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Similar a Southern sawg systems design for organic market farms
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Southern sawg systems design for organic market farms
- 1. This presentation of 76 slides took between 1 hr and 5 minutes to 1 hr and 15 minutes with a few questions asked during the presentation.
- 2. Systems Design For Organic Market Farms George Kuepper Kerr Center for Sustainable Agriculture
- 3. A Production System that… respond(s) to site-specific conditions by integrating cultural, biological and mechanical practices that foster cycling of resources, promote ecological balance, and conserve biodiversity. NOP Definition per §205.2
- 4. Fertilization Weed Control Insect Control Disease Control
- 5. HEALTHY SOCIETY HEALTHY PEOPLE HEALTHY FOOD HEALTHY SOIL
- 6. From Air & Water: Carbon (C), Hydrogen (H), Oxygen (O) Macronutrients: Nitrogen (N), Phosphorus (P), Potassium (K) Secondary Nutrients: Calcium (Ca), Magnesium (Mg), Sulfur (S) Micronutrients: Iron (Fe), Boron (B), Copper (Cu), Manganese (Mn), Zinc (Zn), Molybdenum (Mo), Chlorine (Cl) Also important to biological systems: Selenium (Se), Vanadium (V), Cobalt (Co), Silicon (Si), Iodine (I), Sodium (Na), others…
- 7. Organic Soil Management — An Old Saying among Organic Farmers
- 8. The Soil Food Web 2005 National Center for Appropriate Technology
- 9. What the Food Web Needs Sunlight Air Water Organic Nutrient Matter 2005 National Center for Appropriate Technology Elements
- 10. Organic Soil Management Feeding the Soil Food Web means providing organic matter as food. In organic farming, this has been called the Law of Return— returning mineral- rich rich organic material to the soil.
- 11. Plant Nutrition Under Natural Conditions Source of plant nutrition: Digestive - plant residues processes and - animal remains nutrient recycling - animal wastes in the Rhizosphere: The Soil Food Web Parent Soluble Minerals Plant Rock 11 Antibiotics, Chelates Other ―phytamins‖ Roots Material Glomalin, Bact. slime 2005 National Center for Appropriate Technology
- 12. Conventional Management Organic Matter Conventional ζ as Crop Soluble ζ Residues Fertilizers Digestive ζ processes and nutrient recycling in the Rhizosphere: The Soil Food Web Parent Rock 12 Soluble Minerals Plant Antibiotics, Chelates Material Other ―phytamins‖ 2005 National Center for Appropriate Technology Roots Glomalin, Bact. slime
- 13. Organic Management Organic Materials and Methods: Composts Crop Residues Green Manures Livestock Manures Natural Fertilizers Biological Inoculants Digestive Rotations w/ sod crops processes and nutrient recycling in the Rhizosphere: The Soil Food Web Parent Rock 13 Soluble Minerals Antibiotics, Chelates Plant Material Other ―phytamins‖ 2005 National Center for Appropriate Technology Roots Glomalin, Bact. slime
- 14. Self-Generated Fertility Weed Suppression •Fixes nitrogen •Less weed stimulation •Makes nutrients available •Weed seed predation •Water conservation •Easier cultivation •Air/water balance Suppresses Disease Pest Insects Reduced •Natural antibiotics •More predators & parasites •Nematode predation •Natural insect disease agents •Aeration/Drainage •Induced resistance in crops •Induced resistance in crops
- 16. One Reason Why Organic Crops Tend to Resist Pests Mycorrhizal “infection” is a beneficial symbiotic relationship where plants trade carbohydrates for help in absorbing water and nutrients. Aids in stress Root from sorghum with vesicles ("little sacs") of the mycorrhizal fungus called Gigaspora rosea. reduction. http://microbezoo.commtechlab.msu.edu/zoo/zdrm0194.html
- 17. Organic Farmers claim: Organic Crops Resist Pests Do organically- grown plants develop induced resistance to diseases and insect pests?
- 18. Organic Crops Resist Pests •Predisposition theory •Due to general stress reduction? •Due to phytochemical agents?
- 19. GK’s College Soil Texts Soil Fertility and Fertilizers. Tisdale & Nelson. 1966. One passing mention on p. 506. The Nature and Properties of Soils. Brady. 1974. Two- page discussion. Soils: An Introduction to Soils and Plant Growth. Donahue, Miller, & Shickluna. 1977. Three pages. The Soil and Health: A Study of Organic Agriculture. Albert Howard. 1947. Thirty pages.
