1. Dr. Dave Hooker
University of Guelph Ridgetown Campus
Email: dhooker@uoguelph.ca
Dr. Bill Deen
University of Guelph, Dept. of Plant Agriculture
@cropdoc2
Can Crop Management Improve
Environmental Stress Tolerance?
2. Declining Crop Diversity in Ontario, 1981-2013
(Ontario Ministry of Agriculture, Food and Rural Affairs, Field Statistics 2014)
Harvested areas (hectares) of major field crops shown as % of total harvested area from 1970 to 2014 for Ontario.
(Source: Statistics Canada, 2016.) (Reproduced from Deen et al., 2016)
6. Image of an old farmstead
• yield improvement
• nitrogen supply
• weed, disease and insect management
• integration with livestock
• labour distribution
• risk mitigation
• soil quality enhancement
“Past” Reasons for Crop Rotation
@cropdoc2
7. Drivers of rotation change – “past” to “present”
• Synthetic fertilizers
• Herbicides, insecticides, fungicides
• Improvements in crop genetics – e.g. GMO
• Specialization and separation of crop and livestock
production
• Increase in equipment size
• Government programs
• Market demand
• %age of rented land Source: Bill Deen (UG)
@cropdoc2
8. • Crop rotation diversity vs.
• corn and soybean yield?
• N requirements for corn?
• Soil quality?
• Economics?
• Impact of cover crops in the long-term?
Questions only for long-term studies
24. Rotation effect on soybean yield: Elora 1982-2012
2000
2200
2400
2600
2800
3000
3200
CCSS CCSW CCSWRC
Soybeanyields(kgha-1)
CS CSW CSWrc
a
b b
a
b b
Tilled NT
Deen (UG)
(36)
(42)
25. First Year Soybean Yield: Elora rotation trial 1982-2013
Moldboard plow
Reduced-till/NT
Source: Deen (2017)
26. Impact of crop rotation diversity in future years with
greater weather extremes?
31. Crop Rotation and Stress Reduction
How much can you impact the water supply to your crop?
@cropdoc2
32. <Cold/wet years
Hot/dry years
High yielding years
<Cold/wet years
Hot/dry years
@cropdoc2
CSW
CSWrc Hot/dry years
Hot/dry years
High yielding years
High yielding years
33. CSW
CSWrc
< Cold/wet years
Hot/dry years
< High yielding years
< Cold/wet years
Hot/dry years
< High yielding years
Hot/dry years
Hot/dry years
@cropdoc2
34. Evidence that water is becoming more limiting
Metrics
• Yield stability: “downside risk”
• Yield volatility: “temporal yield variability”
@cropdoc2
35. Evidence that water is becoming more limiting
Metrics
• Yield stability: “downside risk”
• Yield volatility: “temporal yield variability”
• Elora and Ridgetown corn and soybean yields unstable in hot, dry
summers (Gaudin et al. PLOSone, 2015)
• In 4 US States (IL, MI, MN, PA) 2000-2014 (Williams et al. PLOSone, 2016)
• drought and heat lowered yields and increased instability/volatility
• Soil water holding capacity buffered weather effects
• SOM and yield stability strongly correlated (Pan et al. 2009; Congreves et al 2016)
@cropdoc2
38. Change in SOM from 2002-2016
All Ontario vs. Essex, Lambton, Kent Counties
12,300-23,100
samples per year
SOM Trend in Ontario 2002-2016: 12-23K samples/year
Data from Jack Legg
(SGS Labs); compiled
by Brown (OMAFRA)
39. 15-yr trend for Essex, Lambton,
Kent Counties; 0.8% decline =
16,000 lbs/ac less SOM
Data from Jack Legg
(SGS Labs); compiled
by Brown (OMAFRA)
Change in SOM from 2002-2016
All Ontario vs. Essex, Lambton, Kent Counties
12,300-23,100
samples per year
SOM Trend in Ontario 2002-2016: 12-23K samples/year
40. Economics of a diverse rotation
-- it’s more complicated than you may think --
41. • Input costs - 2017 Field Crop Budgets, OMAFRA, 2017
• P and K by crop removal
• NPK costs – 2013-2017 Crop Input Surveys
• Crop prices: 2012-2015 OMAFRA Field Crops Statistics
• Straw removed: yield, price and P and K removal cost estimated
• All costs and prices adjusted to 2017 CDN$
Economic analysis assumptions
@cropdoc2
Source: Deen (2017)
42. Conventional Tillage Reduced Tillage
+
CCCC $2,519 $2,387
CCSS $2,137 $2,323
CCSW $2,744 $3,047
CCSW(rc) $2,980 $3,122
C – corn, S – soybeans, W – winter wheat, (rc) – underseeded red clover.
*Oats replaced first year barley in the spring cereal rotations starting in 2000.
+
Average revenue by rotation (1982-2013), in $ ha
-1
.
$799$843
Source: Deen (2017)
43. $843/ha greater net return for plowed CCSW(rc) compared to CCSS
• Yes but….
– Not everyone can sell straw - $350/ha
– Red clover does not always establish
- Lose N credit - $102/ha
- Lose soybean yield increase - $26/ha
- Lose corn yield increase - $27/ha
– A shorter season soybean is required - $60/ha
– CCSS not the same as CSCS - $123/ha
Total deductions - $688/ha
Source: Deen (2017)@cropdoc2
=$155/ha ?
44. • BUT…….
- Other cover crops than red clover ??/ha
- Grazing/forage opportunities of cover crops ??/ha
- Herbicide resistance management improved ??/ha
- More opportunity to sustainably sell crop residue ??/ha
- More timely seeding of corn and soybean ??/ha
- Future rotation benefit may be much larger ??/ha
- Increased potential for environmental service ??/ha
CCSW(rc) net return is (only) $155 greater than CCSS
Source: Deen (2017)@cropdoc2
47. Corn Soybean Wheat
Marginal yield
increase
+10 bu/ac +5 bu/ac
$/bu $4.50/bu $13.00/bu
Crop value
increase
$45/ac $65/ac
+ N credit $35/ac $0
Marginal rev $80/ac $65/ac $145/ac
In equivalent wheat yield @ $5.50/bu +26 bu/ac
OR in equivalent wheat price @ 90 bu/ac +$1.61/bu
48. Submitted: Assessing long-term historical and future trends in corn yields and soil carbon under diversified crop rotations. Jarecki et al. (2017)
Future
trends in
corn yields
vs. rotation
37 bu/ac diff
CCSS vs CSW
64 bu/ac diff
CCSS vs CCSW
49. Long-term trials show corn-soybean rotations:
• Reduce yield and causes greater yield instability
• Lower soil organic matter/poorest soil structure
• Increase N requirement for corn
• Reduces opportunity to incorporate cover crops
• Reduces opportunity for sustainable biomass removal
• Reduces profitability
Meyer-Aurich et al, 2006a; Meyer-Aurich et al 2006b; Sanscartier et al, 2013; Munkholm et
al, 2012; Munkholm et al, 2013; Muellera et al, 2009; Gaudin et al, 2013; Gaudin et al. 2014;
Gaudin et al. 2015, Kludze et al. 2013.; Van Eerd et al.. 2014
Source: Deen (2017)
@cropdoc2