MANAGING WEEDS AS COVER CROPS

The trick to biological farming is knowing how to manage weeds.  “Manage” does NOT mean “kill”.

Internet trolls are bombarding my e-mail box with comments like:  “You can’t plant crops in weeds!  That’s why they invented tractors”.  Horse power is irrelevant and yes, you can plant crops in weeds:  I manage 90,000 acres without herbicides or mechanical cultivation.  Here is how I do it:

(1)  Manage Weeds as Cover Crops.  Think of weeds as a multi-species cover crop that costs nothing to seed.  This will save you about $40 per acre, right off the bat.  $40 x 90,000 acres = $3,600,000.  We are not talking tree-hugging here.  This is serious agronomy.

Grow weeds to protect your top soil.  A typical corn-soybean farmer in Iowa loses 2 1/2% of his land yearly = 20 tons of earth per acre = $450 per acre at $22.50 per ton (U.S. average top soil price, delivered).  Weeds have value.

If you don’t have enough weeds for a winter cover crop, seed 3 to 4 bushels of oats per acre.  Oat roots prevent soil erosion over winter.  Oats winterkill so no herbicides are needed.  Surface trash is minimal and will not interfere with conventional planting equipment.

(2)  RULE:  Keep Fields Green.  Photosynthesis is the process where plants use water, air and sunlight to make sugar.  More photosynthesis = more sugar = more plant growth = higher yields.  Bare fields are not profitable.  Smart farmers keep their soil covered with growing plants year-round.  Plant cash crops whenever possible.  Sow cover crops for mulch or fertilizer.  Seed weeds when there is no time or money to grow anything else.  The goal of biological farming is to produce the most possible organic matter per square foot.  Grow anything rather than leave soil bare.

The underlying principle of biological weed control is plant competition.  Keep the ground covered with growing crops year-round and weeds do not have a chance to get established.  Never leave the soil bare, not even for a single day.

For example:  Plant winter wheat into standing Dutch White Clover (Trifolium repens) using no-till equipment.  Next summer, harvest wheat then immediately (the same day) plant turnips into wheat stubble and clover living mulch.  Field stays green year-round.  Weeds cannot grow because they are constantly shaded by competing plants.

(3)  Sow Weed Seeds.  If you have tired, sick or dead ground, or no top soil, go to your nearest grain elevator and fill your truck with weed seeds.  These are usually free.  Some elevators charge a nominal fee for “elevator screenings” which contain many weed seeds.  Sow liberally, at least 40 pounds per acre.  Prepare for amazement.  Weeds are Nature’s Band-Aid, a fast growing cover crop evolved specifically to heal bare earth.  On steep slopes or mine reclamation sites, spread straw or spoiled hay mulch to protect germinating weeds.

(4)  Fertilize and Water Your Weeds.  Every time I say this, half my audience leaves the room.  No, I am not crazy.  Yes, I do know what I am talking about.  I farm without any government subsidies and each acre earns substantial profit.  It pays to feed and irrigate weeds (if possible).  Remember:  Weeds are a cover crop.  You want every field blanketed with a luxuriant jungle of weeds at least 6 feet high.  So water and fertilize as needed, and do not worry about what your neighbors say.  Farming is not about yields; farming is about the bottom line.  Weeds put money in your pocket.

(5)  Feed the Weeds and the Weeds will Feed Your Crops.  Weeds have enormous root systems in proportion to their stems and leaves.  Many weeds also have tap roots that plunge deep into the subsoil.  Translation:  Weeds are great at scavenging nutrients that would otherwise leach away.  Weeds have quick growth response to plant food so a little fertilizer goes a long way.  A few pounds of nitrogen create a vast jungle of vegetation that makes good mulch and fertilizer.  The average weed contains twice the nutrients of an equal weight of cow manure.  Broad leaf weeds rot quickly so fertilizer elements are rapidly recycled for crop use.  Plant crops and weeds together and yields often increase.  The reason is ecologic synergy = plant symbiosis.  Weeds both compete AND cooperate with neighboring plants.  Water and nutrients are shared so crops and weeds grow better.  I learned this lesson farming melons.  The best fruits came from the weediest fields.  So I started planting melons into weeds.  The weeds provided light shade and the melons followed weed roots down into moist subsoil.  Come drought and clean cultivated fields produced little or no crop.  Melons and weeds yielded fair crops.  Irrigated melons and weeds overfilled my trucks with fruit.  Think about this the next time you buy a drum of herbicide.

