Quirine M. Ketterings, Joe Lawrence, Jon Klapwyk, Michele Wang, Quirine M. Ketterings, Joe Lawrence, Jon Klapwyk, Michele Wang, Miriam Goler, Karl CzymmekMiriam Goler, Karl Czymmek

Nutrient Management Spear ProgramNutrient Management Spear ProgramDepartment of Animal Science, Cornell UniversityDepartment of Animal Science, Cornell University

Fine-Tuning Corn Nitrogen ManagementFine-Tuning Corn Nitrogen Management

Cornell corn N recommendations are based on:

- Yield potential- soil type and drainage

- Soil N supply- soil type and drainage

- N fertilizer uptake efficiency- soil type and drainage

- N credits from sods- % legume/grass in the sod

- N credits from manure- application method + timing

Cornell Corn N Recommendations

(yield potential * 1.2) – soil N – sod N(yield potential * 1.2) – soil N – sod N N requirement = N requirement =

(fertilizer efficiency/100)(fertilizer efficiency/100)in lbs N/acre

in lbs N/acre

in %

in bushels/acre

= soil series specific

Cornell Corn N Recommendations

- soybean N or manure N credits- soybean N or manure N credits

Humid Northeastern Region

0

20

40

60

80

100

120

140

Planting2001

Harvest2001

Planting2002

Harvest2002

Planting2003

Harvest2003

Planting2004

Nitr

ate

N (l

bs N

/acr

e)

Starter only (20 lbs N/acre) Starter + 100 lbs N/acre sidedress

Starter + 150 lbs N/acre sidedress Starter + 200 lbs N/acre sidedress

12 inch soil cores to when corn is 6-12 inches tall.

Pre-Sidedress Nitrate Test (PSNT)Pre-Sidedress Nitrate Test (PSNT)

Pre-Sidedress Nitrate Test (PSNT)Pre-Sidedress Nitrate Test (PSNT)

You really have to want to do this….

It can add to the work overload! Impractical timing for dairy farms.

Pre-Sidedress Nitrate Test (PSNT)Pre-Sidedress Nitrate Test (PSNT)

And there are many opportunities to make mistakes.

Pre-sidedress Nitrate TestPre-sidedress Nitrate Test

Test Method Test Method (Kahn et al., 2001)(Kahn et al., 2001)

• 1 g soil + 10 mL of 2M NaOH in mason jar.1 g soil + 10 mL of 2M NaOH in mason jar.• Add 5 mL of 4% boric acid to suspended petri dish.Add 5 mL of 4% boric acid to suspended petri dish.• Heat for 5 hours on hotplate griddles.Heat for 5 hours on hotplate griddles.• Titrate with sulfuric acidTitrate with sulfuric acid..

Illinois Soil N Test (ISNT)Illinois Soil N Test (ISNT)

225 ppm

Responsive Non responsive

Illinois Soil Nitrogen Test (ISNT)Illinois Soil Nitrogen Test (ISNT)

Main research questions in NY:Main research questions in NY:

Can this test separate responsiveCan this test separate responsivefrom non-responsive sites in New York?from non-responsive sites in New York?

Can we use regular 8 inch Can we use regular 8 inch cores instead of 12 inch cores?cores instead of 12 inch cores?

Can we sample before planting Can we sample before planting or after harvest?or after harvest?

Can we determine N rates?Can we determine N rates?

No Yes[ ? ] [ ? ]

[ ? ] [ ? ]

[ ? ] [ ? ]

[ ? ] [ ? ]

Illinois Soil Nitrogen Test (ISNT)Illinois Soil Nitrogen Test (ISNT)

Four Project Phases

1. Fine-tuning the laboratory procedure

2. Initial field calibration– 0-8 or 0-12 inch samples?

– Timing of sampling?

3. ISNT and manure N credits

4. ISNT use for corn in rotation

• High degree of day-to-High degree of day-to-day and within-griddle day and within-griddle variability.variability.

Initial Observation:Initial Observation:

Phase 1: Laboratory ProcedurePhase 1: Laboratory Procedure

Phase 1: Laboratory ProcedurePhase 1: Laboratory Procedure

Klapwyk and Ketterings (2005)

• Temperature did not affect N recovery.Temperature did not affect N recovery.• ISNT results increase with temperature.ISNT results increase with temperature.• Enclosing griddles resulted in:Enclosing griddles resulted in:

• Lower ISNT-N.Lower ISNT-N.• Lower CV.Lower CV.

• Similar findings in Illinois led to modifications to Similar findings in Illinois led to modifications to include jar rotation at 1.5 and 3 h in Illinois.include jar rotation at 1.5 and 3 h in Illinois.

• Enclosed griddles at 50.6°C gave results directly Enclosed griddles at 50.6°C gave results directly comparable with Illinois.comparable with Illinois.

Phase 1: Laboratory ProcedurePhase 1: Laboratory Procedure

Four Project Phases

1. Fine-tuning the laboratory procedure

2. Initial field calibration– 0-8 or 0-12 inch samples?

– Timing of sampling?

