1/14/2015

1

Organic Vegetable Production

2015 Small Farm SeriesJanuary 15, 2015

Danielle TreadwellAssociate Professor and State Extension Specialist, Organic Vegetable Production

Horticultural Sciencesddtreadw@ufl.edu

What you will learn today:

• Organic FACT or FICTION? (a quiz…just for fun)

• So what is organic, really?

• How the certification process works

• Soil Health, the cornerstone of success:

– Nutrient management

– Cover crop management

– Soil management

• Self‐assessment to determine if its “worth it”

Process of Certification

1/14/2015

2

Systems are Certified

Products Bear Organic Labels

Alleco.com

Matt’s Organics

Inputs Are Approved for Use

www.omri.org

1/14/2015

3

Production Condition ORGANIC NATURALEPA Registered Pesticides with “moderate “ or “high” risk

Not allowed Allowed

GMOs, Transgenic  Not allowed AllowedAntibiotics Allowed without 

USDA Organic labelAllowed

Growth hormones Not allowed AllowedMunicipal waste  or irradiation Not allowed AllowedAnimal welfare requirements Yes NoAudit trail from farm to table Yes NoCertification required, including inspections

Yes No

Legal restrictions on allowable materials

Yes No

How do I determine if a product is OK for organic production?

• Refer to the “National List”

• Look for OMRI label

• Look for NOP/EPA label

• Contact a county Extension specialist

• Contact Florida Organic Growers

– www.foginfo.org

The National List of Allowed and Prohibited Substances

• Allowable inputs are legislatively mandated• Lists generic materials that are compliant with the law, and those excluded from the law.

• Ultimately, the certification agency will provide final approval for use of any material input on the farm.

• Tends to encourage farmers to think in terms of specific materials as solutions to problems, rather than to think holistically. 

• See “Can I use this input on my organic farm?” for a more detailed explanation at: http://www.extension.org/article/18321

1/14/2015

4

Are there exemptions?

• Gardeners, by definition, are not required to be certified.

• Farmers grossing < $5,000/year are exempt from certification, but must still follow rule. 

• Objective is then to apply organic principlesand practices of organic farming systems to exempt farms/gardens.System Management

– Soil Management

– Cultural Management

Organic Begins with the Soil

Global Awareness Campaign for Soil Health

1/14/2015

5

Soil Health. What is It?

Soil Health is the continued capacity of the soil to function

as a vital living ecosystemthat sustains plants, animals, and humans.

• Physical 

• Biological

• Chemical

Soil Health. What is It?

‘FL401’ cereal rye and soil pit on Brock Farms

• Physical

• Biological

• Chemical

Soil Health. What is It?

‘FL401’ cereal rye living roots at a depth of 30 inches.

1/14/2015

6

• Physical 

• Biological

• Chemical

Soil Health. What is It?

Humic acid binds tightly with 1:1 clays like Kaolinite.

REDUCE TILLAGE

RETAIN RESIDUE

RETAIN ROOTS

RESTORE BIODIVERSITY

Soil Health Planning Principles – the 4 R’s

1/14/2015

7

What Happens to the Soil:

Tillage Impacts

• Destroys aggregates

• Exposes organic matter to decomposition

• Compacts the soil

• Damages soil fungi

• Reduces habitat for the Soil Food Web

• Disrupts soil pore continuity

• Increases salinity at the soil surface

• Plants weed seeds

No Tillage

• Soil pores remain continuous• Soil aggregates form and are 

not destroyed• Soil Food Web increases and 

diversifies• Weed seeds are not planted• Water is captured and stored• Bulk density decreases• Soil fungi and earthworms 

increase• Microarthropods increase 

(>20% of nutrient cycle)