(6)  Use Weed Seed Meal Fertilizer.  How would you like to slash fertilizer costs?  Get weed seeds or screenings from your local elevator.  Grind them with a hammer mill or roller mill.  Broadcast 4 tons per acre or drop 10 pounds per 25 feet of row.  Unlike chemical fertilizers weed seed meal will not burn crop roots so you can hurl nutrients with wild abandon.  If you do not have any weed seeds, use any other waste seed like spoiled corn, brewer’s grain, or broken soy beans.

To use LIVE weed seeds as fertilizer broadcast seeds into a standing cover crop like Red Clover (Trifolium pratense).  Earthworms, ants, beetles and other critters eat the weed seeds.  Clover kills any weeds that germinate.  Caution:  Don’t try this unless you have a tall, aggressive cover crop that blankets the soil with dense shade.

(7)  RULE:  Apply Chemical Fertilizer Only to Growing Plants.  This rule covers all crops (including weeds) without exception.  It makes no sense to spread fertilizer on bare ground.  Chemical nutrients are wasted unless there are live roots waiting to absorb them.  For best results, synthetic fertilizers should be applied in small doses throughout the growing season, ideally diluted in irrigation water.  Feed growing crops only and well water stays pure = free of nitrates.

(8)  Good Farmers Grow Fungi.  The Fungi Grow the Crops.  Think of all the pipes, wires and roads needed to run a modern city.  Without these conduits life would be nearly impossible.  A corn field is no different.  Under the soil surface is a jungle of lifeforms, a whole zoo full of critters exceeding the combined population of the world’s largest cities.  And every one of these underground citizens depends on fungi for survival.  Millions of miles of microscopic fungi tie the underground world together.  Fungi are the interstate highway system of the soil ecology.  Water and nutrients are conveyed to hungry roots.  Plants share resources through fungal networks.  Many crops are so dependent on fungi that they cannot exist without these symbiotic micro-organisms.  Kill the fungi and the soil ecology collapses.  Yields plummet and fields become sick and barren.  Try to farm dead soil and you will spend vast sums for synthetic fertilizers, pesticides, and irrigation.  Today, this is called “conventional agriculture” and most growers lose money on every acre they plant.  There is a better way to farm.

Fungi like cool temperatures, a moist environment, plenty of air, and lots of organic matter.  Rip up the ground with plows and the fungal network is destroyed.  Soil temperatures spike, the earth is parched, a cyclone of oxygen rushes into the ground, and organic matter burns away in a firestorm of excess decomposition.  The result is like dropping a nuclear bomb:  Billions of critters die and the soil ecology is devastated.  Recovery takes years.

Sell your plows, disks and harrows — you don’t need them.  Grow weeds or other cover crops and leave the fungi alone.  Open the soil just enough to get seeds or transplants into the ground.  Further disturbance cuts profits and yields.

(9)  Till Your Fields with Earthworms.  My Grandfather taught me:  “Feed the worms and the worms will tend your crops”.  Common earthworms (Lumbricus terrestris) eat organic matter and excrete enough manure to grow 200 bushel corn = 11,200 pounds per acre.  They also burrow 6 feet into the subsoil.  My fields average 1 million worms per acre.  That’s about 23 worms per cubic foot = 1,200 miles of burrows per acre.  When thunderstorms drop 2 inches of rain per hour my neighbors’ fields wash away.  My soil stays in place.  When drought bakes the county, my corn yields over 100 bushels per acre (without fertilizer, herbicides, cultivation or irrigation).  How is this possible?  Plant clover and earthworm populations double.  I seed clover into weeds and the worms feast on the multi-species “salad bar”.  Mind you, this process does not occur overnight.  It took 12 to 15 years to wean my fields off synthetic nutrients.  That’s 4 to 5 generations of earthworms.  I used to borrow mountains of cash to buy farm chemicals.  Now I plant clover and have no debts.

