Advances in Fertilizer

Technologies for Improved

Nutrient Management

University of Delaware

Greg Binford, Ph.D.Associate Professor & Extension Specialist

302-831-2146 or binfordg@udel.edu

Enhanced-Efficiency Fertilizers

Products designed to improve the nutrient-use

efficiency when using fertilizers.

In other words, the goal is to get more nutrient into the

crop and less lost to the environment.

Understanding N Loss Potential

1) Three ways that N is lost from soils to the environment

2) Nitrate form of N lost thru leaching & denitrification

3) Ammonium form of N lost via volatilization

- leaching, denitrification, & volatilization

Enhanced-Efficiency N Fertilizers

1) Slow release through “Coatings”

2) Slow-release through chemical formulation

3) Inhibition of processes: urease & nitrification

4) IMPORTANT: Data should demonstrate that the mode

of action does work

Slow-Release N Fertilizers

1) Polymer-coated urea product: ESN

2) Chemical control: urea formaldehyde/methylene urea

- Nitamin, CoRon, Nutralene, Nitroform

- release controlled by chain length of molecules

3) Sulfur-coated urea: used primarily in turf

4) Organic N fertilizers: mineralization of N

Agrotain®, also known as NBPT, which is:

N-(n-butyl) thiophosphoric triamide

(registered product of Agrotain International in

St. Louis, MO)

Temporarily blocks the function of urease enzyme

Provides a “window” of time for rain to move the urea

molecule down into the soil

Nitrapyrin: N-SERVE® and INSTINCT®

(registered products of Dow AgroSciences)

Temporarily blocks the process of nitrification

NH4+ + 2O2 => NO3

- + H2O + 2H+X X

DCD (dicyandiamide): Guardian®

Urease AND Nitrification Inhibitors

1) Agrotain Plus: Agrotain + DCD for UAN

2) Super U: dry urea product (Agrotain + DCD)

3) Nutrisphere-N: maleic-itaconic copolymer that

“combines with Ni to decrease urease activity and

combines with Fe and Cu to decrease microorganism

metabolic activity delaying nitrification”

4) N Zone: Calcium Aminoethylpiperazine and Calcium

Heteropolysaccharides that “react with ammonia

carbonate changing it to calcium carbonate.”

Ammonia Losses: AGROTAIN

0

10

20

30

40

50

60

0 5 10 15 20

Cu

mu

lative

Am

mo

nia

Lo

ss

(%)

Days After Treatment

Urea

UAN

Urea+NBPT

UAN+NBPT

UAN+AgroPlus

Source: Dr. W. Thornberry, Sturgis, KY; Dr. S. Ebelhar, Univ of Illinois

Laboratory incubation

High Volatilization Potential

0

50

100

150

200

250

0 50 100 150 200

Urea Urea w/ Agrotain Super U

RATE OF N APPLIED (lb N/acre)

CO

RN

GR

AIN

YIE

LD

(b

u/a

c)

Applied June 1

Four days w/o rain

Temp: 74, 88, 81, 65

Rain on day 5 = 1.6”

Corn

Gra

in Y

ield

(b

u/a

c)

Corn

Gra

in Y

ield

(b

u/a

c)

0

10

20

30

40

50

60

1 2 3

None N Serve

Effect of N Serve on NitrificationA

mm

on

ium

-N (

pp

m)

Three Sites in KansasMaddux et al., 1985 (SSSAJ)

150 lb N/acre as spring-applied NH3

Minnesota: N-Serve 1999

0

20

40

60

80

100

120

140

160

180

200

NH3 fall NH3 spring

109

187

154178

w/o N-serve w/ N-Serve

Co

rn G

rain

Yie

ld (

bu

/ac)

Randall and Vetsch

0

5

10

15

20

25

30

35

40

45

UAN UAN w/ DCD Anhydrous

Effect of DCD on Nitrate Leaching

Type of N Sidedressed on Corn

Nit

rate

Lea

ched

(lb

N/a

c)

Motavalli et al., 2008 (Review)

Averaged fall nitrate leaching losses over three growing seasons in Canada

Tiessen et al., 2006 (AJ)

Nitrification with Super U

Urea =>

Super U =>

Tiessen et al., 2006 (AJ)

Nitrification with Super U

Urea =>

Super U =>

ESN preplant vs UAN sidedress

90

100

110

120

130

140

150

160

170

180

190

1 2 3 4 5 6 7 8 9 Mean

ESNpp UAN sdd

Nine Sites in Delaware from 2004 through 2008

Corn

Gra

in Y

ield

(b

u/a

c)

161

148

ESN vs Urea BOTH preplant

50

70

90

110

130

150

170

1 2 3 4 5 6 7 8 9 Mean

ESN Urea

Nine Sites in Delaware from 2004 through 2009

Corn

Gra

in Y

ield

(b

u/a

c)

