single plant yields: the ne experience. why talk about individual plants when farmers are shelling...
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Single plant yields: The NE experience.
Why talk about individual plants when farmers are shelling up to 40ft swaths?
Because there is more to the story then what meets the combine!!!!!
Lets talk about yield per area and yield per plant over the past 40 years!
y = 1.8326x - 3522.9
R2 = 0.65
0
20
40
60
80
100
120
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160
180
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1960 1970 1980 1990 2000 2010Year
bu
ac
-1
0
2,000
4,000
6,000
8,000
10,000
12,000
kg h
a-1
Data from USDA NASS objective yield data available online http://www.usda.gov/nass
Average Yields reported for 5 states: IA, IL, IN, MN, NE
2010 5 state avg. = 160 bu ac-1
2020 5 state avg. = 180 bu ac-1
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
1960 1970 1980 1990 2000 2010Year
Pla
nts
ac-1
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
Pla
nts
ha-1
IA IL NE
MN IN NE IRR.
Data from USDA NASS objective yield data available online http://www.usda.gov/nass
Data from USDA NASS objective yield data available online http://www.usda.gov/nass
2010 28,427 plants ac-1
2020 31,261 plants ac-1
y = 283.4x - 541207
R2 = 0.89
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
1960 1970 1980 1990 2000 2010
Year
Pla
nts
ac-1
5states
Linear(5states)
y = 0.3638x - 585.82R2 = 0.05
0
20
40
60
80
100
120
140
160
180
200
1960 1970 1980 1990 2000 2010Year
g pl
ant-1
Data from USDA NASS objective yield data available online http://www.usda.gov/nass
Well what about those NCGA Contest winners?2004 winners are as follows:
332 bu ac-1
43,980 plants ac-1 Francis Childs192 g plant-1 Manchester, IA
320 bu ac-1 38,500 plants ac-1 Mark Dempsey211 g plant-1 Fowler, IL
296 bu ac-1 47,000 plants ac-1 Jeff Mezera160 g plant-1 Bagely, WI
Data available from http://www.ncga.com
So where is the rest of the story????
Lets look at within a given population at individual plant yield.
0
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150
200
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300
0 10 20 30 40 50 60 70 80 90 100
Half linear distance attributed to each plant (plant cm-1 )
Gra
in Y
ield
(g p
lant
-1)
Efaw 03 LCB 03 Efaw 04
Shelton 04 Ames 04 LCB 04
Henn 04
Plants with a neighbor on each side
Plants with a skip on one
side
Plants next to a double
skip
From the previous graph:1) Within each cluster, there is enormous amount of
variability.
2) In the first cluster of plants with a normally spaced neighbor, there can be 8x difference in yield.
3) Plants do not always adjust yield based on distance to its neighbors. Or they don’t always use the extra space.
Therefore, when converted in individual yield per area, maybe distorting the plants demand for nitrogen.
Consider three plants each yielding 150 g of grain,
1st plant has two normally spaced neighbors.2nd plant is missing a neighbor.3rd plant is missing both neighbors.
The first plant yield is higher per unit area because there is lessarea occupied.
The second plant has a lower yield per unit area because he as more area.
The third plant’s yield is drastically lower than the other two because it’s the only show in town.
Individual yield per unit area.
However, when averaged out over the entire acre the yield will be the same.
Grain Per Plant.More accurate picture of each plant’s potential needfor nutrients, but you need to know the number of plantsper acre.
As Nitrogen management resolutions become smaller therebecomes more of a need to know how many plants
are in that given area.
20 in rows in southwest Kansas (east of Liberal) Population = 38,500 ac-1 (95,095 ha-1)
If distance to nearest neighbor is not theMaster variable, then what is?
Maddonni, G.A., and M.E. Otegui. 2004. Intra-specific competition in maize:early establishment of hierarchies among plants affects final kernel set. Field Crops Res: 85:1-13.
Basically, Maddonni and Otegui said that hierarchies established at V6 are present at harvest.
Could these hierarchies be established earlier than V6and if so can nitrogen management per plant change these relationships?
By Plant NUE Study, Shelton, NE 2004
Plot size 4 rows (76 cm) 15 ft long,RCBD with 4 reps.9 N management treatments
Entire area was planted with a 4 row unit planterand plants were tagged when it was first visible by the eye with a plastic stake.
Treatment Structure
Application Time
Treatment V8 V8 VT
kg N ha-1 Dominate Dominated Dominate Dominated
----------------------------------ml UAN 28 % plant-1---------------------
1 56 0 0 3 6
2 56 0 0 6 3
3 0 3 6 0 0
4 0 6 3 0 0
5 0 0 0 3 6
6 0 0 0 6 3
7 0 168 (kg N ha-1) 0
8 0 0 168 (kg N ha-1)
9 0 0 0 0 0
By Plant NUE Study
Emerged 5 days after planting
Emerged 8 days after planting
If you had the power (A magic wand) and could meter out nitrogen per plant, which plant would you give more
nitrogen?
Side view with DAP stakesLooking straight down on same plants
How about these guys? Which plant should get the N?
Day after plant
# of Plants Mean Plant ht.
Stand. Dev.
5 47 79 1
6 403 76 0
7 612 72 0
8 286 69 1
9 63 66 1
10 74 58 1
11 13 56 3
12 20 51 2
0
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20
30
40
50
60
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80
90
5 6 7 8 9 10 11 12
Days after planting
Pla
nt h
eigh
t (cm
)
A A BB C
C D D EE F F G
G
Plant height measured from the ground to the tip of the tallest leaf when the leaves were folded up at approximately the V5 growth stage. Data taken on 6/26/04 (39 days after planting).
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5 6 7 8 9 10 11 12
Day of Emergence
Gra
in Y
ield
(g p
lant
-1)
Zero N check treatment.
0
25
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75
100
125
150
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225
250
5 6 7 8 9 10 11 12
Day of Emergence
Gra
in Y
ield
(g p
lant
-1)
Broadcast N treatment 150 lbs ac-1 (168 kg ha-1) at V8.
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0 50 100 150 200 250 300 350
Grain yield (g plant-1)
Har
vest
Inde
x
y = 1.1352x + 20.883
R2 = 0.70
0
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150
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0 50 100 150 200 250 300Stover Yield (g plant -1)
Gra
in Y
ield
(g
pla
nt
-1)
Conclusions:1) Over the long term we are increasing yields by
increasing plant population, and yield per plant is stable over time.
2)Individual yield per area may not reflect actual yield of the plant. But will average out over to the true mean per acre.
3) Yield per plant reflects each plant’s potential need for N. But you need to know the number of plants in acre.
4) Big plants yield more than little plants. Early emerging plants yield more than later emerging plants.
5) Nitrogen can boost yield of later emerging plants upto a certain point.
6) Very seldom does a plant yield over 200 g and even more rarely does it yield over 250 g per plant.
With that, Any Questions?
The good news is that to break the standing record (428.5 bu ac-1)posted by Francis Childs
(2002) at the same population he had (44,000 plants ac-1) by 1 bu ac-1 you only need to
average 248 g plant-1 !