Diversifying Dryland Grain
Cropping Systems for Organic
Production
• Background of Region and Organic Wheat
Production
• Dryland Organic Grain Production from Transition
to Certification
• Intercropping winter pea and wheat for optimal soil
nitrogen and moisture
• Dryland organic grain management considerations
• Sub humid Region
– 500 mm annual precipitation (21 inches)
– 60% precipitation November through March
• Rain-fed annual cropping systems
• Soft White Winter Wheat
• 2 to 3 year rotations
– Winter Wheat – Spring Legume – Spring Wheat
– Winter Wheat – Spring Legume – Winter Wheat
– Winter Wheat – Winter Wheat – Winter Wheat
Papendick, 1996; Cook, 1986; McCool et al., 2001
Which of the following are your main reasons for NOT
having any certified organic acres?
%
Organic weed control methods are inadequate
69.3
Cannot get same yields with organic as conventional methods 59.3
Organic pest/disease control methods are inadequate
58.9
Not worth the time
43.4
Transportation and access to organic buyers are limited
36.3
Too difficult to get enough nitrogen
35.9
Need more information on organic production
33.2
Certification is too much trouble
24.3
Other reasons
17.8
Jones et al., 2006
Within the last five years, 2001 – 2005, have you
considered transitioning any of your acreage to certified
organic?
Jones et al., 2006
Dryland Organic Grain
Production from Transition
to Certification
(AKA The Boyd Farm Project)
Dryland organic cropping systems
• Identify strategies to minimize economic and
management risks for organic grain growers
• To evaluate different transition cropping
systems
– Do not rely on inversion tillage
– Supply N using legume crops (grain,
green manure and forage)
• To identify how cropping systems in
transition phase impacted grain yield and
protein during the certified organic phase.
• To develop a soil fertility management plan
for organic grain producers.
– Construct a nitrogen budget
Materials and Methods
Experimental Design
Rotation Systems
Transition Phase
Certifiable Organic Phase
Year
System
2003
2004
2005
2006
2007
Spring Wheat
Winter Wheat
Control Rotation
1
Spring Wheat
Winter Wheat
Spring Barley
3 yr of Grain Cropping
2
Spring Pea
Winter Wheat
Spring Pea
Spring Wheat
Winter Wheat
3
Spring Pea
Spring Wheat
Spring Pea
Spring Wheat
Winter Wheat
2 yr of Grain Cropping + 1 yr Green Manure
4
Spring Pea
Winter Wheat
Winter Pea GM
Spring Wheat
Winter Wheat
5
Spring Pea
Spring Wheat
Winter Pea GM
Spring Wheat
Winter Wheat
1 yr of Grain Cropping + 2 yr Green Manure
6
Fava Bean GM
Winter Wheat
Winter Pea GM
Spring Wheat
Winter Wheat
7
Fava Bean GM
Spring Wheat
Winter Pea GM
Spring Wheat
Winter Wheat
Spring Wheat
Winter Wheat
Spring Wheat
Winter Wheat
3 yr Green Manure
8
Fava Bean GM
Winter Pea GM
Winter Pea GM
Legume/Grass Forage
9
Alfalfa + Oat/Pea
Alfalfa + Oat/Pea
Alfalfa + Oat/Pea
General Agronomics
• 2x Seeding Density
• Cereal Crops
– BioGro 7-7-2 NPK
– Foliar Fish Emulsion 12-0.25-1 NPK
– Gypsum
• Pre-plant weed control and soil prep.
• 1-2 passes
• In-crop weed management
• 3-5 passes
Sub Sampling
• Crops and Weeds
– Separated and biomass yield was determined
– Total N
– Grain N measured separately
• Soil Samples
– 1.5 m depth
– Inorganic N
• Green Manure Crops were Flail Mowed
– Residue retained on soil
• Forage cut 1-2x season
– Baled as hay
• Grain Harvested
Gallagher, R.S., D. Pittmann, A.M. Snyder, R.T. Koenig, E.P. Fuerst, I.C. Burke, & L.
