the organic system
TRANSCRIPT
The Organic Horticulture Production System
Heather FriedrichUniversity of Arkansas
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
Organic Production Principles
Management-intensive: Routine observation of plant health & weedsRule of Thumb: No synthetic fertilizers or pesticides (including urea or Round-Up™); few exceptions eg. pheromonesRule of Thumb: Only naturally based products, few exceptions eg. lead, arsenic, nicotine No GMO seeds or irradiated products
“Feed the soil to feed the plant”Build/maintain healthiest soil possible through:
Crop rotation including cover cropsTillageFertilizersMulch IrrigationWeed managementInsect, Arthropod & Disease management
What goes on in the soil that is so important?
Elaine R. Ingham The Soil Biology Primer
Soil Fertility Management
Compost: animal-based provides more NManure: cannot be applied less than120 days prior to harvest for a food cropCover crops: Legume/Grass mixturesFish emulsion, seaweedPlant based fertilizers
Alfalfa mealSoybean meal
Field pea-oat-mustard cover crop
Soil food web!!
Benefits of Compost
Nutrient recycling cornerstone of ecologically-based farming
Assists in moisture retention in soilsSlow-release of nutrientsMay reduce disease incidence due to an increase of microbial populations• may out-compete disease causing
organisms
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
Compost Rules for OrganicsCan be applied to a crop at any time if it was composted according to NOP rules:
Made with plant or animal materialsNo biosolids or any other unapproved inputs (refer to National List)
C:N ratio of 15:1 to 40:1In-vessel or static aerated pile system must reach a minimum of 131F for at least 3 daysA windrow system must reach at least 131F for 15 days and be turned at least 5x so that that all materials reach tempmust be cured or aged
If compost does not meet standards, follow the same rules as raw manure
Crop Rotations – annual crops
Rotation must include a cover crop and work to maintain or improve soil organic matter Consider crop nutrition, soil fertilityInterrupt insect, weed and disease cycles
Pests unable to find hosts when crops are changedChange the crop ecology: shallow/deep roots, cold/warm season, row/drilled crops, foliage density, heavy/light feeders
10 Year Rotation SchemeAlex and Betsy Hitt, Chapel Hill NC; http://www.ssawg.org/hitt.html
YR
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 flowers5 Flowers-
overwinteredSudangrass-soyb.
Rye-hairy vetch
6 Peppers Wheat-crimson clover7 Flowers -summer Oat-crimson clover8 Mixed spring veg cowpeas Fall planted flowers9 Flowers-
overwinteredSudangrass-soyb.
Oat-crimson clover
10
Flowers-summer Wheat-hairy vetch
Planting Diversity
Efficiency: space soilwater reduces insects pressure increases beneficial insects
Early season spring greens and garlic
Mixed lettuce greens & gladiolas
Perennial CropsSoil building & Biodiversity
Groundcover management – mixed sppMulchesCover crops in stripsInsectary plantings
WEEDSUnderstand the biology of weeds:annual, fixed perennial, wandering perennial, the lifecycle, establishmentGood soil for crops = good for weeds
ActionRemove or Prevent establishment --
change the environment“Many little hammers approach”
WEEDS! “Little Hammers”
Crop rotation & cover crops-remember crop ecologyCultivation (timely): hand-hoe, rototilling, cultivators, hoeing - dust mulchMulches: straw, fabric, wool, flax, plastic (landfill issues)FlamerOrganic herbicidesBiodiversity: insects, animals eat weed seeds
Mechanical Weed Control
Cultivation (timely&shallow): hoe, cultivators - dust mulchPush-pull hoesergonomic handles Hand scrapers and cultivators for tight spacesRototilling, multivators, tine & basket weeders – can get close and in-btw plantsExhaust root system (perennial weeds)– deplete storage reserves
Requires 6-8 timely treatments in yr 1, then 3-5 the following year
Tillage & Soil HealthCriticism of organic agriculture is use of tillageNegative 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-tillMust use caution against excessive tillage
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
Paper mulch in lilies & snapdragons