(10)  Grow Your Own Fertilizer:  Conventional green manures are plowed into the soil.  A less invasive technology is called Chop-And-Drop.  Use a rotary mower, flail mower, bush hog, forage chopper, or common lawn mower to cut plants into small pieces that decompose quickly for rapid nutrient cycling.  Immediately sow or transplant another crop before weeds start germinating.  Alternatively, knock down cover crop with a roller-crimper or sickle-bar mower then plant through the mulch using no-till equipment.  For example, I sow Hairy Vetch = Winter Vetch = Vicia villosa in October then roller-crimp vines in May.  Vetch controls weeds and fixes sufficient nitrogen for 200 bushel corn or any other crop I want to grow.  Remember:  Chop plants into small pieces for fast-acting fertilizer.  Crimp or cut whole plants for mulch.  Finely chopped plants will NOT control weeds.

(11)  Use Mulch-In-Place.   Think of how much money you will save if you don’t have to buy herbicides or cultivate fields multiple times.  The savings in diesel fuel alone will pay for a 2-week vacation anywhere you care to go.  Let your neighbors plant seed in cold ground.  Be patient and give your weeds more time to grow.  Wait until the soil warms and weeds are at least 5 feet high.  Kill weed cover crop with a roller-crimper or sickle-bar mower then immediately seed or transplant through weed mulch with no-till equipment.  Mulch retards weed growth 4 to 6 weeks — just enough time for your crop to germinate and start covering the rows.  Once the crop canopy closes weeds are shaded and there is no more work until harvest.

There are many variations of Mulch-In-Place.  For example, use a forage chopper to deposit weed mulch into convenient windrows then transplant pumpkins or other fast-growing vine crops through the mulch.  Alternatively, mow strips through weed covered fields.  Transplant vine crops down mowed rows then roll out drip irrigation tape.  Use mowed weeds to mulch crops until plants are established.  Once vines begin to run they overwhelm weeds between rows.  Standing weeds protect vine crops from insect pests.

If you do not have weedy fields, sow winter rye = cereal rye = Secale cereale at 3 bushels per acre.  Roller crimp or sickle-bar mow when rye reaches 5 to 6 feet high or when grain reaches soft dough stage.  Immediately seed or transplant through rye mulch using no-till equipment.  Note:  Mulch-In-Place works with just about any cover crop that grows at least 5 feet high and produces 4 to 5 tons of mulch per acre.

Who needs Monsanto?  Grow mulch crops and never buy herbicide again.  Sell your spray rig and pay off farm debts.

(12)  Use Weeds to Control Insect Pests.  Plant weeds with your crops and you will never have to buy insecticides again.   Set 4 rows of tomatoes then leave a strip of weeds.  Seed 4 rows of sweet corn and leave another strip of weeds.  Plant 4 rows of sweet potatoes with a third strip of weeds.  Drill 4 rows of sunflowers and a fourth strip of weeds.   Alternate crops and weeds across fields and farms, following land contours.  Adjust strip widths to match planting and harvesting equipment.  Weeds provide food, shelter and alternate hosts for beneficial insects.  The good bugs eat the bad bugs.  Native weeds should cover at least 5% to 10% of every farm, even if you also grow insectary plants.  I learned this lesson the hard way.  I grew dozens of crops with small flowers especially to feed predatory and parasitic insects.  Biological control was only partly successful until I planted native weeds next to crops needing protection.  Close proximity is essential as many beneficial insects penetrate only 200 feet into a field over the course of a growing season.  Remember:  You need a mix of native weeds AND insectary plants to protect cash crops.  Maintain biological diversity and pests rarely cause economic damage.  I have not purchased insecticides (organic or synthetic) in 18 years.

