The Organic horticulture production system

1. The Organic Horticulture
Production System
Heather Friedrich
University of Arkansas
heatherf@uark.edu

2. Organic Production Principles
Defined according to the National Organic
Program (NOP) as:
an ecological production management system that
promotes and enhances biodiversity, biological
cycles and soil biological activity. It is based on
minimal use of off-farm inputs and on management
practices that restore, maintain and enhance
ecological harmony.
Production is based on a holistic biological
system & not input substitution
Soil based system

3. Organic Production Principles
Management-intensive: Routine observation of
plant health & weeds
Rule of Thumb: No synthetic fertilizers or
pesticides (including urea or Round-Up™); few
exceptions eg. pheromones
Rule of Thumb: Only naturally based products,
few exceptions eg. lead, arsenic, nicotine
No GMO seeds or irradiated products

4. “Feed the soil to feed the plant”
Build/maintain healthiest soil possible
through:
Crop rotation including cover crops
Tillage
Fertilizers
Mulch
Irrigation
Weed management
Insect, Arthropod & Disease management

5. What goes on in the soil that is so
important?
Elaine R. Ingham The Soil Biology Primer

6. Soil Fertility Management
Compost: animal-based
provides more N
Manure: cannot be applied
less than120 days prior to
harvest for a food crop
Cover crops: Legume/Grass
mixtures
Fish emulsion, seaweed
Plant based fertilizers
Alfalfa meal
Soybean meal
Field pea-oat-mustard cover
crop
Soil food web!!

7. Benefits of Compost
Nutrient recycling
cornerstone of ecologically-based farming
Assists in moisture retention in soils
Slow-release of nutrients
May reduce disease incidence due to an
increase of microbial populations
• may out-compete disease causing
organisms

8. Benefits of Compost
•Helps reduce odors of
original feedstocks
•Destruction of weed seeds
and pathogens
•Destruction of potentially
harmful microorganisms
such as E.coli 0157:h7 or
salmonella

9. Compost Rules for Organics
Can be applied to a crop at any time if it was
composted according to NOP rules:
Made with plant or animal materials
No biosolids or any other unapproved inputs (refer to
National List)
C:N ratio of 15:1 to 40:1
In-vessel or static aerated pile system must reach a
minimum of 131F for at least 3 days
A windrow system must reach at least 131F for 15
days and be turned at least 5x so that that all
materials reach temp
must be cured or aged
If compost does not meet standards, follow the same
rules as raw manure

10. Crop Rotations – annual crops
Rotation must include a cover crop and work to
maintain or improve soil organic matter
Consider crop nutrition, soil fertility
Interrupt insect, weed and disease cycles
Pests unable to find hosts when crops are changed
Change the crop ecology: shallow/deep roots,
cold/warm season, row/drilled crops, foliage density,
heavy/light feeders

11. 10 Year Rotation Scheme
Alex and Betsy Hitt, Chapel Hill NC; http://www.ssawg.org/hitt.html
Y
R
Spring Summer Fall
1 Tomatos & leeks Oat-crimson clover
2 Flowers-cool seas. Sudangrass-soyb. Oat-crimson clover
3 Spring lettuce Flowers, summer Rye-hairy vetch
4 Squash Fall planted flowers
5 Flowers-overwintered Sudangrass-soyb. Rye-hairy vetch
6 Peppers Wheat-crimson clover
7 Flowers -summer Oat-crimson clover
8 Mixed spring veg cowpeas Fall planted flowers
9 Flowers-overwintered Sudangrass-soyb. Oat-crimson clover
10 Flowers-summer Wheat-hairy vetch

12. Planting Diversity
Efficiency:
space
soil
water
reduces insects pressure
increases beneficial insects
Early season spring greens and garlic

13. Mixed lettuce
greens & gladiolas

14. Perennial Crops
Soil building & Biodiversity
Groundcover
management – mixed
spp
Mulches
Cover crops in strips
Insectary plantings

15. WEEDS
Understand the biology of
weeds:
annual, fixed perennial, wandering
perennial, the lifecycle,
establishment
Good soil for crops = good for
weeds
Action
Remove or Prevent establishment --
change the environment
“Many little hammers approach”

16. WEEDS! “Little Hammers”
Crop rotation & cover crops
-remember crop ecology
Cultivation (timely): hand-
hoe, rototilling, cultivators,
hoeing - dust mulch
Mulches: straw, fabric,
wool, flax, plastic (landfill
issues)
Flamer
Organic herbicides
Biodiversity: insects,
animals eat weed seeds

17. Mechanical Weed Control
Cultivation (timely&shallow): hoe,
cultivators - dust mulch
Push-pull hoes
ergonomic handles
Hand scrapers and cultivators for tight
spaces
Rototilling, multivators, tine & basket
weeders – can get close and in-btw
plants
Exhaust root system (perennial
weeds)– deplete storage reserves
Requires 6-8 timely treatments in yr 1, then
3-5 the following year

18. Tillage & Soil Health
Criticism of organic agriculture is use of tillage
Negative effects of tillage, offset by the use of
cover crops and additions of organic matter
(compost, manures, mulch, etc)
USDA-ARS research showed organic methods
can increase Organic Matter more than
conventional no-till
Must use caution against excessive tillage

19. Mulches
•Prevent seeds from germinating, can
smother out some weeds
•Conserve water, minimal soil
disruption,
•Use local resources: straw, fabric,
wood, newspaper, plastic/landsc. fabric
•Be careful of weed seeds in straw
•Especially good for perennial systems:
blueberries, blackberries, flowers, trees
•Living mulches – eg plant fall clover
crop, mow at flowering to kill it, plant
into residue

