No-till combined with cover crops is revolutionizing North American agriculture and making it more regenerative on a large scale.

1. Ray Weil

2. 
Soil Health is Key to Sustainability:
Physical/Chemical/Biological
Cover Crops: Tools for sustainability
Ag Revolution: new interest in / applications
of soil health lead by “rock star farmers”
Positive Environmental Impacts: Carbon
sequestration, energy efficiency, cleaner
water, better food, fewer chemicals
Main Points

3. 
Farmer = Ecologist. Managing Millions of
“Moving Parts”:
both above and below ground
1. Plants: Crops , forages , green manures,
weeds.
2. Animals: Cattle, wildlife, soil fauna.
3. Microbes: Pathogens, soil food web
4. Physical /chemical environment: Weather,
soil structure, texture, pH, fertility.

4. 
Typical dung beetle in cow manure
Buries
manure
Conserves
Nitrogen and
other
nutrients
Keystone Species: a Dung Beetle

5. Earthworms - Ecological engineers
Photo by Steve Groff

6. Cover crop roots and anecic earthworms
under no-till: reconnecting topsoil and
subsoil
CANSIS

7. Soil core
Heat source
Cold water
The Actors: Meso-fauna

8. Bacterivore
Fungivore
Plant Parasitic
Nematodes play
diverse roles within
the food web
Omnivore
Predator
Photos: Lisa Stocking Gruver, U of Md
Plant parasite

9. The Soil Food Web Matters!
From Omay, et al. 1998.

10. Margaret McCully.
Wheat root covered with
rhizobacteria
Plant – microbe
partnerships

11. • Acid conditions
• Untilled soil - Residues on
surface
• Woody, resistant materials
Microorganisms: Fungi

12. 
Absorb, hold and release water
Breath -- exchange gases
Cycle nutrients - mineralization
Assimilate carbon into SOM
Resist raindrop erosion
Allow root penetration
Suppress pathogens
Sustain genetic diversity
A Healthy Soil Will….

13. 
Soils from the rotation plots after drying.
25 yrs of
conventional
tillage corn.
1.2 % SOM
20 yrs of
bluegrass, then 5
yrs conventional
corn. 2.0% SOM

14. 
Organic v Conventional: False Choice
The agricultural cropping efficiency (ACE)
The agricultural cropping efficiency (ACE) coefficient is defined as the total
sweet corn yield per unit of pollutant lost, with greater coefficient values
indicating higher yields with less pollution. Normalized to No-
Till/Conventional
SWEET CORN
PRODUCTION SYSTEM
(North Carolina)
ENVIRONMENTAL IMPACTS
EROSION
(SEDIMENT
LOSS)
TOTAL
PHOSPHORUS
TOTAL
DISSOLVED
NITROGEN
2011 2012 2011 2012 2011 2012
CONV TILL /Conventional 2b 6c 6c 17b 16b 24
CONV TILL /Organic 4b 10b 4c 9b 14b 44
NO-TILL /Organic 37a 16b 14b 11b 26b 33
NO-TILL /Conventional 100a 100a 100a 100a 100a 100
P value <0.001 <0.001 <0.001 <0.001 <0.05 >0.05
Edgell, J., D.L. Osmond, D.E. Line, G.D. Hoyt, J.M. Grossman, and E.M. Larsen. 2015. Comparison of surface water quality and
yields from organically and conventionally produced sweet corn plots with conservation and conventional tillage. J Envir Qual.

15. 
Planting
Cover crops can utilize
otherwise wasted resources
The sun shines, the rain falls and microbes work 10-12 months a year,
but this typical Indiana grain farm captures only 3-4 months of this
activity.
Harvest

16. 
Cover Crops Liberate Farmers from
Market Dictates on What to Plant
1. Cool season
grasses
2. Cool season
Legumes
3. Cool season
Brassicas
4. Warm season
grasses
5. Warm season
legumes
6. Warm season
broadleaves

17. Increased
infiltration
Soil Cover
Soil
organic
matter
Nematodes
Food
web
activity
Labile C
Soil
Aggregation
Nitrogen
fertility
Weed
suppression
Soil
water
Soil
temperature
Cover
crops
Enhanced
crop
growth
Bio-drilling
Reduced
erosion loss
Nutrient capture
(N, P, S, K, etc)
Rhizobial
associations
P- fertility
Reduced
evaporation
Reduced leaching
loss (N)
Mycorrhizal
associations
By increasing bio-diversity and keeping living roots in
the soil year-round ….

18. Following winter cover crop
No winter cover crop
Water dynamics: usually bio-drilling combined with
surface mulch can be a water life saver during summer!
Comparison on PA farm of
Steve Groff, a leading no-till
cover cropper.

19. Cover crops can
improve structure
deeper in the soil

20. Bouwman, L.A., and W.B.M. Arts. 2000. Effects of soil compaction on the relationships between
nematodes, grass production and soil physical properties. Applied Soil Ecology 14:213-222.
Compaction tripled plant parasite nematodes
(herbivores) but didn't change total nematodes
Reclaimed polder
with calcareous
sandy loam (30% silt,
5% OM) dug 60 cm
deep, compacted and
planted to perennial
ryegrass.

21. Investigating roots with fiber optic camera:
minirhizotron
Bio-drilling- the cover crop
answer to compaction

22. 45 cm2
Chen and Weil, unpublished
Roots of corn
following rye,
radish or no
winter cover
crop
Compacted
layer
Plow depth

23. Another major cover crop
function:
enhanced nutrient management
Reduce losses
Enhance availability
Add nitrogen
Recover deep nutrients

24. Nutrient capture:
nitrogen in fall

25. Unpublished data of Weill and Fisher
By March-April, radishes are long dead and its residue is
mainly gone, but its nitrogen capture effects are still evident.

27. 0
1
2
3
4
5
6
7
8
No cover Oat Radish Rad + Oat
Fresh
spinach,
Mg/ha
Roto tilled
No-till
16
14
12
10
8
6
4
2
0
Organic no-till,
no-herbicide
veggies using
cover crops
Lounsbury, N.P., and R.R. Weil. 2015. No-till seeded spinach after winterkilled cover
crops in an organic production system. Renewable Agriculture and Food Systems 30:1-13.

28. No-till corn, after radish cover crop
No-till corn, after rye cover crop
Nitrogen captured in fall can reduce the need
for fertilizer in spring

29. Example of more advanced cover cropping:
Zoned cover crop mixtures
Photo by Natalie Lounsbury

30. Thank-you!
Any questions?