(13)  Plant into Standing Weeds (Sow-And-Go).  This works best with fall planted winter grains like wheat, barley, and rye.  Seed directly into standing vegetation using no-till equipment.  (Standing weeds trap winter snow).  If desired, you can seed Dutch White Clover (Trifolium repens) at 8 to 12 pounds per acre with winter cereals.  The clover provides 90% to 95% weed control, about as good as glyphosate (Roundup).  Expect 60% to 70% of conventional yields without fertilizer or irrigation.  In a dry year you might lose your crop.

If you do not have no-till equipment, try surface seeding = Sow-And-Mow.  This works best with pelleted seed.  Broadcast seed into standing weeds then immediately roller-crimp or cut vegetation with a sickle-bar mower to cover and protect germinating grain.  Come back next summer and harvest your crop.

Alternatively, broadcast winter grain into standing weeds then mow with a rotary mower or flail mower to chop vegetation into small pieces.  Immediately till field with a rear-tine rototiller set to skim soil surface at 2 inches depth.  Make only 1 pass across field.  Your field will look ugly but will make a good crop = 40 bushels (2,400 pounds) of wheat per acre in cool, temperate climates with 40 or more inches of rainfall yearly.

If you have no farm machinery, try the ancient Roman practice of Stomp Seeding.  Fence field securely.  Broadcast seed into standing vegetation.  Turn in livestock (cattle, sheep or goats) until they eat about 1/2 of the vegetation and stomp the other half into mulch.  Livestock must be well crowded in order to make this work.  Allow each animal only enough space to turn around = use very high stocking densities = mob grazing.  For example, 600 to 1,200 cows per acre.  Directly forage is exhausted, move livestock to a new enclosure or fresh pasture.  If field is “tired”, “sick” or barren, feed livestock in their enclosure until they deposit 1/2 to 1 pound of manure per square foot = about 11 to 22 tons per acre, then move animals to another enclosure.

(14)  Plant into Living Mulches.  This is ideal for transplants or crops with large seeds.  For best results use no-till equipment and low-growing legumes like Dutch White Clover (Trifolium repens) or Crimson Clover (Trifolium incarnatum).  Seed Dutch White Clover at 8 to 12 pounds per acre, or Crimson Clover at 14 pounds per acre.  Seed or transplant directly cover crop reaches mature height of 6 inches for Dutch clover or 12 inches for Crimson clover.  It is good practice to mow clover before planting to give crops a head start.  Watch field carefully.  When the FIRST seedling emerges, immediately mow field as close to soil surface as possible.  If clover is especially vigorous, it may be necessary to mow again 2 weeks later.  Note:  If desired, you can grow corn (Zea mays) with tall-growing Red Clover (Trifolium pratense) using the same method.  No fertilizer, herbicides or cultivation are necessary if clover grows a full year before planting maize.

Planting into clover is a good way for farmers to learn how to work with weeds.  Clover is convenient to grow because its height is easily controlled.  Alternatively, you can make your own cover crop mix and use this as a substitute for naturally weedy fields.  Combine 2 cool season grasses + 2 cool season legumes + 2 cool season broad leaf plants + 2 warm season grasses + 2 warm season legumes + 2 warm season broad leaf plants + 2 root crops (tillage radish, stock beets, or turnips) = 14 species cover crop mix.  Plant at least 20 pounds per acre.  If desired, more species can be added.  For best economy, select cheap seed to keep costs below $40 per acre.

Remember:  All living mulches compete with their companion crops for water, light and nutrients.  For example, Dutch White Clover grows only 6 inches high but this is enough to shade the lower stems of wheat.  Plant Dutch clover with tall wheat varieties and yields are normal.  Seed Dutch clover with semi-dwarf or dwarf wheat and yields may drop 30% to 50%.  Use common sense when pairing cash crops with clover, weeds, or any other living mulch.  Combine tall varieties with low-growing cover crops.  Water and fertilize for both cash crop AND cover crop.  If necessary, retard or kill companion crop by mowing, mulching or roller-crimping.