151

120

SANDY SOILS

Ammonia Volatilization: AT/NSN

0

10

20

30

40

50

60

70

0 3 7 11 15

21-0-0-24 Urea Urea +AT Urea +NSN

Dr. Rick Norman, Univ. of Arkansas

DAYS SINCE APPLICATION OF UREA FERTILIZER

NIT

RO

GE

N V

OL

AT

ILIZ

ED

(%

)

Ammonia Volatilization: AT/NSN

0

5

10

15

20

25

30

35

40

45

1 3 5 7 10 14

Bare Soil Urea Urea +AT Urea +NSN

Dr. Elizabeth Guertal

Auburn University

DAYS SINCE APPLICATION OF UREA FERTILIZER

NIT

RO

GE

N V

OL

AT

ILIZ

ED

(%

)

Ammonia Volatilization: NSN

0

5

10

15

20

25

30

35

40

45

50

2 4 6 9 12 16

Urea Urea +NSN

Dr. R. Jay Goos

North Dakota State University

DAYS SINCE APPLICATION OF UREA FERTILIZER

NIT

RO

GE

N V

OL

AT

ILIZ

ED

(%

)

Effect on Nitrification

(14-day incubation)

0

10

20

30

40

50

60

70

80

90

100

Urea Agrotain NSN Super U

NH4

NO3

Rec

ov

ery o

f N

Ap

pli

ed (

%)

Rick Norman, Univ. of Arkansas

0

50

100

150

200

250

300

350

Week 1 Week 2 Week 3 Week 4

Urea-NH4 Urea-NO3 NSN-NH4 NSN-NO3

Effect on Nitrification

(4-week incubation)

Nit

rate

or

Am

mo

niu

m (

pp

mN

)

Dr. R. Jay Goos

North Dakota State University

Urease AND Nitrification Inhibitors

1) Agrotain Plus: Agrotain + DCD for UAN

2) Super U: dry urea product (Agrotain + DCD)

3) Nutrisphere-N: maleic-itaconic copolymer that

“combines with Ni to decrease urease activity and

combines with Fe and Cu to decrease microorganism

metabolic activity delaying nitrification”

4) N Zone: Calcium Aminoethylpiperazine and Calcium

Heteropolysaccharides that “react with ammonia

carbonate changing it to calcium carbonate.”

Criteria for EE Fertilizers

1) Know the mode of action

2) Determine where greatest value should be obtained

3) Consider the rate of nitrogen applied?

4) Data that demonstrates the mode of action

5) Evaluate cost-to-benefit with on-farm trials

6) Remember that the product will only provide increased

value when conditions exist that induce losses of nitrogen

7) Value of enhanced efficiency fertilizers increases as

nitrogen fertilizer prices increase

0

100

200

300

400

500

600

700

800

900

Urea UAN ESN Super U UAN ATP Check

Rate of N2O Emissions

TYPE OF N APPLIED

Tota

l N

2O

Evolv

ed (

g N

/ha)

Halvorson et al., 2010 (JEQ)

Averaged over two growing season (2007 & 2008)

AVAIL: Early Growth Response

0

20

40

60

80

100

120

140

160

180

259 181 274 197 28 32 24 288 Mean

w/o Avail w/ Avail

Earl

y G

row

th (

% o

f C

on

trol)

Soil Test P Concentration at SEVEN Study Locations in 2007 & 2008 (FIV)

AVAIL: Corn Grain Yield

0

50

100

150

200

250

259 181 274 197 28 32 24 288 Mean

w/o Avail w/ Avail

Corn

Grain

Yie

ld (

bu

/acre

)

Soil Test P Concentration at SEVEN Study Locations in 2007 & 2008 (FIV)

Site BS -- 2009

0

50

100

150

200

250

5 10 20 30 Mean

w/o Avail w/Avail

Rate of P Applied in Starter Band with 25 lb N (lb P2O5/ac)

Earl

y G

row

th (

% o

f C

on

trol)

STP = Low

Site BS -- 2009

0.0

0.5

1.0

1.5

2.0

2.5

5 10 20 30 Mean

w/o Avail w/Avail

Rate of P Applied in Starter Band with 25 lb N (lb P2O5/ac)

Ph

osp

horu

s U

pta

ke

at

V6 (

lb P

2O

5/a

cre

)

STP = Low

Site BS -- 2009

150

160

170

180

190

200

210

0 5 10 20 30 Mean

w/o Avail w/Avail

Rate of P Applied in Starter Band with 25 lb N (lb P2O5/ac)

Grain

Yie

ld (

bu

/acre

)

STP = Low

25 l

b N

only

Contr

ol

CONCLUSIONSAgrotain clearly reduces ammonia volatilization when

conditions exist for volatilization

Agrotain Plus, Super U, N-Serve, and Instinct* reduce N

loss potential in wet conditions

Nutrisphere-N data suggest not much impact on

volatilization or nitrification

There is NO product that should be recommended on all

soils, under all conditions, and provides season-long

control of nitrogen losses!

ESN is a slow-release product that reduces N loss potential

QUESTIONS???Greg Binford @302-831-2146 or binfordg@udel.edu