- 21. The Most Common Approach… …to building biologically active soil is COMPOST; also the planned use of raw manures and other organic materials .
- 22. *A long-term planned crop rotation in which a significant percentage of the land is planted to season-long cover crops each year.
- 24. 1. Crop Rotation 2. The inclusion of cover crops within a crop rotation
- 25. Put simply, crop rotation is the sequencing of crops on a field over time.
- 26. A-1 2008 *Tomatoes* 2009 Okra 2010 Cowpeas 2011 Corn Example of a 2012 *Tomatoes* 4- crop rotation A-2 2008 Corn 2009 *Tomatoes* over 5 seasons 2010 Okra 2011 Cowpeas 2012 Corn A-3 2008 Cowpeas A-1 A-2 2009 Corn 2010 *Tomatoes* 2011 Okra 2012 Cowpeas A-4 2008 Okra 2009 Cowpeas A-3 2010 Corn A-4 2011 *Tomatoes* 2012 Okra
- 27. Cover crops are plants you grow or allow to grow, not for harvest, but for purposes such as preventing erosion, improving the soil, and weed control. Can be categorized by season— winter & summer.
- 28. A-1 2008 Tomatoes w/winter cover crop 2009 Okra “ “ “ “ Example of a 2010 Cowpeas “ “ “ “ 2011 Corn “ “ “ “ 4- crop rotation 2012 Tomatoes “ “ “ “ over 5 seasons, A-2 2008 Corn w/winter cover crop 2009 Tomatoes “ “ “ “ with winter 2010 Okra “ “ “ “ 2011 Cowpeas “ “ “ “ cover crops 2012 Corn “ “ “ “ A-3 2008 Cowpeas w/winter cover crop 2009 Corn “ “ “ “ A-1 A-2 2010 Tomatoes “ “ “ “ 2011 Okra “ “ “ “ 2012 Cowpeas “ “ “ “ A-4 2008 Okra w/winter cover crop 2009 Cowpeas “ “ “ “ 2010 Corn “ “ “ “ A-3 2011 Tomatoes “ “ “ “ A-4 2012 Okra “ “ “ “
- 29. Small Grains like rye, wheat, or triticale Annual winter legumes like vetch, crimson clover, arrowleaf clover, or Austrian winter peas Brassicas like turnips, mustards, rape, or tillage radish
- 30. Kerr Center’s A-1 2011: Early Vegetables w/ winter CC Cannon Rotation Plots 2012: Green Fallow “ “ “ Early Vegetables: those planted in 2013: Late Vegetables “ “ “ spring prior to July 1st 2014: Green Fallow “ “ “ •Tomatoes •Peppers A-2 •Okra 2011: Green Fallow w/ winter CC 2012: Early Vegetables “ “ “ •Sweet Potatoes 2013: Green Fallow “ “ “ 2014: Late vegetables “ “ “ A-3 2011: Late Vegetables w/ winter CC 2012: Green Fallow “ “ “ 2013: Early Vegetables “ “ “ 2014: Green Fallow “ “ “ A-4 2011: Green Fallow w/ winter CC 2012: Late Vegetables “ “ “ 2013: Green Fallow “ “ “ 2014: Early vegetables “ “ “
- 31. Kerr Center’s A-1 2011: Early Vegetables w/ winter CC Cannon Rotation Plots 2012: Green Fallow “ “ “ Late Vegetables: those planted in 2013: Late Vegetables “ “ “ summer or fall after July 1st 2014: Green Fallow “ “ “ •Summer squash •Winter squash A-2 •Pumpkins 2011: Green Fallow w/ winter CC 2012: Early Vegetables “ “ “ •Flour & meal corn 2013: Green Fallow “ “ “ 2014: Late vegetables “ “ “ A-3 2011: Late Vegetables w/ winter CC 2012: Green Fallow “ “ “ 2013: Early Vegetables “ “ “ 2014: Green Fallow “ “ “ A-4 2011: Green Fallow w/ winter CC 2012: Late Vegetables “ “ “ 2013: Green Fallow “ “ “ 2014: Early vegetables “ “ “
- 32. Kerr Center’s A-1 2011: Early Vegetables w/ winter CC Cannon Rotation Plots 2012: Green Fallow “ “ “ Green Fallow: growing summer cover 2013: Late Vegetables “ “ “ crops throughout the whole growing 2014: Green Fallow “ “ “ season A-2 Green fallow cover crops are typically 2011: Green Fallow w/ winter CC annual forage sorghums (e.g. sudan- 2012: Early Vegetables “ “ “ grass), millets, cowpeas, buckwheat, 2013: Green Fallow “ “ “ lab lab,—individually or in some 2014: Late vegetables “ “ “ combination A-3 2011: Late Vegetables w/ winter CC 2012: Green Fallow “ “ “ 2013: Early Vegetables “ “ “ 2014: Green Fallow “ “ “ A-4 2011: Green Fallow w/ winter CC 2012: Late Vegetables “ “ “ 2013: Green Fallow “ “ “ 2014: Early vegetables “ “ “
- 33. “Because we said so!” —NOP § 205.205 Crop rotation practice standard. The producer must implement a crop rotation including but not limited to sod, cover crops, green manure crops, and catch crops…