(15)  Grow Crops and Animals Together.  2,000 years ago the Romans discovered that manure is more profitable than meat.  It pays to keep animals just for their manure.  Pastures grow better when grazed.  Crops grow better when dunged.  There is a significant difference in growth between plants fed manure or artificial nutrients.  No one has yet figured out why.  Drive a herd of cattle into high weeds (or a mixed species cover crop).  Let the cows graze until they have eaten 1/2 of the forage and stomped the rest.  Move herd to fresh pasture then immediately sow small grains or other crops with no-till equipment.  No herbicides, cultivation or chemical fertilizers required.

The cheapest way to keep livestock is to graze them on fresh, green grass.  Move herds to new pasture at least once daily and do not re-graze paddocks until forage has recovered.  This is called rotational grazing and eliminates the costs of building barns, making hay, and spreading manure.  If you don’t have tidy pastures seed mixed-species cover crops or graze native weeds.  What the cows don’t eat the goats will, and what the goats don’t like the sheep will relish.   Range chickens 3 or 4 days behind cows and the birds eat the fly maggots.  Nothing goes to waste and meadows stay clean and sanitary.

Not all weeds are good to have around.  When weeds get out of control there are 2 easy ways to recover ecologic balance:  (1)  Grow cover crops in series, or  (2)  Graze with mixed livestock.  Cover crops overwhelm weeds by shade and competition.  Mixed livestock eats everything in sight.  Either way, problem weeds are eliminated and crop rotation can proceed normally.

(15)  Think Unconventionally.  If everyone around you grows corn, plant something else.  If everyone says you have to spray, don’t.  Conventional wisdom is often just plain wrong.  Do not be afraid to experiment.  Every year I reserve about 2% of my land for agricultural research.  I learned to farm by doing the opposite of what the “Experts” advised.  Along the way I have enjoyed amazing success and spectacular failure.  Both are equally instructive.  Monsanto says weeds are bad and should be eradicated.  I think differently.  For example, in my garden (a jungle of weeds), I thin Bull Thistles (Cirsium vulgare) until they stand about 1 foot apart, then I plant 1 pole bean seed per thistle plant.  The beans climb the thistles and I do not have to cut poles.  My spray-by-the-calendar neighbors told me to cut the weeds or mulch them into oblivion.  Instead, I conducted a paired comparison of 100 beans on thistles with 100 beans on poles.  Thistles beat poles by a slight margin, 3.55% over a 5-year trial.  This is only one of many examples of symbiosis between weeds and crops.  Widely spaced weeds often increase crop yields.  I don’t recommend planting beans and thistles on a commercial scale, but neither do I insist on weed-free fields.  Weeds spaced 3 feet apart (about 5,000 weeds per acre) no longer bother me.  The tomatoes don’t seem to mind and I don’t have to spray for hornworms.  Learn from nature or buy from Monsanto.

Related Publications:  Weed Seed Meal Fertilizer; Trash Farming; No-Till Hungarian Stock Squash; Planting Maize with Living Mulches; Living Mulches for Weed Control; Pelleted Seed Primer; Crops Among the Weeds; Forage Maize for Soil Improvement; and Rototiller Primer.

Would You Like To Know More?  Please visit:  http://www.worldagriculturesolutions.com  — or —  send your questions to:  Eric Koperek, World Agriculture Solutions, 413 Cedar Drive, Moon Township, Pennsylvania, 15108 United States of America  — or —  send an e-mail to:  worldagriculturesolutions@gmail.com

About the Author:  Mr. Koperek is a plant breeder who farms in Pennsylvania during summer and Florida over winter.  (Growing 2 generations yearly speeds development of new crop varieties).

 

 

 

 

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2012 ORGANIC CABBAGE TRIAL

This is a demonstration project:  A single field without controls or replications for statistical analysis.  The purpose of this trial is to explore possibilities before launching a full-scale research program.