Soil Organic Matter 

• Considered the single most important indicator of soil quality

Jessica’s Organic Farm, Bill Picher, Sarasota, FL

Organic vegetable system in St. Croix, USVI. Soil organic matter percent in the top 20 cm of soil following cover crop termination

but prior to incorporation

Organic matter (%) by cover crop rotationCC Year 1 CC Year2

Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5 Cycle 6

WF 4.9ab 4.9 3.4ab WF 3.5 2.7b 2.3

SS 5.5a 5.7 3.1b PM 3.3 2.5b 2.2

PM 4.4ab 5.4 3.9ab SS 3.5 3.1ab 2.6

VB 3.7b 6.7 3.9ab SH 3.7 3.4a 2.7

SH 4.5ab 5.9 3.8ab VB 3.7 2.9ab 2.6

SSVB 5.3ab 5.6 3.6ab SHPM 3.7 3ab 2.5

SHPM 4.5ab5.5 4.1a

SSVB 3.4 2.9ab2.6

Weiss et al., 2012

1/14/2015

8

CFR 205.203: SOIL FERTIITY & CROP NUTRIENT PRACTICE STND

The producer must (a) Select and implement tillage and cultivation practices 

that maintain or improve the physical, chemical and biological condition of the soil and minimize soil erosion

(b) Manage nutrients and fertility through crop rotations, cover crops, and the application of plant and animal materials

(c) Manage plant and animal materials in a manner that does not contribute to contamination, pathogens, heavy metal accumulation, or accumulation of residues 

Steps to an Organic Fertilization Program

1. Soil test2. Test bulk amendments for NPK3. Estimate N contribution from cover crops4. Apply IFAS recommended rates, regardless of

source5. Modify timing and method of application6. Rotate with other crops and cover crops7. Keep production beds free of weeds8. Manage irrigation to limit nutrient loss9. Estimate N,P,K crop removal and replace10. Select inputs approved for use in organic systems

Nitrogen Factories

• Autotrophic bacteria transform organic nutrients to mineral, plant available forms.

Nitrosomonas europaea uses ammonia to grow, and produces nitrite.Stan Watson, Woods Hole Oceanographic Institute

Nitrobacter winogradskyiuses nitrite to grow and produces nitrate that is later taken up by plants. 

W.J. Hickey, Univ. Wisconsin

1/14/2015

9

Popular/Allowable Fertilizers

• Compost• Animal manures• Plant manures (cover crops)• Commercially-available blended

dry granular or liquid fertilizers

• Animal and fish by‐products

• Potassium magnesium (K‐Mag) or Potassium magnesium sulfate (Sul‐po‐mag)

• Phosphorus typically sufficient in blended fertilizers

Dry Granular Fertilizer

• IFAS recommendations are that no more than 50% of the crop’s total nitrogen requirement be applied at the time of transplanting or seeding.

• If dry granular fertilizer is to be used throughout the season, consider that using plastic mulch will interfere with additional applications of dry granular fertilizer

• Because organic fertilizers are typically slow release, some farmers justify the application of greater than 50% of the total requirement at planting if using plastic mulch, and others simply avoid mulch completely.

Description  Manufacturer N‐P‐K Component Ingredients

Granular poultry Perdue 

AgriRecycle

4‐2‐3 Poultry litter

Granular composite Fertrell Company 4‐2‐4 Aragonite (a carbonate mineral), bone char, 

composted poultry manure, sodium nitrate, 

feather meal, greensand, peanut meal, sulfur and 

sulfate of potash

Granular meals Nature Safe

Industries

8‐5‐5 Feather, meat, bone and blood meals, sulfate of 

potash, yeast, sugars, carbohydrates and humus

Hydrolyzed fish  Hytech Foliar, 

Agro‐K Corp

5‐2‐2 hydrolyzed fish and seaweed [Ascophyllum

nodosum (L.) Le Jolis]

Organic Fertilizer Ingredients

1/14/2015

10

Liquid Fertilizer

• Expensive but effective• Can be high in salts, but many have

beneficial phytohormones and micronutrients (like seaweed, kelp)

• Follow label directions for application rates

• Applications can be made using a simple sump pump and bucket injected into a drip irrigation system, or can be hand watered in

• Look for products that have Chilean nitrate (sodium nitrate) for rapid solubility and plant root uptake, but take care not to increase soil sodium concentration over time with repeated use.

Animal Manures

• Raw Manure NOP 90/120 Day Rule*

• If manure does not touch edible portion, apply 90 days in advance of harvest

• If manure does touch, apply 120 days ahead

*National Organic Program, pending FSMA final rule

Compost

• Compost 

– Requires prolonged microbial activity to decompose materials

– Microbes need oxygen, moisture and “food”

– Carbon:Nitrogen ratio of raw materials should be 25:1 to 40:1 for rapid composting

– Temperature must reach 131º – 170º F to kill weed seeds and pathogens

• 3 days with static aerated

1/14/2015

11

Raw Materials

Materials approved for composting under the National Organic Program

– Newspaper or other recycled paper, without glossy or colored inks

– Worm castings

– Wood chips and shavings from untreated and unpainted wood only

– Food waste 

– Yard waste

Composting on Organic Farms

2 Main Approaches to Composting

1. Windrow System – raw materials are organized into windrows at least 3’ tall and 3’ wide, and maintain temperatures 131°F ‐170°F for 15 days + a minimum of 5 turns. 