- 34. DISEASE CONTROL Clubroot, fusarium yellows, blackleg, & black rot in cole crops Black rot in pumpkins White rot in onions and garlic Root rots in beans & peas Gummy stem blight in cucurbits Early blight in solanaceous Photo: Gummy Stem Blight crops like tomatoes and potatoes
- 35. Brassicas: cabbages, Solanaceous: broccoli, cauliflower, tomatoes, potatoes, kale, brussels sprouts peppers, eggplant, Cucurbits: melons, tomatillo squashes, pumpkins, Umbels: carrots, dill, cucumbers, gourds fennel, parsley, celery, Legumes: English Composites: peas, southern peas, sunflower, lettuce, peanuts, beans, faba artichoke, jerusalem beans, soybeans artichoke Alliums: onions, garlic, Grasses: popcorn, chives sweetcorn, sorghum
- 36. Winter 2012 Cover Tomatoes Crop Winter 2013 cover Tomatoes Crop This is NOT what we mean by rotation!
- 37. WEED CONTROL Changes in timing and manner of seedbed prep, cultivation, & harvest “Cleaning crops”
- 38. November 1, 2007
- 39. Bermudagrass
- 40. Bermudagrass Strengths Perennial Summer season Drought tolerant Encouraged by mowing Many means for propagation and spreading Weaknesses Winter tillage Shade
- 41. Green Fallow in Rotation as a “Smother Crop” Sorghum- Sudangrass Seth Stallings Student Intern 2010
- 42. It has to grow during the same season as the target weed(s). A winter cover crop is not going to smother a summer weed. It must have a competitive advantage or advantages over the target weed(s), e.g. shade provided by height and canopy; earlier emergence; greater drought tolerance; etc. It must demonstrate those advantages for the entire growing season of the weed(s), or long enough, to do the job. For example, if it drops its leaves early, weeds will have a chance to emerge and reproduce before the end of the season.
- 43. Cover crops grown for the purpose of out-competing and controlling weeds. ← Crotalaria Pearl Millet→ ← Buckwheat Southern Peas→
- 44. 1. That you work to accomplish multiple objectives with each action. Disease suppression Weed control 2. That you recognize every action has multiple effects.
- 45. …and include cover crops: SOIL HEALTH & FERTILITY Green Fallow crops are “Green Manures” that contribute organic matter
- 47. That you work to accomplish multiple objectives with each action. Disease suppression Weed control Organic matter for the Soil Food Web
- 48. …and include cover crops: SOIL HEALTH & FERTILITY Legume cover crops fix nitrogen for themselves and subsequent crops
- 49. Kerr Center’s A-1 2008 Rye w/peas, clover or vetch Cannon Horticulture Plots 2009 Rye w/peas, clover or vetch 2010 Rye w/peas, clover or vetch 2011 Rye w/peas, clover or vetch 2012 Rye w/peas, clover or vetch Winter Season: A-2 2008 Rye w/peas, clover or vetch When we grow 2009 Rye w/peas, clover or vetch 2010 Rye w/peas, clover or vetch most of our 2011 Rye w/peas, clover or vetch 2012 Rye w/peas, clover or vetch nitrogen. A-3 2008 Rye w/peas, clover or vetch 2009 Rye w/peas, clover or vetch 2010 Rye w/peas, clover or vetch 2011 Rye w/peas, clover or vetch 2012 Rye w/peas, clover or vetch A-4 2008 Rye w/peas, clover or vetch 2009 Rye w/peas, clover or vetch 2010 Rye w/peas, clover or vetch 2011 Rye w/peas, clover or vetch
- 50. ANN. SORGHUM GREEN FALLOW COWPEAS AS GREEN FALLOW 1. A winter cover crop of 1. A winter cover crop of rye plus winter vetch is rye plus winter vetch is planted in fall planted in fall 2. Both rye and vetch 2. Both rye and vetch emerge in early-mid fall emerge in early-mid fall 3. By spring, vetch will 3. By spring, rye will dominate the cover crop dominate the cover crop stand, with very little rye stand, with modest in evidence evidence of vetch
- 51. Using legumes as summer cover crops. This works fine where weed control objectives have been reached. Examples: Cowpeas (Iron & Clay), Sesbania, Crotalaria. Interplanting legumes with annual sorghums. Examples: Lablab, Cowpeas. More legumes as vegetable crops. : English peas, southern peas, peanuts, snap beans, dried beans, lima beans, faba beans, edamame soybeans, etc.