Hoagland, 2010. Alternative strategies for transitioning to organic production in directseeded grain systems in Eastern Washington I: Crop agronomy. Journal of Sustainable
Agriculture 34:483-503.
• Net N input = (Fertilizer N + Plant N +
Post-harvest Soil N) – Pre-plant Soil N
– Fertilizer N = organic N when applied to cereal crops
– Plant N = crop N + weed N
– Pre-plant soil N = post-harvest soil N from the previous year
• Net N Balance = Net N input – N removal
(crop)
– Net N input = equation above
– Crop N removal = grain or forage crop N only
Net System Nitrogen Balance (by year)
300
2003
2004
2005
Net System N Balance (kg ha-1)
x
250
x
x
200
x
x
x
xy
150
b
ns† yz
100
b
b
b
b
b
b
a
b
z
50
0
Cropping System
ns = not significant 2003; ab for 2004; xyz for 2005
r-
Fo
r-
Fo
r
-W
P
-W
P
B
B
Fo
-W
W
-S
B
B
B
B
P
P
-W
W
-W
W
-S
P
S
-W
P
S
P
-W
-W
W
W
-S
P
S
P
P
-S
P
-S
-W
W
P
S
S
W
-W
W
-S
B
-50
Soil Inorganic Nitrogen (by year)
Soil Inorganic Nitrogen (kg ha-1)
160
2003
2004
2005
140
b ns
120
b
b
b
b
b
b
a
b
ns†
100
80
60
40
20
Cropping System
† ns = not significant (2003 and 2005); ab for 2004
Fo
r
P
r-
-W
Fo
rFo
B
B
-W
P
-W
P
P
-S
W
-W
B
B
W
B
-W
-W
B
-S
W
-W
S
P
W
P
P
P
-S
P
-W
S
S
P
-S
W
W
-W
S
P
S
W
-W
W
-S
-S
P
B
0
Certified Organic Phase
Results
2006 Spring Wheat Yield (bars) and Protein (dots)
5000
14
x
y
y
x
x
x
x
12
y
10
ha-1
3000
8
6
2000
cde
e
de
bcd
de
abc bcd
ab
a
4
1000
2
SP
W
-S
-W
W
SP
-W
- S SP
W
SP
- W SP
W
SP
-W
P
-S
W
BB
- W WP
W
BB
-W
P
-S
W
BB
-W
P
-W
P
-W
Fo
rP
Fo
rFo
r
0
B
0
Cropping System
Protein (%)
3293 kg
SW
Grain Yield (kg·ha-1)
4000
x
2007 Winter Wheat Yield (bars) and Protein (dots)
5052 kg ha-1
5000
12
x
y
y
x
x
x
y
y
10
3000
6
d
2000
bcd
cd
a
ab
a
a
abc abcd
4
1000
2
P
-S
SP
W
-S
SP
-W
W
-S
-S
SP
-W
W
P
-W
W
-W
SP
P
-S
W
BB
-W
-W
P
W
-W
BB
P
-S
W
-W
BB
P
-W
P
-W
Fo
rP
Fo
rFo
r
0
B
0
Cropping Systems
Protein (%)
8
SW
Grain Yield (kg ha-1)
4000
x
Soil Inorganic N in Certified Organic Phase
180
Sp 2006
Fa 2006
Fa 2007
Soil Inorganic N (kg ha-1)
160
140
†ns
120
100
bc
e
yz
80
e
wxy
bc
cd
a
ab
de
e
z
wx
w
wx
wx
w
xyz
60
40
20
SP
SW
-W
W
-S
B
-W
W
SP
-S
P
-S
W
SP
-S
P
-W
W
SP
-W
P
-S
W
BB
-W
-W
P
W
BB
-W
P
-S
W
BB
-W
P
-W
P
-W
Fo
rP
Fo
rFo
r
0
Cropping Systems
†ns (not significant) for Sp 2006; abc for Fa 2006; wxy for Fa 2007
Summary
• Certified organic grain had some of the
highest yields and protein levels following
Forage systems in the 1st year
– decreased 2nd year
• Green manure in 3rd year of transition
resulted in some of the highest grain
yields 2nd year
– High protein levels both years
Intercropping winter pea
and wheat for optimal soil
nitrogen and moisture
Intercropping
• The simultaneous cultivation of more than
one crop species on the same piece of land
with part of the crop life-cycles overlapping.
