Evaluation of NUE and WUE on Corn Hybrids With and Without Drought Tolerance in Irrigated
and Dryland Production Systems
Eric C. MillerJeremiah L. Mullock, Jacob T. Bushong, and William R.
Raun
ASA, CSSA, & SSSA Annual MeetingsTampa, FL
November 5st, 2013
Drought
The 2012 drought, 597 counties in 14 states primary natural disaster areas (USDA, 2013).
$14 billion in crop insurance indemnity payments (Congressional Budget Office, 2013).
Drought effects on corn
Cold shock protein B gene ◦ Called ‘cspB’◦ Bacillus subtilis bacterium
Cold shock proteins accumulate Act as RNA chaperones Bind and unfold tangled RNA molecules to
promote normal function (Castiglioni et al., 2008)
Transgenic trait/GMO
http://www.lhsc.on.ca/_images/Genetics/centraldogma.jpg
Express native drought tolerant traits using marker assisted selection (Butzen and Schussler, 2009)
Conventional breeding
Dry soil = poor nutrient uptake Drought alters the root:shoot ratio Increased root respiration, increases
nutrient solubility More root respiration, has the potential to
increase nutrient uptake (Liu et al., 2004)
WUE x NUE interaction
http://www.monsanto.com/newsviews/pages/bt-corn-performance-in-us-corn-belt.aspx
Objective Evaluate N use efficiency (NUE) and water
use efficiency (WUE)◦ Drought tolerant and less drought tolerant
corn hybrids ◦ Irrigated and rainfed production systems
Experiment sites
LCB Efaw Established in 2013 and will continue in 2014
3 replicates 4 row plots, 6.1 m long Soils:
◦ Efaw Norge: Fine-silty, mixed, active, thermic Udic
Paleustolls◦ Lake Carl Blackwell (LCB)
Port: Fine-silty, mixed, superactive, thermic Cumulic Haplustolls, Oscar: Fine-silty, mixed, superactive, thermic, Typic Natrustalfs
Genetics ◦ Drought tolerant
Pioneer P1498: Optimum AQUAmax Monsanto 63-55: Droughtgard
◦ Less drought tolerant Pioneer P1395 Monsanto 62-09
Environment x Management
Experimental design: GxExM
Photo Courtesy of Jacob Bushong
◦ Rainfed production system Preplant N rates
0, 67, and 134 kg ha-1
Seeding rate 53,800 seeds ha-1
◦ Irrigated production system Preplant N rates
0, 101, and 202 kg ha-1
Seeding rate 75,650 seeds ha-1
Treatment Structure◦ Two way factorial with
4 levels of hybrid 3 levels of N rate
◦ Randomized complete block design◦ Nested within
production system SAS PROC GLM
◦ Analysis conducted by site and year
Statistical analysis
Grain yield and nitrogen use efficiency
(NUE) Grain yield (Mg ha-1)
◦ Center two rows per plot◦ Adjusted to 155 g kg-1 moisture
NUE (kg kg-1)◦ Grain yield kg ha-1 /
kg ha-1 applied N fertilizer
http://web.extension.illinois.edu/nwiardc/eb270/20121015_6040.html
Water use efficiency (WUE) Cumulative WUE (kg m-1)
◦ Grain yield kg ha-1 / Evapotranspiration (ET; m) ET = +∆SWC + R + I – D
◦ Soil Water Content (SWC) Preplant and postharvest 1 m soil profile
◦ Rainfall (R) Mesonet
◦ Irrigation (I)◦ Drainage (D)
negligible
Photo Courtesy of Tracy Wilson
March
April May Jun
e July
Augu
st
Septe
mber
0
5
10
15
20
25
30
Long Term2013
Rain
fall
(cm
)Rainfall
Main effects and interaction effects for grain yield, water use efficiency (WUE), and nitrogen use efficiency (NUE) at Efaw and Lake Carl Blackwell (LCB), 2013.
Efaw LCBGrain Yield WUE NUE
Grain Yield WUE NUE
------------------- Pr > F -------------------Irrigation 0.002 0.008 0.006 0.001 0.001 0.005Hybrid 0.297 0.248 0.301 0.292 0.351 0.566N Rate 0.722 0.700 0.004 0.017 0.016 0.007Irrigation x Hybrid 0.529 0.507 0.897 0.705 0.765 0.962Irrigation x N Rate 0.503 0.570 0.231 0.027 0.026 0.012Hybrid x N Rate 0.795 0.810 0.531 0.684 0.664 0.844Irrigation x Hybrid x N Rate 0.084 0.074 0.367 0.548 0.501 0.698
Analysis of variance
Efaw - I
rrigate
d
Efaw - R
ainfed
LCB -
Irriga
ted
LCB -
Rainfed
0123456789
10
Low NMed NHigh N
Grai
n Yi
eld
(Mg
ha-1
)Grain Yield
Single degree of freedom contrasts and differences of the means for grain yield (Mg ha-1), water use efficiency (kg m-1; WUE), and nitrogen use efficiency (kg kg-1; NUE) at Efaw, 2013.
Grain Yield (Mg ha-1)
WUE(kg m-1)
NUE(kg kg-1)
P > F Diff. P > F Diff. P > F Diff.Drought tolerant vs. Less drought tolerant 0.416 -0.485 0.503 0.314 0.361 -5.44
Monsanto vs. Pioneer 0.110 0.994 0.085 0.582 0.204 7.69
Droughtgard vs. AQUAmax 0.116 1.38 0.079 1.06 0.100 14.4
Hybrid differences: Efaw
Single degree of freedom contrasts and differences of the means for grain yield (Mg ha-1), water use efficiency (kg m-1; WUE), and nitrogen use efficiency (kg kg-1; NUE) at Lake Carl Blackwell (LCB), 2013.
Grain Yield (Mg ha-1)
WUE(kg m-1)
NUE(kg kg-1)
P > F Diff. P > F Diff. P > F Diff.Drought tolerant vs. Less drought tolerant 0.928 0.084 0.837 0.012 0.839 1.10
Monsanto vs. Pioneer 0.065 0.832 0.084 0.107 0.179 7.58
Droughtgard vs. AQUAmax 0.139 0.916 0.170 0.116 0.275 8.58
Hybrid differences: LCB
0 20 40 60 80 100 120 1400
0.5
1
1.5
2
2.5
Irrigated - High N Linear (Irrigated - High N)Rainfed - High N Linear (Rainfed - High N)
NUE (kg kg-1)
WUE
(kg
m-1
)NUE x WUE: Efaw
0 20 40 60 80 100 120 1400
0.5
1
1.5
2
2.5
Irrigated - High N Linear (Irrigated - High N)Rainfed - High N Linear (Rainfed - High N)
NUE (kg kg-1)
WU
E (k
g m
-1)
NUE x WUE: LCB
Irrigation significantly increased grain yield, WUE, and NUE at both sites
Increased N rates resulted in higher yields for the irrigated production systems
Regardless of hybrid, improvements in WUE resulted in increased NUE
The Monsanto Droughtgard hybrid yielded ~1 Mg ha-1 more than the Pioneer AQUAmax hybrid at both sites (~$70)◦ Lack of drought tolerant hybrid differences in 2013
could have been from an unseasonably wet growing season
Conclusions
Questions?