- 52. That you work to accomplish multiple objectives with each action. Disease suppression Weed control Organic matter for the Soil Food Web Nitrogen fixation
- 53. Buckwheat and southern peas are exceptionally good for beneficial insect habitats. Beneficials include pollinators, predatory and parasitic insects, predatory mites and spiders.
- 54. That you work to accomplish multiple objectives with each action. Disease suppression Weed control Organic matter for the Soil Food Web Nitrogen fixation Beneficial habitat for pollination & pest mgt.
- 55. Generally works well to smother emerging annual weeds, conserves moisture, moderates soil temperatures, and adds organic matter & nutrients.
- 56. Creating in situ Mulch With a Sicklebar Mower
- 57. Heirloom & Grafted Tomato Trials, 2010
- 58. Crimper /Roller
- 59. Crimper/Roller: adapted to a BCS Tractor
- 60. Crimper/Roller: Cowpeas
- 61. Kerr Center’s A-1 Green Fallow Cannon Horticulture Plots Supplementary Mulch Transfers A-2 Early Vegetables Field Borders A-3 Green Fallow Advantages: Late Vegetables •Conserves nutrients A-4 •Reduces weed introductions •No herbicide contamination Field •Saves $$ Borders
- 62. That you work to accomplish multiple objectives with each action. Disease suppression Weed control Organic matter for the Soil Food Web Nitrogen fixation Beneficial habitat for pollination & pest mgt. Supplying mulch
- 63. Provides for soil fertility, especially nitrogen Suppresses many crop diseases Thwarts many insect pests Reduces weed pressure Creates a biologically healthy soil which in turn: Self-generates soil fertility Suppresses Disease Reduces insect pests Suppresses weeds
- 65. Learn from model systems; don’t assume you have to adopt them wholesale.
- 66. …trades land for: labor required for annual weed control much of the organic matter normally imported as manure, compost, other high- carbon amendments most or all of the nitrogen usually brought in as expensive organic fertilizer many of the purchased pest control products needed in more intensive systems
- 67. Kerr’s 4-Year Bio-extensive Rotation Winter cover crops of grain rye with winter annual Legumes—all plots. Typically a Early Green warm season Vegetables Fallow smother crop of sudangrass Green Late Fallow Vegetables
- 68. Alternate Bioextensive Designs Green Green Vegetables Vegetables Fallow Fallow Vegetables Vegetables Vegetables Green Vegetables Green Fallow Vegetables Fallow Vegetables Vegetables Vegetables Vegetables Green Vegetables Green Fallow Fallow
- 69. CONVENTIONAL ORGANIC Fertilization Weed Control Insect Pest Control Disease Control
- 70. Good Organic Crop Off-Farm Inputs F e r t i l i z e r s — Pe s t i c i d e s Compost, Manure Organic Cultural Practices A Sound Organic System Rotations—Cover Crops Biologically Healthy Soil
- 71. Organic growing requires a systems approach in which our “tools” are used to accomplish multiple objectives. Organic Systems center on building healthy soil. Sound strategies typically include effective crop rotation, cover crops, and/or compost. Most systems still benefit from off-farm inputs, but are not designed to rely on them.