(Hauggaard-Nielsen et al., 2008; Walker et al., 2011; Pridham and Entz, 2008).
Benefits of Intercropping
•
•
•
•
•
•
•
•
Source of plant N to cereal crops
Suppress weeds
Reduce disease
Stabilize erodible soils
Increase SOM
Provide crop rotation options
Management tool in organic or low-input systems
Reduce time spent growing a green manure
(Walker and Ogindo, 2003; Blackshaw et al., 2010; Hauggaard-Nielsen et al., 2008;
Walker et al., 2011; Liebman and Dyck, 1993; Thiessen Martens et al., 2005;
Lithourgidis et al., 2011; Hartl 1989; Reynolds et al., 1994)
Objective
• Determine the optimal time to mechanically
remove winter pea intercropped with winter
wheat
– Improve N input
– Reduce soil moisture stress
Materials and Methods
Experimental Design
• Seeded Mid-October
• Winter Wheat
– (Triticum aestivum L. cv. ‘Brundage 96’)
• Winter Pea
– (Pisum sativum L. cv. ‘Granger’)
• “Direct seeded” 2.2 m wide Fabro® no-till drill
– Wheat 135 lbs. acre-1; 15” row spacing
(152 kg ha-1; 38 cm row spacing)
– Pea 200 lbs. acre-1; 15” row spacing
(225 kg ha-1; 38 cm row spacing)
Treatments
25% Cover
Early May
50% Cover
Mid May
75% Cover
Early June
100% Cover
Late June
Intercrop
No Removal
No Intercrop
Control
Soil Samples
– Pre and Post season 1.5 m
– 0 to 30 cm
– Repeated each sampling date
– Gravimetric water content
– Inorganic nitrogen
Plant Biomass
– 0.3 m2 collected on each sampling date
– Repeated each sampling date
– Dried and weighed
Grain Yield
–
Late August
Inter-row Cultivator
Results
% Soil Moisture (0-30 cm) Over Time
2010
2011
30
30
15
5/
1/
11
0
10
/1
/1
10
1/
9/
1/
8/
1/
7/
1/
6/
10
0
10
0
10
5
Sampling Date
9/
1/
11
10
5
1/
5/
20
8/
1/
11
10
25
7/
1/
11
15
Control
25% Cover
50% Cover
75% Cover
100% Cover
Harvest
6/
1/
11
20
10
Soil Moisture (%) 0-30 cm
25
Soil Moisture (%) 0-30 cm
Control
25% Cover
50% Cover
75% Cover
100% Cover
Harvest
Soil Moisture (0 – 1.5 m) Pre and Post Season
2010
2011
18
18
16
16
14
14
Soil Moisture (%) 0 - 1.5 m
Soil Moisture (%) 0 - 1.5 m
ns
12
10
8
6
12
10
8
a
4
4
2
2
0
e
Pr
ea
-S
s
on
l
r
r
va
ve
ve
o
o
o
n
C
C
C
C
em
Co
%
%
%
%
R
0
5
0
5
2
5
7
10
No
l
tro
er
ov
er
ov
b
ab ab b
b
b
6
0
on
s
ea
e-S
Pr
Treatment
l
tro
n
Co
%
25
l
r
r
r
er
va
ve
ve
ve
o
o
o
o
C
C
C
m
%
%
Re
0%
o
0
50
75
1
N
v
Co
Soil Inorganic Nitrogen (0-30 cm) Over Time
2010
Control
25% Cover
50% Cover
75% Cover
100% Cover
Harvest
60
50
40
30
20
10
60
50
40
30
20
Sampling Date
9/
1/
11
8/
1/
11
7/
1/
11
6/
1/
11
0
/1
/1
10
10
1/
9/
10
1/
8/
10
1/
7/
1/
10
0
6/
10
1/
Control
25% Cover
50% Cover