Experimental Location:  Homestead, Florida, United States of America.  25.47 degrees North Latitude, 80.52 degrees West Longitude.

Climate:  Homestead has a semi-tropical monsoon climate with a hot, humid summer and a cooler, drier winter.  Average annual temperature = 74.8 degrees Fahrenheit = 23.75 degrees Centigrade.  Average annual rainfall = 58.23 inches = 147.90 centimeters.  Average January low temperature = 56 degrees Fahrenheit = 13.2 degrees Centigrade.  Average January high temperature = 77 degrees Fahrenheit = 24.8 degrees Centigrade.  Frost Free Growing Season = approximately 355 days.  Homestead gets about 5 to 10 frosts (36 degrees Fahrenheit) and freezes (32 degrees Fahrenheit) each winter.

Experimental Plot Size:  1 acre = 208 feet x 208 feet (approximately).

Soil Type:  Everglades Peat = Muck

Crop Rotation:  Sunn Hemp (Crotalaria juncea) was planted in spring 2012 to suppress weeds and control root knot nematodes.  Hemp cover crop was shredded with a forage chopper then Crimson Clover (Trifolium incarnatum) was broadcast seeded over hemp mulched field.  Cabbage seedlings were transplanted into rotary mowed crimson clover in November 2012.

Tillage:  Field was mulched using a common silage chopper.  Crimson clover was cut with a rotary mower.  Cabbage seedlings were planted using a no-till transplanter with a fluted coulter.

Plants Per Acre:  Cabbage transplants were set 18 inches apart in rows 30 inches apart = approximately 11,000 plants per acre.  (138 plants per row x 83 rows per acre = 11,454 plants per acre exactly).  80% field survival is common so final plant density = approximately 9,000 plants per acre.

Crop Variety:  Brassica oleracea cultivated variety “Golden Acre”.  This is an early season (58 day) round cabbage with small heads averaging 3 to 4 pounds each.

Common Weed Varieties:  Bull Thistle (Cirsium vulgare), Coffee Senna (Senna occidentalis), Hemp Sesbania (Sesbania exaltata), Morning Glory (Ipomoea species), Lambs Quarters (Chenopodium album), and Pigweed (Amaranthus blitum).

Weed Management:  Sunn hemp cover crop and crimson clover living mulch eliminated most weeds.  Field was better than 95% weed free so no herbicides were used for this trial.

Weed Spacing:  Approximately 2,200 weeds grew above the crimson clover living mulch = approximately 1 weed per 19.8 square feet.  Clumps of weeds were hand thinned to single weeds spaced about 4 to 5 feet apart.

Irrigation:  Overhead sprinkler irrigation, 1 to 2 inches applied each week as needed.

Organic Fertilizers:  Greensand and colloidal phosphate rock were broadcast with sunn hemp seed according to soil test recommendations.  Hemp seed was covered with 20 tons = 40,000 pounds of composted stable bedding.  Fish emulsion and liquid seaweed (Kelp) were used as starter fertilizers for cabbage transplants.

Insect Control:  Cabbage plants were sprayed with a harmless biological insecticide “BT” = Bacillus thuringiensis subspecies kurstaki strain SA-12 every 7 to 10 days throughout the growing season.  BT is a naturally occurring bacterial disease that kills caterpillars = juvenile forms of moths and butterflies.

Cabbage Yield:  Approximately 9,000 marketable heads were harvested.  Average head weight = approximately 3.375 pounds = 3 pounds 6 ounces (normal range is 3 to 4 pounds).  Yield per acre = approximately 30,000 pounds = 15 tons.

Production Costs:  $5,924 per acre (mostly for amortized irrigation system and farm machinery).

Cabbage Income:  30,000 pounds cabbage (9,000 marketable heads) x $0.35 per pound organic produce premium wholesale price = $10,500 gross income.

