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?