75% Cover
100% Cover
Harvest
10
0
5/
Soil Inorganic N (kg ha-1) 0-30 cm
70
5/
1/
11
Soil Inorganic N (kg ha-1) 0-30 cm
70
2011
Soil Inorganic N (0 – 1.5 m) Pre and Post Season
2011
140
140
120
120
100
-1
100
Soil Inorganic N (kg ha ) 0 -1.5 m
Soil Inorganic N (kg ha-1) 0 - 1.5 m
2010
80
a
60
b
b
b
ab ab b
40
20
80
60
40
a
20
0
on
e
Pr
as
e
-S
l
l
r
r
r
r
va
ve
ve
ve
ve
tro
o
o
o
o
o
n
m
C
C
C
C
Co
%
%
%
%
Re
0
5
0
5
2
5
7
10
No
b
b
b
b
b
b
0
Pr
l
n
ol
er over over over
ova
aso Contr Cov
m
C
C
C
e
25% 50% 75% 100% No R
e
e -S
Treatment
Wheat Biomass Variation with Intercrop
Removal Time
350
2010 Wheat w/ pea removed
2010 Wheat w/ pea all season
2011 Wheat w/ pea removed
2011 Wheat w/ pea all season
-2
Biomass Yield (g m )
300
250
a
x
a
x
200
150
100
50
0
5/3
5/17
5/31
Sampling Date
6/14
6/28
8000
Wheat Grain Yield after Pea Removal for
Different Crop Growth Phases
2010
2011
8000
ns
ns
ns
6000
5666 kg
ha-1
-1
Grain Yield (kg ha )
Grain Yield (kg ha-1)
6000
4000
Mean = 5560 kg ha-1
2000
4000
Mean = 3527 kg ha-1
2000
0
0
n
Co
l
tro
er
%
25
v
co
er
%
50
v
co
er
%
75
v
co
%
0
10
v
co
er
0r
e
v
mo
al
n
Co
Treatment
tro
l
25
%
co
ve
r
50
%
co
r
ve
75
er
%
v
co
10
0%
co
al
r
ve
0r
e
v
mo
Summary
• No differences in soil moisture
• No difference in soil nitrogen
• No difference in grain yield or protein
• No difference among plant N levels or
biomass yield
Dryland Organic Grain
Management Considerations
Agronomics
• Reduced tillage weed control (in crop)
– Rotary Hoe
– Rotary Harrow
– Inter-row Cultivator
• Choose competitive crops and cultivars
– Winter Crops > Spring Crops
Agronomics
• Peas established better with wheat
• Biodiversity in intercrop system
Soil Fertility
• Include a forage system during the
transition ($)
– Supplement soil N following 1st year of grain
production
• Include a green manure during the last
year
– Multiple years of green manure likely not
necessary
Soil Fertility
• External (commercial) organic fertilizer
sources are too expensive
• Adding a source of animal manure may be
beneficial
Acknowledgments
Committee Members
Dr. Rich Koenig (Co-Chair)
Dr. Ian Burke (Co-Chair)
Dr. Dave Huggins
Dr. Scot Hulbert
Special Thanks
Dr. Bill Pan
Dr. Pat Fuerst
Co-Authors
Dr. Rob Gallagher
Dr. Lori Hoagland
Dr. Kate Painter
Amanda Snyder
Misha Manuchehri
Farmers
Pat and Lester Boyd
Technicians
Dennis Pittmann
Rod Rood
John Rumph
Margaret Davies
Dave Uberaga
Undergraduate Assistants
Charlie Clark
Lydia Baxter Potter
Madeline Jacobsen
Heather Fuerst
Nick Boydson
Rachel King
Questions?