Nitrous Oxide Emissions Nitrous Oxide Emissions from Soils Receiving a from Soils Receiving a

Combination of Dairy Manure Combination of Dairy Manure and Mineral Nitrogen and Mineral Nitrogen

FertilizerFertilizerCurtis Dell

USDA-ARS-PSWMRUUniversity Park, PA

Nitrous Oxide (NNitrous Oxide (N22O)O)

Approximately 300 times more effective than CO2 as a greenhouse gas

Agriculture is a significant contributor

By-product of both nitrification (aerobic) and denitrification (anaerobic)

Denitrification generally believed to be largest N2O source in soils, but rates vary greatly depending on soil aeration

Manure Management In NE Manure Management In NE USUS

Large number of dairy, poultry, and swine facilities

Limited land base for manure application

Water quality problems resulting from excess P accumulations in soil

Nutrient management planning required in several NE/Chesapeake Bay states

Nutrient Management In NE Nutrient Management In NE USUS

Manure application in excess of plant P requirement discouraged/prohibited in many locations

A larger land base for spreading or costly waste treatment required

Combinations of manure and mineral N fertilizers used more frequently

Manure Applications and NManure Applications and N22O O

EmissionsEmissions Greater potential for N2O production

when manure is fertilizer source because of addition of organic C • Energy source for denitrifying bacteria• Stimulates activity by general microbial

population, depleting O2 supply

Combinations of organic and mineral N fertilizers may have even greater potential for emissions • Organic C from manure and readily

available N from mineral fertilizer

ObjectivesObjectives

Determine if N2O emissions from a corn

field differ when N fertilizer is applied

as NH4NO3, dairy manure,or a

combination of the two.

MethodsMethods

N Source TreatmentsN Source Treatments

N Source TreatmentsN Source TreatmentsAll mineral fertilizer75 kg ha-1 N as NH4NO3: preplant-

incorporated75 kg ha-1 N as NH4NO3: side dress, surface

60 kg ha-1 mineral P: preplant, incorporated

N Source TreatmentsN Source TreatmentsAll mineral fertilizer75 kg ha-1 N as NH4NO3: preplant-

incorporated75 kg ha-1 N as NH4NO3: side dress, surface

60 kg ha-1 mineral P: preplant, incorporated

P-based manure (31 Mg ha-1)

~75 kg ha-1 N as manure: preplant, incorporated

75 kg ha-1 N as NH4NO3: side dress, surface

~60 kg ha-1 P as manure: preplant, incorporated

N Source TreatmentsN Source TreatmentsAll mineral fertilizer75 kg ha-1 N as NH4NO3: preplant-incorporated

75 kg ha-1 N as NH4NO3: side dress, surface60 kg ha-1 mineral P: preplant, incorporated

P-based manure (31 Mg ha-1)

~75 kg ha-1 N as manure: preplant, incorporated75 kg ha-1 N as NH4NO3: side dress, surface~60 kg ha-1 P as manure: preplant, incorporated

N-based manure (62 Mg ha-1)

~150 kg ha-1 N as manure: preplant, incorporated~120 kg ha-1 P as manure: preplant, incorporated

Vented chambersVented chambers

Sampling and AnalysisSampling and Analysis

Additional MeasurementsAdditional Measurements

Gravimetric soil water content

Soil inorganic N (2004 only)

ResultsResults

5/1/03 6/1/03 7/1/03 8/1/03 9/1/03 10/1/03 11/1/03

Dai

ly r

ain

fall

(mm

)

0

20

40

60

80

100

5/1/2004 6/1/2004 7/1/2004 8/1/2004 9/1/2004 10/1/2004 11/1/2004

Dai

ly r

ain

fall

(mm

)

0

20

40

60

80

100

120

2003

2004

RainfallRainfall

Source: Penn State Univ. Dept. of Meteorology

Soil Water ContentSoil Water Content

6/1/03 7/1/03 8/1/03 9/1/03 10/1/03

So

il w

ater

co

nte

nt

(g H

2O g-1

)

0.1

0.2

0.3

0.4

Mineral fertilizerP-based manaure plus side-dress NN-based manure

5/1/04 6/1/04 7/1/04 8/1/04 9/1/04

Soil Nitrate: 2004Soil Nitrate: 2004

5/1/04 6/1/04 7/1/04 8/1/04

So

il n

itra

te (

mg

N k

g-1)

0

20

40

60

80

100

120

140

160

180

Mineral fertilizerP-based manure N-based manure

Manure/fertilizer Side-dress N

NN22O Emissions: 2003O Emissions: 2003

6/1/03 7/1/03 8/1/03 9/1/03 10/1/03

N2O

em

issi

on

s (g

N h

a-1 d

-1)

0

100

200

300

400

500

600

700

800

Mineral fertilizerP-based manureN-based manure

Manure /fertilizer

Side-dress N

*

*

NN22O Emissions: 2004O Emissions: 2004

5/1/04 6/1/04 7/1/04 8/1/04 9/1/04

N2

O e

mis

sio

ns

(g

N h

a-1

d-1

)

0

100

200

300

400

500

600

700

800

Mineral fertilizerP-based manureN-based manure

Manure /fertilizer Side-dress N

**

*

**

Estimated Seasonal NEstimated Seasonal N22O O EmissionsEmissions

kg N ha-1 % of total applied N

% of available N1

2003 Mineral fertilizer 8.6 3.6 a 6.0 2.5 6.0 2.5 P- Based manure 7.21.9 a 2.30.6 5.01.3 N- Based manure 8.11.7 a 1.60.3 4.7 1.0

2004

Mineral fertilizer 1.91.1a 1.30.8 1.30.8 P- Based manure 4.31.9 b 1.70.7 3.01.3 N- Based manure 3.91.2 b 1.00.3 2.70.8

1Assuming 35% of total N is available during the year of application

ConclusionsConclusions

N2O emissions are potentially greater when all or part of the N was supplied by manure

Application of only manure or a combination of manure and mineral N resulted in similar emissions

ImplicationsImplications

Utilization of manures as a fertilizer source must be a accounted for in the estimation of N2O emissions from cropping systems.

Application of manure to a larger land base, even at lower rates, has the potential to increase overall annual N2O emissions.

AcknowledgementsAcknowledgements

• Bill Priddy, MaryKay Krasinski, Dianna Sturrock, and Jessica Agnew for all their efforts in the field and lab