Rowcover over tomatoes and landscaping fabric between rows
Wood chip mulch laid over newspapers in walk way
leaf mulch applied in fall to perennial flowers
Wood chip mulch, possibly free resource
Other methods of weed control
Organic herbicidesMatran, Burnout II, Green Match, othersPhytotoxic – burn plant tissueThoroughly coat weedNon-selective
• Flamer – especially handy during wet conditions – no mechanical tools• Broadleaf weeds more susceptible to flaming
Crop selection
Some crops are more competitive against weeds than others
Rapid germination, growth, dense canopyUse transplants vs direct seeding for crops if possibleTransplant or plant into a clean bed
Allow a flush of weeds to emerge then till under
Insect – Weed Interaction
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
Cover crops
How to incorporate into annual rotationTime & 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)
Cover crops for Southeast
Winter cover crops – plant in FallHairy vetchCrimson cloverSubterranean cloverAustrian winter peaGrain rye, wheat, oatsBrassicas (radish, turnip)
Summer cover crops – plant after frost• Annual lespedeza • Soybeans • Southern peas • Buckwheat• lespedeza • Sorghum-Sudangrass
Crimson clover
Insect ManagementCrop rotation – healthy soil Enhance natural plant defensesPrevention - clean up after harvest & destroy all infested fruits/vegetablesRow covers - keep pests out; put over plants when young and remove at floweringCompanion planting and trap cropsHarvest early – variety selectionKnow your pest--life cycle, natural enemies, relationship with climatic conditions--and manage at vulnerable period
Biological Control
Critical component of organic insect managementNatural enemies (predators, parasites, nematodes and pathogens) exist for nearly every pest Conservation of beneficials is keyAugmentation (purchased beneficials) can work in certain cases (e.g. greenhouses)
Trichopoda pennipes
Michigan Field Crop and Pest Ecology and Management , 2000
Conservation of Beneficials
Maintain adequate supply of food (prey, pollen, nectar) through plant diversity in the farm landscapeInsectary plants: buckwheat, clovers, herbs-dill, mint, yarrow; flowers- gaillardia, allysum, daisiesUse of toxic pesticides limited to outbreaks
Approved Treatments
Use as last resort--may affect beneficials Check with Certification AgencyCheck with National ListCheck with Organic Materials Review Institute (OMRI) www.omri.orgBacillus thuringiensis (Bt), lepidopteran specificBotanical insecticides: pyrethrum, sabadilla, neemOther natural treatments: D.E., garlic, hot pepper, vegetable oils and soaps
Disease Management
Susceptible host
Favorable environment
Virulentpathogen
Disease Triangle: for disease to occur, all 3 must be present
Disease ManagementCrop rotation – healthy soilDisease resistant/tolerant cultivars; breeding programsPruning & spacing- promote air-flowRemoval of diseased leaves/plants - sanitationCompost application; compost teaOrganic fungicides – baking soda, garlic, milk – efficacy dependant on several thingsSerenade Bacillus subtilis –
powdery mildew, early & late blight, gray mold
Compost for Disease Suppression
Organic BreedingSeed breeding under organic conditions Organic Seed Alliance, Abundant Life, Save Our Seeds, Cornell - Public Seed Initiative, Seeds of Change Organic producer involvementOrganically bred varieties can thrive under less than optimum conditions -seedling vigor, efficient nutrient uptakeHave multiple gene resistance -cuticle thickness, trichomes, phenols
ResourcesNCAT-ATTRA,
www.attra.orgAg groups: SSAWG
Annual confResources www.ssawg.org/ed-resources.html
Local Extension officeField daysLocal Farmers MarketInternet
www.attra.org www.ams.usda.gov/nop/indexIE.htm www.extension.org www.ofrf.org ; Organic Farming Research Foundation
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 ArkansasObadiah Njue, University of Arkansas at Pine BluffJeanine Davis, North Carolina State UniversityGeoff Zehnder, Clemson UniversityCharles Mitchell, Auburn UniversityRufina Ward, Alabama A&M UniversityKen Ward, Alabama A&M UniversityKaren Wynne, Alabama Sustainable Agriculture Network