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The Organic Horticulture Production System. Heather Friedrich University of Arkansas heatherf@uark.edu. Organic Production Principles. Defined according to the National Organic Program (NOP) as:
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The Organic Horticulture Production System Heather Friedrich University of Arkansas heatherf@uark.edu
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 & 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
“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
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 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 Soil food web!! Field pea-oat-mustard cover crop
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
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 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
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
10 Year Rotation SchemeAlex and Betsy Hitt, Chapel Hill NC; http://www.ssawg.org/hitt.html
Planting Diversity • Efficiency: • space • soil • water • reduces insects pressure • increases beneficial insects Early season spring greens and garlic
Perennial CropsSoil building & Biodiversity • Groundcover management – mixed spp • Mulches • Cover crops in strips • Insectary plantings
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”
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
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
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
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 Wood chip mulch, possibly free resource leaf mulch applied in fall to perennial flowers
Other methods of weed control • Flamer – especially handy during wet conditions – no mechanical tools • Broadleaf weeds more susceptible to flaming • Organic herbicides • Matran, Burnout II, Green Match, others • Phytotoxic – burn plant tissue • Thoroughly coat weed • Non-selective
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
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 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)
Cover crops for Southeast • Summer cover crops – plant after frost • Annual lespedeza • Soybeans • Southern peas • Buckwheat • lespedeza • Sorghum-Sudangrass Winter cover crops – plant in Fall • Hairy vetch • Crimson clover • Subterranean clover • Austrian winter pea • Grain rye, wheat, oats • Brassicas (radish, turnip) Crimson clover
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
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) Michigan Field Crop and Pest Ecology and Management , 2000 Trichopodapennipes
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
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
Disease Management Susceptible host Favorable environment Virulent pathogen Disease Triangle: for disease to occur, all 3 must be present
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
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
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
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 CESHeather 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