Net Income:  $10,500 gross income – $5,924 production costs = $4,576 net income from 1 acre of organic cabbage sold wholesale.  ($4,576 net income / $10,500 gross income) x 100 = 43.58% before tax profit.  ($4,576 net income / $5,924 production cost) x 100 = 77.2451 = 77% gross return on investment.

Agronomy Notes:

>>>  Most south Florida soils are coarse sands with very low humus content (often less than 2%).  Large amounts of organic matter must be added to these soils to keep them productive.  Cash crops must be rotated with soil building cover crops in order to maintain humus levels at 3% or above.

>>>  Muck soils also require large amounts of organic matter to replace humus lost to accelerated decomposition when swamps are drained.  Drainage and cultivation expose peat soils to large amounts of oxygen.  Rapid oxidation causes soil subsidence if organic matter is not replaced.

>>>  Root knot nematodes are serious agricultural pests in south Florida.  The most economical control method is to rotate cash crops with highly nematode-resistant cover crops like Sunn Hemp (Crotalaria juncea), Velvet Bean (Mucuna deeringiana), Cowpea (Vigna unguiculata), or Hairy Indigo (Indigofera hirsuta).

>>>  Sunn hemp, forage maize, and silage corn produce enormous amounts of organic matter for soil improvement (surface mulch or green manure).  Few farmers use hemp or maize as green manure or mulch crops because the plants must first be shredded in order to decompose quickly.  (If long-lasting mulch is desired, knock down cover crops with a roller-crimper then plant through dead mulch with a no-till seeder or transplanter).

>>>  Widely spaced weeds did not appear to have any negative effects on cabbage yield or quality.  Many cabbages growing near weeds were larger than those without any weed competition.  Light shade may be beneficial for cabbage growth.

>>>  Crimson Clover (Trifolium incarnatum) is often sown along Florida highways because it has large flowers.  Crimson clover makes good living mulch because it normally grows only 6 to 12 inches high.  Ideal living mulches grow short so they do not compete with crop plants for light.

Would You Like To Know More?  Please contact the Author directly if you have any questions or need additional information about using living mulches for weed control.

Please visit:  http://www.worldagriculturesolutions.com  — or —  send your questions to:  Agriculture Solutions, 413 Cedar Drive, Moon Township, Pennsylvania, 15108 United States of America  — or —  send an e-mail to:  Eric Koperek = worldagriculturesolutions@gmail.com

About the Author:  Mr. Koperek is a plant breeder who farms in Pennsylvania during the summer and Florida during the winter.  (Growing 2 generations each year greatly speeds development of new crop varieties).

2012 TOMATO AND SWEET POTATO POLYCULTURE TRIAL

This is a demonstration project:  A single field without controls or replications for statistical analysis.  The purpose of this trial is to explore possibilities before launching a full-scale research program.

Experimental Location:  Butler County, Pennsylvania, United States of America.  40.8606 degrees North Latitude, 79.8947 degrees West Longitude.

Climate:  Butler County has a temperate climate with cold winters.  Average annual temperature = 48.75 degrees Fahrenheit = 9.3 degrees Centigrade.  Average yearly rainfall = 41.85 inches = 106.299 centimeters.  Average yearly snowfall = 37 inches = 93.98 centimeters.  Average Last Spring Frost (36 degrees Fahrenheit) = 26 May.  Average First Fall Frost (36 degrees Fahrenheit) = 23 September.  Frost Free Growing Season = 119 days (about 4 months).

Experimental Plot Size:  1 acre = 208 feet x 208 feet (approximately).

Soil Type:  Heavy Clay Loam

Crop Rotation:  Organic herbicide (vinegar & citric acid) applied spring 2011 followed by broadcast seeded buckwheat (Fagopyrum esculentum) cover crop mowed at first flower then over-seeded with Dutch white clover (Trifolium repens).

Organic Herbicide:  10% Glacial Acetic Acid (liquid) + 5% Citric Acid (powder) + 83% Pure Water (rain water) + 2% Wetting Agent (surfactant) = 100% by weight.

Tillage:  Field rotary mowed prior to planting with a no-till transplanter.

