Thomas Akin, State Resource Conservationist, USDA Natural Resources Conservation Service Cover cropping is a soil health-building practice gaining currency in cropland agriculture but also well suited to improving urban soils. Soil-incorporated cover crops provide large volumes of soluble carbon, the best fuel for the soil food web. Tom Akin gives a brief introduction to suitable cover crops to improve urban soils. Presented at the Urban and Suburban Carbon Farming to Reverse Global Warming conference at Harvard University on May 3, 2015, organized by Biodiversity for a Livable Climate. www.bio4climate.org

1. Tom Akin, State Resource Conservationist
USDA NRCS, Amherst, MA
Thomas.akin@ma.usda.gov

2. 1. Keep the soil
covered;
2. Keep a living root in
the soil year round;
3. Minimize
tillage/disturbance;
4. Increase plant
diversity (rotations
AND…
COVER CROPS! )

3. Soil
Soil organic matter
1-6% of total soil mass
Soil microbial biomass
3-9% of total SOM mass
Minerals
Stable (humus)
70-90%
Readily
decomposable
7-21%
Fungi
50%
Bacteria &
actinomycetes
30%
Yeast,
algea,
protozoa,
nematodes
10%
Animals
10%
“Building Soils for Better Crops”, Magdoff and van Es, 2000

6. Soil Aggregate

8. USDA NRCS NH

9. Prevent soil erosion;
Add organic matter;
Suppress weeds; (smother/outcompete);
Nitrogen (80-120 #/acre) from legumes;
Scavenge nitrogen from growing season;
Suppress diseases (biofumigants).

10. Spring (as early as possible!)
• Oats and peas
Summer
• Buckwheat +/- clover
• Japanese Millet/Red Clover or Sorghum
Sudangrass
• Oats and peas
Fall
• Crimson Clover (Sept 15)
• Winter Rye (By October 20)
• Hairy Vetch plus Winter Rye (By October 1)
• Austrian Winter Peas (By October 1)

11. Cornell University Organic Cropping
Systems Project

13. Cornell University Organic Cropping
Systems Project

14. Planted Sept 24th
Pictured May 08th
Hooks, C.R. , et al. 2012. J. App.
Entomology. University of Maryland

16. Cornell University
Organic Cropping
Systems Project

17. Terminated
In Late May
Terminated
In Late April
C:N Ratios

18. Cornell University Organic Cropping
Systems Project

19. AFTER MATURE RYE AFTER CLOVER
Cornell University Organic Cropping
Systems Project

20. Feed Them!