Cover Crops and Nutrient Cycling - Ruark
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Matt Ruark University of Wisconsin-Madison University of Wisconsin-Extension COVER CROPS & NUTRIENT CYCLING 2015 Iowa Cover Crops Conference February 17-18, West Des Moines, IA
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Transcript of Cover Crops and Nutrient Cycling - Ruark
Matt Ruark
University of Wisconsin -Madison
University of Wisconsin -Extension
COVER CROPS &
NUTRIENT CYCLING
2015 Iowa Cover Crops Conference
February 17-18, West Des Moines, IA
Jim Stute-UWEX
Mike Ballweg-UWEX
Kevin Shelley – NPM
Richard Proost –
NPM
Jaimie West – UW-
Madison
Megan Chawner –
UW Discovery Farms
Wisconsin Fertilizer
Research Council
SARE
UWEX
Wisconsin Farmers
COLLABORATORS & FUNDING
N credits from clovers
N uptake and N credits from radish
N uptake from rye and effect on soil nitrate
OUTLINE
PLANO SILT LOAM (TYPIC ARGIUDOLL)
Immediate reduction in N loss through uptake
Providing a nitrogen credit (green manure)
Increasing subsequent crops yield
Three types of cover crops evaluated:
Legumes (for the N credit)
Grasses (for the N uptake)
Radish (for the N uptake; for an N credit?)
SHORT-TERM BENEFITS OF COVER CROPS
RED CLOVER
No clover
y = 104.9 + 0.9459x - 0.0026x2
r2 = 0.9021
N max = 182
Clover
y = 176.8 + 0.5318x - 0.0021x2
r2 = 0.3083
N max = 127
0
50
100
150
200
250
0 40 80 120 160 200 240
N Rate (lb/a)
Yie
ld (
bu
/a)
Clover No clover
N Credit, 55 lb/acre
Stute and Shelley, unpublished
Corn response to nitrogen, Janesville 2010
Pictures taken October 1, 2013
SUMMER SEEDED LEGUMES
Oct. 25, 2013
Ballweg, UWEX
Berseem Crimson
177 lb-N/ac AGB117 lb-N/ac AGB
Three locations in
WI
Radish vs. no radish
following winter
wheat
Objective: determine
if there is a nitrogen
credit for radish
RADISH STUDIES
N UPTAKE – ROCK CO.
2011 Radish N Uptake, Rock Co.
Radish Radish+60 Winter wheat
Nitro
ge
n u
pta
ke
(lb
/ac)
0
50
100
150
200
2502012 Radish N Uptake, Rock Co.
Radish Radish+60 Winter wheat
Nitro
ge
n u
pta
ke
(lb
/ac)
0
20
40
60
80
100
180 180
120
70
40
20
2012 SOIL NITRATE (PPNT)
May 2012, Soil Nitrate @ Rock Co.
Rad
ish
(0-1’)
Rad
ish
(1-2’)
Rad
ish+
60 (0
-1’)
Rad
ish+
60 (1
-2’)
No
radish
(0-1’)
No
radish
(1-2’)
So
il n
itra
te (
pp
m)
0
10
20
30
40
50
N credit =
130 lb/ac
N credit =
190 lb/ac
N credit =
45 lb/ac
2012 Corn Yield, Rock County, WI
Nitrogen Rate (lb/ac)
0 50 100 150 200 250
Co
rn Y
ield
(b
u/a
c)
100
120
140
160
180
200
None
Radish
Radish+60
2013 SOIL NITRATE (PPNT)
May 2013, Soil Nitrate @ Rock Co.
Rad
ish
(0-1’)
Rad
ish
(1-2’)
Rad
ish+
60 (0
-1’)
Rad
ish+
60 (1
-2’)
No
radish
(0-1’)
No
radish
(1-2’)
So
il n
itra
te (
pp
m)
0
1
2
3
4
5
6
7
No N credit based on PPNT in 2013
2013 Corn Yield
0 50 100 150 200 250
60
80
100
120
140
160
180
200
220
No Radish
Radish
Radish + 60N
Co
rn Y
ield
(b
u a
c-1)
N Rate (lb ac-1)
Error bars represent standard error.
