Dr. Dan Undersander University of Wisconsin · 1st spring 1st fall year 2 spring year 2 fall year 3...
Transcript of Dr. Dan Undersander University of Wisconsin · 1st spring 1st fall year 2 spring year 2 fall year 3...
Dr. Dan UndersanderUniversity of Wisconsin
Dan Undersander-Agronomy © 2014
1) Higher initial seeding rate
2) Seeding into existing alfalfa fields
Dan Undersander-Agronomy © 2014
0
2
4
6
8
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1989 1990 1991
Plan
ts p
er s
quar
e fo
ot
6
12
15
18
20
Dan Undersander-Agronomy © 2014
Data from Kephart et al., Agron. J. 84:827-831 (1992)
Dan Undersander-Agronomy © 2014
30
40
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60
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5 22
% de
ath
Plants per sq ft Data from Hall et al., Agron. J. 96:717–722 (2004).
Plants per square foot over time
020406080
100120
1st s
prin
g1s
t fal
lye
ar 2
spr
ing
year
2 fa
llye
ar 3
spr
ing
year
3 fa
llye
ar 4
spr
ing
year
4 fa
llye
ar 5
spr
ing
plan
ts/f
t2 Principle: At higher seeding rates
more plants emerge
More seedlings die in seeding year.
Same stand density at end of seeding year
Dan Undersander-Agronomy © 2014
0
20
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60
30 day 180 day
Plan
ts p
er s
qft
Meadow Fescue
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30
45
60
75 0
5
1015
20
30 day 180 day
Plan
ts p
er s
qft
Orchardgrass
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45
60
75
0
20
40
60
30 day 180 dayPlan
ts p
er s
qft
Tall Fescue
15
30
45
60
Dan Undersander-Agronomy © 2014
Data from Kephart et al., Agron. J. 84:827-831 (1992)
Dan Undersander-Agronomy © 2014
0
1
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3
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1989 1990 1991
Yiel
d, to
ns D
M/a 6
12
15
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20
Principle: At higher seeding rates
more plants emerge
Same stand density at end of seeding year
Same stand and yield in production years0
1
2
3
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8
1989 1990 1991
Yiel
d, to
ns D
M/a 6
12
15
18
20
Stems per plant
0
5
10
15
20
Num
ber
of s
tem
s
Plants per square foot over time Stems per plant and ft2
020406080
100
1st s
prin
g1s
t fal
lye
ar 2
spr
ing
year
2 fa
llye
ar 3
spr
ing
year
3 fa
llye
ar 4
spr
ing
year
4 fa
llye
ar 5
spr
ing
plan
ts/f
t2
020406080
100120140
Num
ber
of s
tem
s per plant
per sq ft
Dan Undersander-Agronomy © 2014
Does higher seeding rate increase seeding year yield?
Is it economical?
Seeding rate Additional seed cost
Additional yield needed to cover cost ($200/t)
lb/a $5/lb $7/lb ------t/a------12 --- ---18 $30 $42 0.15 0.2124 $60 $84 0.30 0.42
Dan Undersander-Agronomy © 2014
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alfalfa Meadow fescue Orchardgrass Tall Fescue
Yiel
d, D
M t/
a 15%
30%
45%
60%
75%
Dan Undersander-Agronomy © 2014
First cutting yieldSeeding rate -----Yield, DM t/a-----
Lb/a Connell, WA Arlington, WI8 2.1 2.2
13 2.3 2.518 2.5 2.623 2.4 2.5
55VR06 plantedData from Pioneer Hybrid Intl,
Dan Undersander-Agronomy © 2014
First cutting yieldSeeding rate -----Yield, DM t/a----- $ return*
Lb/a Connell, WA Arlington, WI8 2.1 2.2 --
13 2.3 2.5 $1518 2.5 2.6 -$523 2.4 2.5 -$55
* = value of additional hay – additional seed cost55VR06 plantedData from Pioneer Hybrid Intl,
Dan Undersander-Agronomy © 2014
Alfalfa is synthetic population – each plant genetically different
Aphanomycesphytophthora Aphanomyces
phytophthora
verticilliumphytophthora Aphanomyces
phytophthora
verticilliumphytophthora
verticilliumphytophthora
Dan Undersander-Agronomy © 2014
Dan Undersander-Agronomy © 2014
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1
2
3
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5An
nual
Ryeg
rass
Dip
loid
Annu
alRy
egra
ssTe
trap
loid
chec
kno
thin
gin
tere
seed
ed
Orc
hard
gras
s
Sorg
hum
-su
dang
rass
Yie
ld (
t/a)
1997
1998
1999
Dan Undersander-Agronomy © 2014
Interseeding grasses into alfalfa◦ Ryegrass responds quickly but does not grow well in
summer heat or drought◦ Orchardgrass and tall fescue take 60 to 90 days to
begin producing yield
Dan Undersander-Agronomy © 2014
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Plan
ts p
er s
q ft
Date after seeding
none
medium
high
Source: Rachael Long, Univ of CA
Original Alfalfa Stand
Dan Undersander-Agronomy © 2014
When turning over alfalfa need to wait 1 to 2 years before reseeding due to autotoxicity
Alfalfa will provide adequate nitrogen for corn for 1 year and barley or canola for 1 to 2 years
Barley, canola, corn will yield more following alfalfa than barley following barley or canola following canola
Dan Undersander-Agronomy © 2014
Prior Rotation
Dan Undersander-Agronomy © 2014
ContinuousCorn
Alfalfa 2011Corn 2012
Prior Rotation
Dan Undersander-Agronomy © 2014
Variety
Brillion seeder
John Deere Drill
lb seed per acre 1 18.3 21.4 2 17.0 20.3 3 15.0 16.3 4 13.8 16.3 5 20.8 16.5 6 20.3 16.8
Two seeders, no change in setting, 6 different varieties
Dan Undersander-Agronomy © 2014
Alfalfa seeding rates above 12 lb/a ◦ Do not increase stand or yield in seeding year◦ Do not increase yield in production years
Interseeding crop into thin alfalfa stands does not increase yield
Alfalfa autotoxicity can reduce new alfalfa stand growth for up to 2 years on medium to heavy soils