- 72. Crop Rotation and Cover Cropping on the Organic Farm by Seth Kroeck. NOFA Organic Principles and Practices Handbook Series. 95 p. Gaining Ground by Canadian Organic Growers, Inc. 2005. COG, 323 Chapel St., Ottawa, ON KIN 7Z2. 311 p. Organic Crop Production Overview by G. Kuepper & L. Gegner. 2004. http://www.attra.ncat.org/attra-pub/organiccrop.html Crop Rotation on Organic Farms: A Planning Manual (NRAES-177) by C. L. Mohler & S. E. Johnson. 2009. NRAES/Cornell Cooperative Extension , Ithaca, NY. 156 p. Cover Crops on the Intensive Market Farm by John Hendrickson. 2003. CIAS, University of Wisconsin–Madison. 20 p.
- 73. This publication outlines the origins of organic agriculture. It highlights the concepts, ideas, and milestones that define it as a distinct and sustainable approach to farming that involves more than simply precluding synthetic pesticides and fertilizers. 23 pages. Copies can be downloaded free- of-charge at: http://www.kerrcenter.com/publi cations/organic-philosophy- report.pdf Print copies can be requested from: The Kerr Center for Sustainable Agriculture P.O. Box 588 Poteau, OK 74953 Tel: 918-647-9123
- 74. Copies can be downloaded free-of- charge at: http://www.kerrcenter.co m/publications/summer- cover-crops.pdf Print copies can be requested from: The Kerr Center for Sustainable Agriculture P.O. Box 588 Poteau, OK 74953 Tel: 918-647-9123
- 75. Anne & Eric Nordell, Beech Grove Farm, Trout Run, PA. Look for their column: The Bioextensive Market Garden In The Small Farmers Journal
- 76. the international agrarian quarterly Mailing address Physical address Phone numbers PO Box 1627 192 west Barclay Drive 800-876-2893 Sisters, Oregon Sisters, Oregon 541-549-2064 97759 97759 541-549-4403 fax agrarian@smallfarmersjournal.com www.smallfarmersjournal.com
- 77. Contact Information: George Kuepper Kerr Center P.O. Box 588 Poteau, OK 74953 Tel: 918-647-9123 Fax: 918-647-8712 gkuepper@kerrcenter.com www.kerrcenter.com
Notas del editor
- When I first got out of the University, I was fortunate to take the lowest paying job available with Washington University, in St Louis, which was conducting the first large-scale study of organic farming in the U.S. This was back in the 1970s, by the way, when we were still wearing animal skins and living in caves.One of the most valuable things I learned while studying these farms was that, based on my conventional agricultural training, things didn’t really add up. Organic farms were doing much better agronomically and economically than they should have been, and it was mystifying…like learning that 2 plus 2 equals 5.It was clear to me that you couldn’t find what made them successful by picking them apart, but by seeing how they were put together—what their SYSTEM was.
- Now you hear a lot of people describe organic production as “systems-based”, but almost no one explains what that means or how an organic system is put together. And there are reasons for this; we are long-accustomed to think about our natural world in a reductionist way. That’s as it is…What I ‘ve been trying to do in my feeble way, is to explain how I understand organic systems and how I see them put together. And do it in a way that folks can follow.
- In conventional management we are encouraged to find all our solutions.Organic is a different kettle of fish.
- The rejoinder from the conventional ag side is that it is also soil-based; that it emphasizes soil fertility. That is what commercial fertilizers are about…providing the necessary chemical nutrients for plant growth, especially the macronutrients, NPK.And this is something on which organic agriculture and conventional agriculture don’t disagree—that plants need these nutrients. They have to be supplied one way or another for good crops.The original argument between the organic and conventional approach to farming centered largely on this issue.
- But before we get to the how-to stuff, I want to impress upon you folks how important a really vibrant, healthy organic soil can be, and what benefits you reap when you achieve it. Some of this you’ve already seen in my poor little illustrations…. Bacillus thuringiensisNote: mention “Weeds and What They Tell”
- An illustration.
- Now I can’t tell you all the reasons behind why organic crops are more resistant, but here’s one… mycorrhizal fungi. How many of you have read or heard about mycorrhizae?Mycorrhizae are fungi that live symbiotically with plant roots. Plants exude sugars from their roots to feed the fungi, and in turn the fungi help the plants absorb water and nutrients from the soil. Part of this is done simply by increasing the surface of the roots…I would be remiss if I did not tell you that predisposition theory appears to hold up well with pests from the crops native environment. It weakens when we deal with imported pests.
