015202530354045

0 5 10 15

Cumulative NH3Loss 

(% of a

pplied N‐fe

rtilizer)

Time (days)

Urea Agrotain‐Urea Upgrade‐Urea

Source: Norman and Roberts (unpublished data) 

Lab EvaluationExtend

051015202530354045

0 5 10 15

Cumulative NH3Loss 

(% of a

pplied N‐fe

rtilizer)

Time (days)

Urea Agrotain‐Urea Extend‐Urea

Source: Norman and Roberts (unpublished data) 

Rice Research Station – fertility and Agronomy ProjectWalker et al., unpublished data

0

5

10

15

20

25

30

0 5 10 15 20 25 30

NH3 lost (%

 of N

 app

lied)

Days

silt loam urea

silt loam agrotain

silt loam arborite

silt loam stay‐N

Lab Volatilization

Rice Research Station – fertility and Agronomy ProjectWalker et al., unpublished data

Lab Volatilization

0

5

10

15

20

25

30

0 3 7 10 14 17 21

%NH3 loss

Days

Urea

Agrotain Ultra 3qt

N‐FIXX 3 qt

Rice Research Station – fertility and Agronomy Project

0

5

10

15

20

25

3 6 9 12 15 18 21

NH4‐N lo

ss (%

 of t

otal 

applied)

Time (days)

UreaAS‐UreaASSuper‐UAgrotain‐Urea

Data provided by Dr. Dustin Harrell

Rice Research Station – fertility and Agronomy Project

i

e-h d-h

a

a-d a-da-e a-c

5000

5500

6000

6500

7000

7500

8000

8500

9000

9500

10 DPF 7 DPF 4 DPF 1 DPF

Yie

ld (l

b/A

)

Application time (Days Prior to Flooding)

UreaAgrotain-Urea

581 lbs7 %

1238 lbs15 %

Nitrogen Cycle

Urea is quickly broken down in the soil into NH3

(NH2)2CO2 + H2O → 2NH3 + CO2

NH3 undergoes further degradation

Ammonium (NH4+)  Nitrite (NO2

‐)

Nitrate (NO3‐)Volatile N2 loss

Nitrosomonas

Nitrobacter

Reduction

0123456789

5.1 5.3

8.5 8.7

4.77.0

5.3

Ammonium Half‐life (days)

Fitts and Walker, 2011.  Unpublished.

Grain Yield

LSD = 7Source x Timing (P = 0.0024)8218

8071

8235

7467

7642

7000

7200

7400

7600

7800

8000

8200

8400

43% Urea ENTEC

lb/A 2DBF

10DBF

LSD = 421

Data collected at DREC2010

Sharkey clay soil

Urea vs Agrium 43%

5453

7233

4273

5602

6859

5289

0

1000

2000

3000

4000

5000

6000

7000

8000

14 1

lb/acre

Days before flood

Urea 150Urea 75Agrium 150Agrium 75

LSD = 394

Special Thanks