Soil respiration and cropping system diversity
Jed Eberly Central Ag Research Center
December 10, 2019
What is soil respiration?
• Emission of carbon dioxide (CO2) from the soil • Due to activity of macro- and microorganisms
in the soil
Why is it important?
http://earthobservatory.nasa.gov/Features/CarbonCycle/
http://changingclimate.osu.edu/features/accounting-for-carbon
Nitrogen Cycle
Biomass nitrogen
Plant available nitrogen
Mineralization
N-mineralization
Nitrogen Management• Maximize return• Minimize cost
http://www.smart-fertilizer.com/articles/nitrogenHawkesford (2014) J Cereal Science. 59(3): 276-283
What controls soil respiration rates?
• Temperature• Moisture• Soil physical properties• Nutrient availability (e.g. N, P, Ca)• Availability and quality of soil carbon• Type and abundance of soil microorganisms
What controls soil respiration rates?
• Temperature• Moisture• Soil physical properties• Nutrient availability (e.g. N, P, Ca)• Availability and quality of soil carbon• Type and abundance of soil microorganisms
Project Objectives
• Determine the impact of increased cropping system diversity on respiration
• Measure the contribution of N mineralization to the N budget
Rotation And Tillage Study
Rotation And Tillage Study
• Microbial activity• Nitrogen
mineralization• Microbial community– Structure– Function
Winter wheat Fallow
Winter wheat
Spring wheat
Winter wheat Barley Winter
lentil
Winter wheat Barley Spring
pea
Spring wheat
Spring pea
Prosomillet Safflower
Methods
• Soil sampling– Total N– Nitrate N
• Soil respiration• N mineralization
0.0
0.1
0.2
Nov 01 Nov 15 Dec 01 Dec 15Date
Prec
ipita
tion
(inch
es)
0.0
0.5
1.0
1.5
2.0
10/31
11/05
11/10
11/15
11/20
11/25
11/30
12/05
12/10
12/15
12/20
Date
Aver
age
Res
pira
tion (u
mol
m−2
s−1 )
Treatment SP−MIL−SAF−SW WW−SW
Methods
+ ATP Luciferase
LuciferinLight
Soil core
Resin
Mineralization
Biomass
Soil Respiration
Fall 20180.0
0.1
0.2
Nov 01 Nov 15 Dec 01 Dec 15Date
Prec
ipita
tion
(inch
es)
0.0
0.5
1.0
1.5
2.0
10/31
11/05
11/10
11/15
11/20
11/25
11/30
12/05
12/10
12/15
12/20
Date
Aver
age
Res
pira
tion (u
mol
m−2
s−1 )
Treatment SP−MIL−SAF−SW WW−SW
Spring 20190.00
0.25
0.50
0.75
Apr 01 Apr 08 Apr 15 Apr 22Date
Prec
ipita
tion
(inch
es)
0.4
0.8
1.2
04/04
04/09
04/14
04/19
Date
Aver
age
Res
pira
tion (u
mol
m−2
s−1 )
Treatment SP−MIL−SAF−SW WW−SW
0.0
0.5
1.0
Jun Jul Aug Sep OctDate
Prec
ipita
tion
(inch
es)
1
2
3
05/09
05/14
05/19
05/24
05/29
06/03
06/08
06/13
06/18
06/23
06/28
07/03
07/08
07/13
07/18
07/23
07/28
08/02
08/07
08/12
08/17
08/22
08/27
09/01
09/06
09/11
09/16
09/21
09/26
10/01
10/06
10/11
Date
Aver
age
Res
pira
tion (u
mol
m−2
s−1 )
Treatment SP−MIL−SAF−SW WW−SW
Respiration rate of changeRain event WW-SW SP-MIL-SAF-SW
5/16/19 0.42 0.225/27/19 0.44 0.316/11/19 0.16 0.246/22/19 0.37 0.279/24/19 0.20 0.18
Fall 2018 Spring 2019
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
SW-WW SP-MIL-SAF-SW
Aver
age
Resp
iratio
n Ra
te (μ
mol
CO
2m
-2s-1
)***
0
0.2
0.4
0.6
0.8
1
1.2
1.4
SW-WW SP-MIL-SAF-SW
Aver
age
Resp
iratio
n Ra
te (μ
mol
CO
2m
-2s-1
)0.0
0.5
1.0
1.5
2.0
2.5
SW-WW SP-MIL-SAF-SW
Aver
age
Resp
iratio
n Ra
te (μ
mol
CO
2m
-2s-
1 )
Summer 2019
Factor Rs (2018) Rs (2019)
Cropping system (CS) <0.001 0.192
Soil Temperature <0.001 <0.001
Soil Moisture 0.899 <0.001
Air Temperature <0.001 0.010
CS*Soil Temperature 0.333 0.391
CS*Soil Moisture 0.732 0.088
CS*Air Temperature 0.001 0.042
Soil temp*Soil moisture 0.038 <0.001
CS*Soil temp*Soil moisture <0.001 0.667
ANOVA
Results
SW-WW
SP-MIL-
SAF-SW
0
1
2
3
4
Nitr
ate-
N (p
pm)
SW-W
W
SP-MIL-
SAF-SW
1000
1500
2000
2500
Tota
l N (p
pm)
**
Expected OutcomesTemperature & Precipitation effects on activity
Determine differences in N-mineralization in diversified cropping systems
• Provide guidance for fertilizer application
• Leaching risk
Acknowledgements
Project Personnel• Pat Carr• Clain Jones• Simon Fordyce
CARC Staff• Eva Magnuson• Jenni Hammontree
FundingMontana Fertilizer Advisory Committee
Questions
Jed EberlyAssistant ProfessorMSU Central Ag Research Center52583 US Hwy 87Moccasin, MT 59462Phone: 406.423.5421Email: [email protected]