- On the previous slide, I listed something called “induced resistance” twice. You may not know this but traditional organic growers claim that crops grown organically naturally resist pests and diseases. That plants are NOT inherently susceptible to pests, AND that many, if not most pest problems are do some failure in how we manage or fail to manage our crops. This belief goes way back. Albert Howard talks about this in his 1947 book The Soil and Health—claiming he observed it frequently in his work. For what it’s worth, I’ve encountered it on what you might call matured organic farms—where organic practices have been in place for a few years and the farmers are good farmers by any standard. These farms typically have very few pest problems and require very few inputs to control them.
- Until recently I’d considered this essentially a notion residing in the organic literature, but there appears to be quite a bit of independent research and thought on the topic. This notion has been referred to as Predisposition theory. The science here goes back to the late 1800s. It basically says that when plants have proper nutrition, adequate air and water, and growing conditions, that they have a natural ability to resist most of the pests and diseases in their native environments. Put another way, if plants are fortified well and not stressed, they are not disposed to becoming sick or attacked by insect pests.Kinda like you and me. When we’re eating well, drinking enough water, getting the rest we need, we are a lot less likely to get sick. And those of you who have livestock…did you ever notice which animals are most loaded down with flies in summer? It’s the ones that are weak and already sick.In fact, traditional organic growers often call insect pests natures sanitation engineers, because they are clearing out the plants that aren’t up to snuff. They’re the wolves that take out the slow buffalo!!So when we see a pest or disease problem in organic growing, our first thought should be, “what am I not getting right?” “What might I fix that will prevent this problem?” What this truly means for us in organic growing is that we try to create an environment in which the stress on the plants in minimized. And a biologically healthy soil is one of the major things we try to provide to reduce this stress. It is not the only thing, but it is the first thing.
- There is a big focus on this these days in soil biology…People talk about it like it’s new science, but it ain’t. (Discuss slide)There is a real reluctance to give the organic pioneers credit for having pointed the way.
- Soooo. Now it is time to start talking about what we gotta do. First of all, you have to understand that this is a bit like the great philosophical conundrum: “What came first, the chicken or the egg?”Biologically healthy soil is both the cornerstone of a sound organic system AND it is also the result of a sound organic system. The fact is, they evolve, emerge, and mature together. The sooner you start, the sooner you will see the benefits emerge.
- That is what characterizes a bioextensive rotation; it has a significant percentage of land rested each year in cover crops. By significant, I mean from 25%-50%. That may seem a bit crazy to some of you, but wait till you get the full story.
- To illustrate how things can be put together, we’re going to rely on our own certified organic demonstration, that you will see later today. We created this demonstration primarily to show traditional organic practices centered on soil building.
- Now, I’m going to talk about our organic system. It is called a bio-extensive system, by the way. And it is one of the most sustainable and self-sufficientvegetable growing systems, and you’ll learn why as we go along. Our system begins with two main system elements: First, crop rotation, which is the sequence of crops you plant on a particular piece of ground over time. Crop rotation is essential to any good organic vegetable system. ANY good organic system. In fact it is required if you are going to be certified.And second, the planned, strategic inclusion or cover crops within the rotation scheme.
- Let’s come to terms on these two things: rotations and cover crops….Rotation, as you might assume, refers to the sequencing of different crops over time.Good Rotation, Poor Rotation, Non-Rotation.
- To give you an illustration of rotation: this is crops can be rotated over 4 fields. Focus on tomatoes…
- Cover crops, I mentioned, are the second key element in our system at Kerr Center. Cover crops are crops plants you grow or allow to grow, not for harvest, but for purposes such as preventing erosion, improving the soil, and weed control.We generally talk about two types: Winter and summer.
- Here is how winter cover crops might be introduced into the example rotation you’ve already seen…
- These are common options for cover crops in our part of the world.These combinations are what I use at the Kerr Center.
- This is what we actually do. Note that I group my vegetable crops into early and late… (Read Slide)
- (Read Slide)Note that I’m growing most of my cucurbits in this group. The reason is squash bugs.
- Explain Green Fallow…
- It begins with crop rotation.Why rotate crops?
- We’ll return for that to our rotation. The most basic reason that vegetable growers rotate is disease and insect pest control. If you do not rotate vegetables, problems can build up.