2013 CORN YIELDS
WASHINGTON COUNTY, WI
NO-TILL CORN FOLLOWING WINTER WHEAT
No effect of radish on yield or response to N in 2012 as well.
Across six site years, we have not been able to
determine a nitrogen credit from radish with N
response yield data.
Is it doing something to the soil – how often will this
result in a yield increase?
Most likely will be part of mixtures rather than pure
stands.
RADISH CONCLUSIONS
Reduces soil erosion
Reduces nitrate leaching
Potential to use as a forage crop
GRASSES
Continuous corn silage w/ fall manure application
(10,000 gal/ac of liquid dairy manure)
Fall-planted winter rye (90 lb live seed/ac)
1) No cover crop
2) Winter rye as a cover crop
3) Winter rye as a forage crop (ryelage)
STUDY DESIGN
RYE COVER CROP ABOVEGROUND BIOMASS
Termination date
4/12/12 5/1/13 5/12/14
Dry
ma
tte
r, lb
/ac
0
1000
2000
3000
4000
115 lb N/ac
11 lb N/ac 11 lb N/ac
RYELAGE ABOVEGROUND BIOMASS
Harvest date
5/10/12 5/21/13 5/30/14
Dry
ma
tte
r, lb
/ac
0
2000
4000
6000125 lb N/ac
65 lb N/ac73 lb N/ac
SOIL NITRATE AT CORN PLANTING
2012
No
CC
Rye
CC
Rye
lage
Soil
NO
3- -N
, p
pm
0
5
10
15
20
252013
No
CC
Rye
CC
Rye
lage
2014
Cover Crop Treatment
No
CC
Rye
CC
Rye
lage
0
5
10
15
20
25
0-12"
12-24"
Corn silage yield, 2012
Arlington, WI
N rate, lb N/ac
60 100 160
Yie
ld (
65
% m
ois
ture
), t
on
/ac
0
5
10
15
20
25
30
No CC
Rye CC
Ryelage
RESULTS
Ryelage = 13 ton/ac
RESULTS
Total forage:
Corn silage
+ Ryelage
Corn silage yield, 2012
Arlington, WI
N rate, lb N/ac
60 100 160
Yie
ld (
65
% m
ois
ture
), t
on
/ac
0
5
10
15
20
25
30
No CC
Rye CC
Ryelage
Corn silage yield, 2013
Arlington, WI
N rate, lb N/ac
60 100 160
Yie
ld (
65
% m
ois
ture
), t
on
/ac
15
20
25
30
35
No CC
Rye CC
Ryelage
RESULTS
Ryelage = 6.5 ton/ac
RESULTS
Total forage:
Corn silage
+ Ryelage
Corn silage yield, 2013
Arlington, WI
N rate, lb N/ac
60 100 160
Yie
ld (
65
% m
ois
ture
), t
on
/ac
15
20
25
30
35
No CC
Rye CC
Ryelage
N rate, lb N/ac
60 100 160
Yie
ld (
65
% m
ois
ture
), t
on
/ac
20
25
30
35
40
No CC
Rye CC
Ryelage
Corn silage yield, 2014
Arlington, WI
Error bars represent standard error.
RESULTS
Ryelage = 5.8 ton/ac
RESULTS
N rate, lb N/ac
60 100 160
Yie
ld (
65
% m
ois
ture
), t
on
/ac
20
25
30
35
40
No CC
Rye CC
Ryelage
Total forage:
Corn silage
+ Ryelage
Corn silage yield, 2014
Arlington, WI
Error bars represent standard error.
Winter rye as a cover crop did not affect corn silage
yield
Winter rye as a forage crop reduced corn silage yield
in 2 of 3 years.
Led to greater total production in 2 of 3 years and the
same amount of total production in 1 of 3 years
CONCLUSIONS
Clovers provide the clearest value (N fertilizer) –
but can you get clovers into Iowa cropping
systems?
The benefits of radish to corn crop are unclear
Rye, if killed early, provides good erosion control
and should not negatively impact corn yields
Potentially huge benefit of rye as a cover AND
forage but needs to be evaluated in all soil types.
HOW TO MAKE COVER CROPS PAY
QUESTIONS?
COMMENTS?
CONCERNS?