2. Static or In‐Vessel – raw materials are organized into a cubic pile at least 3’ tall and 3’ wide, and maintain temperatures 131°F ‐ 170°F for 3 days

Using Compost Properly

• Special consideration should be given to compost used in school gardens, gardens for the elderly or sick.

• Look for compost that meets/exceeds standards established by the US EPA (code of federal regulation (CFR) 40 section 503) or the USDA’s National Organic Program. 

• The US Composting Council (USCC) offers a Seal of Testing Assurance (STA) that certifies the compost as pathogen‐free for fecal coliform bacteria. 

• EPA, DEP, and County and City regulations

• See EDIS CV118 for more info on commercial compost.

1/14/2015

12

Compost Tea

• Tea from raw manure is prohibited in organic systems

• Made by soaking or steeping compost in water.  

• Goal is to apply microorganisms to plants and soil. 

• Do not make tea from raw manure

• Does not consistently suppress pathogens http://www.finegardening.com/how‐

to/articles/brewing‐compost‐tea.aspx

Vermicomposting

• Intention is to create a mixture of raw materials and conditions to favor decomposition by worms.

• Redworms (Eisneia foetida) can transform up to 50% of their body weight into organic material a day.

• Layer bottom with brown bedding, and add food scraps to the top. Limit amount of food added to avoid temperature increases. 

• Read “Worms eat my garbage” by Mary Appelhof

Risks Associated with Compost

• Contamination– Enteropathogens  (Salmonella, E. coli, etc.)

– Herbicides (clopyalid – effective on legumes and nightshades, sold as Stinger, Confront and Curtail for lawns)

– Antibiotics (oxytetracycline in cattle)

• Improper Application– High rates of unfinished compost may limit plant growth and disturb soil fauna

1/14/2015

13

Cover Crops Roles in Diversity

1. Can be used to accelerate rejuvenating soil health

2. 6 to 8 weeks of cover crop growth is adequate to get benefits!

3. Will increase soil biological diversity: “Diversity above leads to Diversity below”

Cover Crops Retain N in the Soil

J. Luna, OSU, Corvallis

Monocultures

Neighbor's land use, previous and subsequent crop families very important.  Plant architecture and carbon form and content will influence termination method. 

1/14/2015

14

Polyculture (mixed) Species 

Polycultures reduce the period of time needed for soil biota to return to equilibrium but may differ in maturity rates, complicating termination plans. 

Conservation Agriculture

C. Palm et al., 2014. Conservation agriculture and ecosystem services: An overview. Agric. Ecosystems Environ. 187:87‐105

R. Lal. 2013. Enhancing ecosystem services with no‐till. Renewable Agric. Food Systems 28:102‐114

Defined: A system of agronomic practices that include reduced tillage or no tillage, permanent organic soil cover via crop residues, and crop rotation including cover crops. 

Soil Health Principle 3. RETAIN ROOTSGrow Living Roots Throughout the Year

• Increase microbial activity that influences N mineralization and immobilization

• Increase biodiversity and biomass of soil organisms

• Improve physical, chemical and biological properties of soils

• Sequester and redeposit nutrients

• Increase OMRye (Secale cereale) showing root growth in a NE silty clay loam to 5.2 ft(www.SoilandHealth.org)

1/14/2015

15

Root/Microbe Associations

Muruganandum, 2005

AMF on corn root with hyphae and spores. Green dye indicates glycoprotein production

• Increase plant nutrient uptake via mychorrhizal & bacteria associations

Rhizobia spp. nodules on legume root. 

Mycorrihizae Improve Phosphorus Uptake

• Fungi increase uptake of immobile ions including P and Zn. 

• Roots exudates stimulate hyphae growth and P uptake. Fungi receive carbohydrates. 