- You probably noticed that we’ve been talking about rotating vegetables by family, not by individual vegetables. This is how it is commonly done, because most pest and diseases are shared or hosted among members of the same family.
- And I want to make this point: growing a vegetable crop like tomatoes, following with a winter cover crop, and then growing tomatoes again is NOT a rotation.When we talk about crop rotation we are talking first and foremost about what you are growing during your usual production season.
- Another reason we rotate crops and plan those rotations carefully is to help us control weeds. In most of the surveys conducted with organic crop producers, they cite weed management as their single greatest challenge. Well, crop rotation also has an effect on weeds, in very real, very pragmatic ways. The most obvious is that, as you change crops year to year, the times when you break ground, cultivate, or mow changes; the kinds of cultivating and mulching change. These changes eliminate many of the niches that weeds exploit.There is also a concept we call cleaning crops. These are crops that are especially competitive with weeds and are easy to cultivate—like squash, okra, and Irish potatoes. It is a good idea in a crop rotation to have crops that are poor weed competitors, like onions or carrots, follow a cleaning crop the year before, because the weed pressure that year should naturally be less.Finally, some crops and cover crops are just naturally better weed competitors. That is what we exploit in our bioextensive rotation.
- To illustrate: When we broke ground on the Cannon Horticulture Site, it was a bermudagrass pasture.
- Anyone who grows vegetables in the South organically, you don’t feel too kindly towards bermudagrass. I often tell people it is considered the anti-Christ by organic growers.
- We can talk all day about what makes Bermuda so aggressive and such a problem. However, it also has some weaknesses. We zeroed in on it’s vulnerability to shade. So we designed our rotation and our selection of cover crops to control bermudagrass by shading it out.
- What we believed met all our criteria, however, were the annual sorghums—sudangrass or sorghum-sudangrass hybrids. Bermudagrass does not grow under a stand like this. Annual sorghums are also drought tolerant and they regenerate after mowing. So we can cut or graze around mid July, and get about the same amount of re-growth, again, for the fall. You will not get that from most of the other smother do not work quite this well.I can tell you now, with confidence, that there will be no active bermudagrass growing in that field the next year. This was 2010…I can tell you confidence because there was none in 2011!! Actually…there were very few weeds at all. Smother crops like this suppress a wide spectrum of weeds.Remember, an objective of an organic system is the to accomplish several things at the same time.
- These are just a few of the cover crops we looked at and continue to look at. For effectiveness and for the cost of seed, the annual sorghums do the best job for us…but stay tuned.
- Remember, this is about systems and systems thinking.
- But while weed management is one of the main reasons we use summer cover crops, there are other very compelling reasons. Another extremely important one is soil fertility and health. These covercrops, when they are mowed for mulch or tilled into the soil, provide an enormous amount of organic matter to the soil. And what is the primary food that makes the soil food web happy? Organic matter!!
- Better yet, look at the amount of organic matter growing here. Again, this is sorghum sudan. This is at a research station further south in Oklahoma—the only one with certified organic acreage. They’d applied a lot of poultry litter to this ground—something we don’t do. And it is possible that we are not getting the yields we might.
- But while weed management is one of the main reasons we use summer cover crops, there are other very compelling reasons. Another extremely important one is soil fertility and health. These covercrops, when they are mowed for mulch or tilled into the soil, provide an enormous amount of organic matter to the soil. And what is the primary food that makes the soil food web happy? Organic matter!!
- Our main strategy has been to grow most of our nitrogen during the winter months. That’s why the legumes. We want to avoid an over abundance of soil nitrogen, because this affects crop quality and it invites insect pests like aphids. Fortunately, when you grow legumes for nitrogen, your system is somewhat self-regulating. If there is an abundance of nitrogen in the soil, rhizobium bacteria get lazy and they don’t bother to fix any more.
- Nitrogen fixation is a bit self-regulating.
- As a result of these observations I believe I could benefit from a bit more nitrogen. Using legumes as summer cover crops. This works fine where weed control objectives have been reached. Examples: Cowpeas (Iron & Clay), Sesbania, Crotalaria.Interplanting legumes with annual sorghums. Examples: Lablab, Cowpeas.More legumes as vegetable crops. : English peas, southern peas, peanuts, snap beans, dried beans, lima beans, faba beans, edamame soybeans, etc.
- Now legumes and a number of other summer cover crops have one more important function I want to point out. They all are very valuable as beneficial insect habitat.
