finding the best fit
DESCRIPTION
This presentation was shared on 1/6 at the IL Specialty Crops, Agritourism and Organic ConferenceTRANSCRIPT
Finding the best fit cover crops on your
organic farm
Dr. Joel Gruver
WIU – Agriculture
crop rotationsHistorically
revolved around LEGUMES
A typical view 50 years ago
Typical rural landscape
in IA and IL today
>90% of landsurface
in corn or soybeans
Typical amounts of nitrogen
fixed by legumes
Alfalfa 150-300+
Soybeans 150-250
Red clover 75-200
Hairy vetch 75-200
Other annual forage
legumes50-150
(lbs/ac/yr)
Soybean seeds
normally contain
25-50% more N
than was fixed
within their
nodules
Hairy Vetch3,260 lbs of DM/ac
141 lbs of N/ac
133 lbs of K/ac
18 lbs of P/ac
52 lbs of Ca/ac
18 lbs of Mg/ac
http://www.ncl.ac.uk/tcoa/files/breakcrops_orgagr.pdf
Finding the best fit for CCs within a crop rotation
:
3 broad goals of
ecological
managementActivation
AugmentationConservation
Terminating spring planted oats with a soil finisher
~ 3 weeks before planting corn
GOAL = biological activation
• Problems and opportunities for over 500 crop
sequences
• Characteristics of more than 60 crops and 70 weeds
• Crop diseases hosted by over 80 weed species
• Modes of transmission for 250 diseases of 24 crops
• Thirteen sample four- and five-year vegetable and
grain crop rotations Managing Crop Rotation Chart
with key tasks & steps
•Sample worksheets and calculations
• Step-by-step procedure for determining crop rotation
plans
Overview of book contents
Rotations
should evolve
not revolve
• Fast germination and emergence
• Competitiveness
• Tolerance to adverse climatic & soil
conditions
• Ease of suppression/residue
management
• Fertility/soil quality benefits
• Low-cost
What to Look For in A Cover Crop
Cover
Crops
Adapted from Magdoff and Weil (2004)
Cover crops have many effects!
Feed
livestock
? ?
Increase
management
Host
pests
Become
a weed
Prevent
soil
drying
Dry out soil
excessively
Interfere w/
equipment
performanceSuppress
crop growth
Tie up N
Add cost
Cover
Crops
Adapted from Magdoff and Weil (2004)
Not all are positive
Grazing brassicas, clovers, small grains, ryegrass, sorghum-sudan
Nutrient Cycling brassicas, small grains, annual ryegrass
Bio-drillingbrassicas, sugarbeet, sunflower,
sorghum-sudan sweet clover, alfalfa
N-fixation clovers, vetches, lentil, winter pea, chickling vetch, sun hemp,
cowpea, soybean
Bio-activation/fumigation brassicas, sorghum-sudan, sun hemp, sesame
Matching specific objectives with species
How will I seed the cover crop?
What will soil temperature and moisture conditions be like?
What weather extremes and field traffic must it tolerate?
Will it winterkill in my area?
Should it winterkill to meet my goals?
What kind of regrowth can I expect?
How will I kill it and plant into it?
Will I have the time to make this work?
What’s my contingency plan—and risks—if the
cover crop doesn’t establish or doesn’t die on schedule?
Do I have the needed equipment and labor?
Key considerations
Start planning now for next fall!
Best single source of info on cover crops is FREE!
regularly updated blog on
cover crop management
There are lots of opportunities following small grains!
Hu
nte
r
Have you tried any forage brassicas?
#1
opportunity
to make
cover crops
pay
Hairy vetch can be successfully planted after
wheat harvest. On the two occasions (out of 18
site-years of the WI Cropping System Trial)
when the red clover failed to establish well,
hairy vetch produced an average of 115 lbs N/a
providing an excellent ―back-up plan‖.
July/August plantings of vetch or
other cover crops are riskier than
frost seeding clover.
the most tried and true
cover cropping system
in the Midwest region
Frost-seeded clover
Sweet
clover
Mustard
http://calshort-lamp.cit.cornell.edu/bjorkman/covercrops/spring-mustard.php
Klaas and Mary Martens,
organic innovators in
Central NY State, are
reporting excellent results
with frost-seeded
confectionary mustard
ahead of dry beans
Be realistic about potential
cover crop challenges
Are you equipped to handle a situation like this?
10’ Howard Rotavator tilling ~ 3” deep with C blades
Complete kill after 1 pass
and 2 days of sun
Typical weather in 2009/2010 :-<
Where are the soybeans??
Traditional organic weed management
often comes up short during wet years
A strong stand of cereal rye was incorporated
~ 2 weeks before these soybeans were planted
Organic No-till?
Rodale roller
Cultimulcher
Less
weed seed
germination
…but few
options for
weed
termination
Early July 2009
Early August 2009
Early November 2009
Plot yields ranged from 51.6 to 58.6 bu/ac
No significant differences between systems
November 2010
Plot yields ranged from 42-52 bu/ac
Significant foxtail pressure
but almost no broadleaf weeds
Soybean health experiment – 6 locations across IL
Mustard
Rapeseed
Canola
Cereal rye
November 2010
Bio-strip till
September 2008
Attempt #2September 2009
Tillage radish on 30” rows with oats on 7.5” rows
November 2009
Radish planted on 30‖ rows using milo plates
in mid-August 2010
Ontario, Canada
Radish planted in
volunteer cereal rye
November 2010
Annual ryegrass variety trial
November 2010
Annual ryegrass
w/crimson clover
Wheat + radish trial
November 2010
What is a cover crop cocktail??
Sunflowers + soybeans+ buckwheat
July 17 planting
July 29 planting
Cover crops generally require more management
than manure or purchased nutrient amendments
Many of the 2008
profiles were
updated in 2010!