• Fungal hyphae also dissolve insoluble P by excreting H+ and organic acids. 

Mark Brundrett

Roots Are Amazing!

1/14/2015

16

Greenhouse Production

Advantages for using soilless media:

• No risk of soil-borne pathogens, nematodes and weeds

• No risk of residual pollutants or chemical fertilizers

• Custom-made media to create optimal root and microbial environment

Peat

Pine bark

Coir

Perlite

Vermiculite

Greenhouse Production

Field Production of Annuals

• Use allowable inputs

• Rotation strategy for pest management and nutrient use

• Crop diversification easy

• Stagger planting times for extended harvest

1/14/2015

17

Sources of Organic Seeds

• Seed Source Databases:– Organicseedfinder.com

• Seed retailers:– Johnny’s Selected Seeds

– Seeds of Change

– Peaceful Valley Farm Supply

– Southern States

– High Mowing Seeds

– Seed Savers Exchange

Jim Riddle

Growing Transplants Organically

• Sanitation: Bleach• Avoid synthetic wetting agents or starter fertilizer

• Recipe:–Mix 1 part each of peat, perlite, compost

–Add 1.5 c blood meal, bone meal, greensand, and superfine dolomitic lime

J. DeWitt, SARE

Field Production of Perennials

• Use organic perennial stock 

• If conventional stock exception is granted, then organic labeling is allowed only after the plant is managed organically for 12 months prior to sale or harvest

1/14/2015

18

GMOs, Hybrids, and Hierlooms

• GMOs = Genetically Modified Organisms

• Transgenic – a gene or genetic material that has been moved from one organism to another

• Corn (20 varieties) • Oilseed Rape/Canola (11 varieties) • Cotton (11 varieties) • Tomato (6 varieties) • Potato (4 varieties) • Soybean (3 varieties) • Sugar Beet (3 varieties) • Squash (2 varieties) • Cantaloupe • Rice • Flax • Raddicchio• Papaya • Alfalfa • Wheat 

GMO Crops

All are commercially available, but only the underlined commodities are commercially produced

GMOs, Hybrids, and Heirlooms

• Open Pollinated varieties are bred from parents that look similar to the offspring

• Hybrid (AKA F1) varieties are bred from crossing 2 parents that are different

• Open pollinated varieties will breed true, while hybrids will produce random results for many generations.

• Hierlooms are open pollinated varieties that have been around for 50+ years

1/14/2015

19

Selecting Cultivars

Seed Source Databases:

Organicseedfinder.com and

Seedalliance.org

Seed retailers:

• Johnny’s Selected Seeds

• Seeds of Change

• Peaceful Valley Farm Supply

• Southern States

• High Mowing Seeds

• Seed Saver’s Exchange

Crop Rotation

• Crop rotation is complex• Responsibilities include:

– ID rotation goals– ID resources/constraints– Gather and analyze data– Plan, execute rotation– Evaluate and adjust 

rotation

• 4‐5 year rotation common• http://www.sare.org/publ

ications/croprotation/croprotation.pdf 

What’s Trending in Organic

• Produce that is unique in shape, size or color

• Transplants

• Ornamentals produced using organic methods

• “Slow Flowers”

• Ingredients for processing: herbs, seeds used for oil production

• Pairing fresh produce with spice packets for quick-dinner options

• Ethnic vegetables

• KALE. The new superfood.

• 81% of parents buy organic products….(up from 73% in 2009), so anything you can market to kids is a plus!

1/14/2015

20

Certified Organic or Not?

• Can you define your motivations?

• Can you work outside of your comfort zone –small risks, but not necessarily big ones?

• Are you willing to dedicate sufficient time to see your system change?

• Will it improve your quality of life? – Improved financial health (does certification bring new market opportunities?)

– Build community (professional and personal)

– Conserve resources (so fewer inputs needed…)

First Steps

• Planning ahead is 75% of effort

• Sell before you plant

• Do your homework: 

– Be prepared to react quickly to serious pest threats, but allow your garden to harbor some pests

– Rely on soil tests to guide your fertility plan

• Record a baseline

• Be patient ‐ Organic systems are more than input substitution; they take time to develop

Sustainable Agriculture

“The hallmark of an alternative farming approach is not the conventional practices it rejects but the innovative practices it includes.”

‐National Research Council

Alternative Agriculture (1989)