- What are the benefits of organic mulches?...
- One approach we’re using with organic mulches is sometimes called organic no-till. It entails growing a cover crop, killing it mechanically, and leaving it in place as a mulch. Here we’re mow-killing a winter cover crop for this purpose.
- And we’ve used that to grow tomatoes. This is an heirloom tomato trial—using this basic method, since 2009. It works well for us.
- Mowing isn’t the only mechanical killing strategy. Some of you may know about the roller crimper. Rodale institute is doing a lot of work with that on row crops. I think Kathleen Delate iniowa is also doing some work.
- Here it is mounted. The logic behind this creature is that it presses the cover crop down and breaks the stems every few inches. If the plants are large and mature enough, it provides a final kill and you can plant or transplant directly into the residue with no-till capable equipment.
- We tried this shortly after we got it on cowpeas. Thought we might plant pumpkins here also. But we didn’t get a good kill and the pumpkins never had a chance as the cowpeas recovered real quick.
- However, we often need additional mulch, and we harvest that from our plots—either winter cover crops or green fallow. We’re moving nutrients and organic matter around, sure. But with our rotation that all averages out over time.Growing and using your own mulch protects against the introduction of new weeds and the damage from herbicide-contaminated materials. Clopyralid class of herbicides.
- How long have I been talking this morning? Too long, I suppose. But I’ve been talking about putting together an organic system, and I’ve really only talked about two techniques, right? Rotations and cover crops?But let’s take stock on that. In the system where I’ve put these two techniques to work, what am I accomplishing?....This is a heckuva lot to be accomplished here. Remember I said that having such a large percentage of ground in cover crops during the growing season seems crazy. Well, it is really a trade-off. You are trading land for:The labor you’d otherwise pay for in weedingFor the additional pest control products you might have to buyFor the additional fertilizer and organic soil conditioners you’d need to find or buyThis, by the way, is how organic growers—the experienced ones—think. They look at trade-offs and the possibilities of accomplishing things biologically, rather than getting their solutions out of a bag or bottle. They realize that they can make a single tool do many things for them. They also realize that anything they do, will have many effects, some positive, some negative. This is a wholistic approach to growing crops
- Before we move on I wanted to say one more thing about bioextensive systems. I don’t want you thinking that 50% is a rigid guideline limiting your rotations.
- I’m sure you’re getting the idea, huh? In this case only 1/4th of the land is in green fallow. Obviously I’m a big believer in resting the land and building the soil using green fallow. I’m not the only one. Verne Grubinger, a vegetable crop specialist from the Northeast recommends this as a minimum.
- Now, both the bioextensive and the biointensive models share two things:They emphasize the vital importance of a biologically-healthy soilThey work with systems design which is near the base of the zuggurat pyramid, here. In other words they reinforce the foundation of your overall organic production system. When you invest in building your foundation, it is like adding to the principle in a bank account. If you had to you could live off the interest for awhile, if times get bad.There is another approach of course, which I discourage you from following, unless you have an abundance of money to throw at your farm. That’s the input substitution approach. It actually arises from the conventional approach to farming where your growing system is built around all the stuff in bags and bottles. The only difference here is that the bags and bottles contain friendlier materials.Purchased organic inputs are fine!! I’m not trashing them. Just don’t build your system around them. If you neglect the foundational practices, your whole system structure will become weak, wobbly and less sustainable.
- Here are a few resources on crop rotation. They are good on principles, but don’t reflect conditions in the South and Mid-south very well.
- A lot of what I’m going to talk about is in this little reading assignment I sent you all. You DID read it, didn’t you??
- Again, if you did your homework, your read this little publication, which tells you something of what we’re trying to accomplish out here. Also, we have reports on all the heirloom vegetable trials we’ve done. Those are on our Web site, too.
- As for the bioextensive approach. We’re not the only one’s that are pursuing it. There is one very well-known organic operation in Pennsylvania you would know about if you read the Small Farmer’s Journal. It’s Beech Grove Farm, operated by Anne and Eric Nordell. Yes, they farm with horses, but no, they’re not Amish or Mennonite. Sustainability is just very important to them and they’ve been doing this commercially since some time in the 1980s, I believe.
- The Small Farmer’s Journal is a very good resource. Here’s their contact information.We will be pulling together contact information on some other excellent periodicals you should know about. We’ll have that for you in our next session here in May.