20. Paper mulch in lilies &
snapdragons
Rowcover over tomatoes
and landscaping fabric
between rows

21. Wood chip mulch laid over
newspapers in walk way
leaf mulch applied in fall to
perennial flowers
Wood chip mulch,
possibly free resource

22. Other methods of weed control
Organic herbicides
Matran, Burnout II, Green
Match, others
Phytotoxic – burn plant tissue
Thoroughly coat weed
Non-selective
•Flamer – especially handy during wet
conditions – no mechanical tools
•Broadleaf weeds more susceptible to flaming

23. Crop selection
Some crops are more competitive against
weeds than others
Rapid germination, growth, dense canopy
Use transplants vs direct seeding for crops if
possible
Transplant or plant into a clean bed
Allow a flush of weeds to emerge then till under

24. Insect – Weed
Interaction

25. Cover crops in Weed Management
How do they work?
• Smother weeds by out competing: light, water,
nutrients
• Release allelopathic chemicals that suppress
weed germination
• As they decompose, abundant microbial
communities suppress germination
• prevent soil erosion
• aka – “green manure”
• Recycle and scavenge nutrients
• Provide organic matter

26. Cover crops
How to incorporate into annual rotation
Time & Space niches
Time - plant cover crop before or after harvest
of main crops (eg. plant buckwheat between
spring greens and fall tomatoes)
Space – plant low growing cover crop within
main crop, after establishment (eg. plant
legume into sweetcorn)

27. Cover crops for Southeast
Winter cover crops –
plant in Fall
Hairy vetch
Crimson clover
Subterranean clover
Austrian winter pea
Grain rye, wheat, oats
Brassicas (radish, turnip)
Summer cover crops –
plant after frost
•Annual lespedeza
•Soybeans
•Southern peas
•Buckwheat
•lespedeza
•Sorghum-Sudangrass
Crimson clover

28. Insect Management
Crop rotation – healthy soil
Enhance natural plant defenses
Prevention - clean up after harvest &
destroy all infested fruits/vegetables
Row covers - keep pests out; put over
plants when young and remove at flowering
Companion planting and trap crops
Harvest early – variety selection
Know your pest--life cycle, natural enemies,
relationship with climatic conditions--and
manage at vulnerable period

29. Biological Control
Critical component of organic
insect management
Natural enemies (predators,
parasites, nematodes and
pathogens) exist for nearly every
pest
Conservation of beneficials is
key
Augmentation (purchased
beneficials) can work in certain
cases (e.g. greenhouses)
Trichopoda pennipes
Michigan Field Crop and Pest Ecology and Management , 2000

30. Conservation of Beneficials
Maintain adequate supply of
food (prey, pollen, nectar)
through plant diversity in the
farm landscape
Insectary plants: buckwheat,
clovers, herbs-dill, mint, yarrow;
flowers- gaillardia, allysum,
daisies
Use of toxic pesticides limited
to outbreaks

31. Approved Treatments
Use as last resort--may affect beneficials
Check with Certification Agency
Check with National List
Check with Organic Materials Review Institute
(OMRI) www.omri.org
Bacillus thuringiensis (Bt), lepidopteran
specific
Botanical insecticides: pyrethrum, sabadilla,
neem
Other natural treatments: D.E., garlic, hot
pepper, vegetable oils and soaps

32. Disease Management
Susceptible host
Favorable
environment
Virulent
pathogen
Disease Triangle: for disease to occur, all
3 must be present

33. Disease Management
Crop rotation – healthy soil
Disease resistant/tolerant cultivars; breeding
programs
Pruning & spacing- promote air-flow
Removal of diseased leaves/plants - sanitation
Compost application; compost tea
Organic fungicides – baking soda, garlic,
milk – efficacy dependant on several things
Serenade Bacillus subtilis –
powdery mildew, early & late
blight, gray mold

34. Compost for Disease Suppression

35. Organic Breeding
Seed breeding under organic
conditions
Organic Seed Alliance, Abundant
Life, Save Our Seeds, Cornell -
Public Seed Initiative, Seeds of
Change
Organic producer involvement
Organically bred varieties can thrive
under less than optimum conditions -
seedling vigor, efficient nutrient
uptake
Have multiple gene resistance -
cuticle thickness, trichomes, phenols

36. Resources
NCAT-ATTRA,
www.attra.org
Ag groups: SSAWG
Annual conf
Resources
www.ssawg.org/ed-resources.html
Local Extension office
Field days
Local Farmers Market
Internet
www.attra.org
www.ams.usda.gov/nop/indexIE.htm
www.extension.org
www.ofrf.org ; Organic Farming Research
Foundation

37. Acknowledgements
This presentation address general organic production practices. It is to be
to use in planning and conducting organic horticulture trainings. The
presentation is part of project funded by a Southern SARE PDP titled
“Building Organic Agriculture Extension Training Capacity in the
Southeast”
Project Collaborators
• Elena Garcia, University of Arkansas CES
Heather Friedrich, University of Arkansas
Obadiah Njue, University of Arkansas at Pine Bluff
Jeanine Davis, North Carolina State University
Geoff Zehnder, Clemson University
Charles Mitchell, Auburn University
Rufina Ward, Alabama A&M University
Ken Ward, Alabama A&M University
Karen Wynne, Alabama Sustainable Agriculture Network