3. ISNT and manure N credits

4. ISNT use for corn in rotation

Phase 2: Initial Field Calibration2002:• Albers• Barney• Bossard• Carey• Czymmek• Kilcer• T&R Center

2003:• Albers• Barney• Bossard • Czymmek• Degni • Kilcer• T&R Center

2004:• Albers• Barney • Bossard • Czymmek• Degni • Hunter• Kilcer• Miller/Stockin• Miner Institute• Tillapaugh• T&R Center

Collaboration with local extension educatorsCollaboration with local extension educators

Soil Parameters Silage Yield %N N Uptake Milk YieldPSNT *** *** *** ***

OM NS S NS NS

ISNT at planting

0-20 cm S * S NS

0-20 cm, OM ** ** ** **

0-30 cm, OM * ** ** **

ISNT at sidedress

0-20 cm NS * S NS

0-20 cm, OM S * S *

0-30 cm, OM NS * S NS

ISNT at harvest

0-20 cm NS S NS NS

0-20 cm, OM * * * *

0-30 cm, OM * * * *

Klapwyk and Ketterings (2006)

Phase 2: Initial Field Calibration

Conclusions:Conclusions:• 8 inch samples ok8 inch samples ok

• Samples could be Samples could be taken outside taken outside growing seasongrowing season

• Both ISNT and Both ISNT and LOI were needed LOI were needed to predict to predict responsivenessresponsiveness

Phase 2: Initial Field Calibration

y = 126.36 + 4.0944x - 0.0199x 2

r 2 = 0.9851; n = 33

0

50

100

150

200

250

300

350

400

0 20 40 60 80 100 120

Organic matter (g kg-1)

ISN

T-N

(m

g k

g-1)

NONRESPONSIVE

RESPONSIVE

Critical Values

y = 126.36 + 4.0944x - 0.0199x 2

r 2 = 0.9851; n = 33

0

50

100

150

200

250

300

350

400

0 20 40 60 80 100 120

Organic matter (g kg-1)

ISN

T-N

(m

g k

g-1)

NONRESPONSIVE

RESPONSIVE

Critical Values

Loss-on-ignition (g kg-1)

Phase 2: Initial Field Calibration

Four Project Phases

1. Laboratory procedure

2. Initial field calibration– 0-8 or 0-12 inch samples?

– Timing of sampling?

3. ISNT and manure N credits

4. ISNT use for corn in rotation

Phase 3: ISNT and Manure

250

300

350

400

450

-5 0 5 10 15 20 25 30 35 40 45

Days

ISN

T . Manure

No manure

0

10

20

30

40

50

-5 0 5 10 15 20 25 30 35 40 45

Days

NH 4

-N

.

Manure

No manure

0

50

100

150

200

-5 0 5 10 15 20 25 30 35 40 45

Days

NO 3

-N

.

Manure

No manure

***

***

***

****** ***

***

***

*********

***

***

*

*

*

**

NS

NSNSNS

Mic

helle

Wan

g, 2

005

Klapwyk et al. (2006)

Nitrate

Ammonium

ISNT

Phase 3: ISNT and Manure N Credits

ISNT:ISNT:• Part of the soil N poolPart of the soil N pool• Increases with manure and compost additionIncreases with manure and compost addition

• Reflects NHReflects NH44++ peaks after manure application peaks after manure application

So, for assessment of soil N supply potential:So, for assessment of soil N supply potential:• Don’t sample within 5 weeks after manure Don’t sample within 5 weeks after manure

applicationapplication

Four Project Phases

1. Laboratory procedure

2. Initial field calibration– 0-8 or 0-12 inch samples?

– Timing of sampling?

3. ISNT and manure N credits

4. ISNT use for corn in rotation

NYS Corn N Trials (2005 - 2007)

1st yr corn2nd yr corn3rd (+) yr cornAfter soybeans

On-Farm TrialsResearch Station TrialsSod Plow Down Study

Trials made possible through

collaboration with

Cornell Cooperative Extension

1st Year: 162nd Year: 123rd Year: 24th Year: 1After Soybeans: 3Total: 34

Phase 4: ISNT for Corn in Rotation

1st yr corn after sod

• Small starter N• Forget about

sidedress N.• Grass or alfalfa

does not matter.• Late fall versus

spring does not matter.

• Stand needs to be sod, not weeds…

Yield MilkTons/acre at

35% DMlbs per ton

0 21.7 a 3193 a

50 22.2 a 3234 a

100 22.4 a 3214 a

150 22.4 a 3211 a

Phase 4: ISNT for Corn in Rotation

Lawrence et al. (2008)

N sidedress 2005 2006 2007lbs/acre tons/acre tons/acre tons/acre

0 22.3 a 30.0 a 19.0 a

50 22.5 a 31.3 a 19.7 a

100 22.9 a 29.7 a 20.5 a

150 22.3 a 29.8 a 19.9 a

Average 22.5 30.0 19.8

2nd+ yr corn or corn after soybean?

