Agronomy in the Context of Conservation Agriculture:
Nutrient Management
Eric Miller, Ivan Ortiz-Monasterio, and Bill Raun
Beyond Diagnostics: Insights and Recommendations from Remote Sensing
December 14th, 2013
Update on the Trimble® GreenSeeker handheld crop sensor
Progress with the OSU singulating hand-held planter ◦ Capable of singulating corn seeds and applying
fertilizer nitrogen as urea beneath the soil’s surface
Talking points
Sensor Extension, Ciudad Obregon, MXDr. Ivan Ortiz-Monasterio
Trimble® GreenSeeker handheld crop sensor
Objective◦ Develop a small and cost-effective NDVI sensor to
duplicate the results of a commercial GreenSeeker sensor (Crain et al., 2012)
Picture courtesy of Jared Crain
MSRP $495 USD
Handheld sensor
Relationship with the GreenSeeker
0.0 0.2 0.4 0.6 0.8 1.00.0
0.2
0.4
0.6
0.8
1.0
f(x) = 0.96926977718988 x + 0.0548179444811671R² = 0.872395617435364
Handheld NDVI
Gre
en
Seeker
ND
VI
Slope = 1 Intercept = 0
Regression model parameters
Model parameters and analysis of variance; slope equal to 1 and intercept equal to 0
Sensor ReadingsParameter of the
model† R2 nSignificance
(Pr > F)
NDVI a b Intercept Slope
All 0.05 0.97 0.88 1485 <0.001 0.001
Greater than 0.50 -0.08 1.21 0.72 160 0.002 <0.001
Less than 0.50 0.07 0.93 0.78 1325 <0.001 <0.001
† a = intercept, b = slope
nue.okstate.edu
#6 Trigo (Mexico)
nue.okstate.edu
OSU singulating hand-held planter
Opico Quezaltepeque, El Salvador
Remove chemically treated seeds from the hands of small farmers
Decrease soil erosion via improved plant spacing
Accommodate mid-season application of fertilizer (N and P)
Place urea below the surface reducing NH3 losses
Potential to increase third-world maize production and NUE
Benefits
Hand planter iterations
875,098,631 Mg maize 176,991,927 ha of maize
◦ 4.95 Mg ha-1
>50,000,000 ha in the developing world
60% planted by hand◦ 20,645,000 ha or 13% of the
total maize area in the world
Potential impact
FAOstat, 2013
Hand Planter Testing: 2013
Ciudad Obregon, MXDr. Ivan Ortiz-
Monasterio
1,000,000 cycles0.29g/seed60,000 seeds/ha3443 seeds/kg1.0 kg hopper 17 times refill
nue.okstate.edu/Hand_Planter.htm
seed size (2653-4344 seeds/kg)
seed type and shape fertilizer
Third world maize yields hover near 2.0 Mg ha-1 (Dowswell, et al., 1996)
“OSU Hand Planter”
Drum, tip, orientation, cavity (seed size, brush, housing,
user)
4 6 8 10 120
20
40
60
80
100 P-450
P-260
R-450
R-260
T-P450
T-P-260
T-R-450
T-R-260
checkDays after planting
Emer
genc
e, %
Maize emergence delayed by as few as four days, resulted in a yield depression of 15 percent (Hodgen et al., 2007)
Homogeneity in maize plant spacing, plant stands, and emergence can decrease plant-to-plant variation and increase grain yields (Nielsen, 1997; Martin et al., 2005)
Thailand Mexico ZambiaEl Salvador Guatemala
Questions?
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