Responsive: 8 sites, Nonresponsive: 10 sites

Phase 4: ISNT for Corn in Rotation

100

150

200

250

300

350

400

450

0 1 2 3 4 5 6 7 8 9 10

LOI (%)

ISN

T (

pp

m)

Correct Incorrect

Overall Accuracy: 83% (15 of 18).

Mean Min Max

ISNT (mg kg-1) 388 294 537LOI (g kg-1) 56 41 75

High Variability

Site A

Phase 4: ISNT for Corn in Rotation

100

150

200

250

300

350

400

450

0 1 2 3 4 5 6 7 8 9 10

LOI (%)

ISN

T (

pp

m)

Correct Incorrect

Overall Accuracy: 83% (15 of 18).

Site B

Phase 4: ISNT for Corn in Rotation

Hail storm 2 hours after sidedressing

100

150

200

250

300

350

400

450

0 1 2 3 4 5 6 7 8 9 10

LOI (%)

ISN

T (

pp

m)

Correct Incorrect

Site C100

105

110115

120

125

130135

140

145

0 30 60 90 120 150

Sidedress N rate (lbs N/acre)

Gra

in Y

ield

(to

ns/a

cre,

35%

DM

)

Phase 4: ISNT for Corn in Rotation

Overall Accuracy: 83% (15 of 18).

100

150

200

250

300

350

400

450

500

0 10 20 30 40 50 60 70 80 90 100

LOI OM (g kg-1)

ISN

T (

mg

kg-1

)nonresponsive

100

150

200

250

300

350

400

450

0 10 20 30 40 50 60 70 80 90 100

LOI (g kg-1)

ISN

T (

mg

kg-1

)

nonresponsive

responsive after corn

responsive after soybeansnonresponsive after soybeans

A

B

First year corn:Correct: 10 sitesIncorrect: 6 sites63% accuracy

2nd+ year corn:Correct: 15 sitesIncorrect: 3 sites83% accuracy

0

50

100

150

200

250

300

350

400

450

500

0 100 200 300 400 500

ISNT (ppm) First year

ISN

T (

pp

m)

Se

co

nd

ye

ar

Measures soil organic N mineralization potential?

Samples taken at PSNT time…

Phase 4: ISNT for Corn in Rotation

ISNT in year 1 versus year 2…

Phase 4: ISNT for Corn in Rotation

0

100

200

300

400

500

600

700

0 1 2 4 6 8

Time (weeks)

ppm

ISNT KCl Nitrate KCl Ammonium

0

100

200

300

400

500

600

700

0 1 2 4 6 8

Time (weeks)

ppm

• Un-amended soil had constant ISNT.

• ISNT follows ammonium release for both roots and shoots.

• Nitrification gives flush of nitrate 4-6 weeks after alfalfa incorporation.

• ISNT does not reflect nitrate N.

A

B

NO3-N

NH4-N

ISNT

Miriam Goler, 2007

100

150

200

250

300

350

400

450

500

0 10 20 30 40 50 60 70 80 90 100

LOI OM (g kg-1)

ISN

T (

mg

kg-1

)nonresponsive

100

150

200

250

300

350

400

450

0 10 20 30 40 50 60 70 80 90 100

LOI (g kg-1)

ISN

T (

mg

kg-1

)

nonresponsive

responsive after corn

responsive after soybeansnonresponsive after soybeans

A

B

First year corn:Correct: 10 sitesIncorrect: 6 sites63% accuracy

2nd+ year corn:Correct: 15 sitesIncorrect: 3 sites83% accuracy

Sod N credits need to be added!!

Conclusions for ISNT

• ISNT is an accurate tool for predicting corn responsiveness (yes or no) to sidedress N in NY for 2nd+ year corn

• Fits well with 3-year sampling protocol for general fertility

However:

• ISNT can capture ammonium release 1 – 5 wk after manure application or sod plowdown

And:

• 1st yr corn does not need N so no need to sample for ISNT

Therefore:

• Avoid sampling within about 5 weeks after manure application, sod/cover crop plowdown or chemical kill

• Add manure N and cover crop N credits

Main research questions:Main research questions:

Can this test separate responsiveCan this test separate responsivefrom non-responsive sites in New York?from non-responsive sites in New York?

Can we use regular 8 inch Can we use regular 8 inch cores instead of 12 inch cores?cores instead of 12 inch cores?

Can we sample before planting Can we sample before planting or after harvest?or after harvest?

Can we determine N rates?Can we determine N rates?

No Yes[ ? ] [ x ]

[ ? ] [ x ]

[ ? ] [ x ]

[ x ] [ ? ]

Illinois Soil Nitrogen TestIllinois Soil Nitrogen Test

Cornell Nutrient Management Spear Program – qmk2@cornell.eduCornell Nutrient Management Spear Program – qmk2@cornell.edu

Fine-Tuning Corn Nitrogen ManagementFine-Tuning Corn Nitrogen Management

Questions?