Plants Per Acre:  Tomato transplants set 4 feet apart in rows 4 feet apart = 52 plants per row x 52 rows per acre = 2,704 tomato transplants per acre.  1 sweet potato transplant set every 2 feet between tomato plants in the row = 50 plants per row x 52 rows per acre = 2,600 sweet potato transplants per acre.

Crop Varieties:  Determinate, open pollinated, “Stake-Less” tomatoes (with thick upright stems).  “O’Henry” yellow sweet potato variety.

Predominate Weed Varieties:  Pigweed (Amaranthus blitum), Lambs Quarters (Chenopodium album), Bull Thistle (Cirsium vulgare), Foxtail Millet (Setaria species), and Morning Glory (Ipomoeae species).

Weed Management:  Organic herbicide, buckwheat cover crop, and Dutch white clover provided approximately 80% weed-free field for this trial.

Weed Spacing:  Clumps of broadleaf weeds were hand thinned to 1 plant every 3 feet.  Hand pruning weeds took the local scout troop (14 boys) about 4 hours.  Approximate weed density = 5,000 weeds per acre.

Irrigation:  Overhead sprinkler irrigation, 1 to 2 inches per week as needed.

Fertilizer:  Soluble nitrogen (62 pounds), phosphorous (76 pounds), potash (359 pounds), and magnesium (38 pounds) applied with irrigation water according to soil test recommendations.  Clover living mulch supplies about 100 pounds of nitrogen per acre.  2 tons of agricultural gypsum applied in spring 2011 to provide adequate sulfur for Dutch white clover.

Tomato Yield:  Approximately 51,000 pounds = 25.5 tons of marketable fruit per acre = 19 pounds per plant (pick-your-own).  High yield = 37 pounds per plant (controlled harvest).  Low yield = 7 to 8 pounds per plant (destructive harvest).

Sweet Potato Yield:  Approximately 10,000 pounds = 5 tons of marketable, first-grade roots per acre = 3.8 pounds per plant.

Planting Cost:  $4,025 per acre (mostly for amortized irrigation system and deer fencing).

Harvest Cost:  $1,810 per acre.  Sweet potato harvest took the local
Scout troop (14 boys) three days or approximately 300 hours to lift and sort roots by hand.

Marketing Cost:  $2,900 per acre (mostly for sales labor, newspaper advertisements, and post card mailings to previous customers).

Total Production Costs:  $4,025 planting cost + $1,810 harvest cost + $2,900 marketing cost = $8,735 total cost to grow and sell vegetables.

Tomato Income:  Fruits sold for canning at $0.25 per pound pick-your-own x 51,000 pounds harvested = $12,750 gross income.

Sweet Potato Income:  Roots sold for $1.50 per 5-pound bag.  10,000 pounds of number 1 roots harvested / 5 pounds per bag = 2,000 bags x $1.50 per bag = $3,000 gross income.

Net Income:  $15,750 income from vegetable sales – $8,735 cost to grow and market vegetables = $7,015 net income per acre.  $7,015 net income / $15,750 gross income = 0.4453968 x 100 = 44.5% profit.  [$7,015 net income / $8,735 cost] x 100 = 80.30% return on investment.

Agronomy Notes:

>>>  Dutch white clover living mulch normally provides 90% to 95% weed-free fields.  This season’s relatively poor 80% control rate is unexplained but provided an opportunity to examine the effect of weed spacing on crop growth and yields.  Widely spaced weeds (3 feet apart) appeared to have little or no effect on crop yields but did lower tomato hornworm populations — insecticides were not needed for the 2012 crop year.

>>>  Sweet potato yields were 50% less than normal because of low plant density; transplants were set only within tomato rows, not between tomato rows.

>>>  Buckwheat (Fagopyrum esculentum) is an ideal cover crop for non-chemical weed control.  Buckwheat grows very quickly (8 inches per week) to a maximum height of approximately 50 inches (4 feet 2 inches) in 6 weeks.  Seeds ripen at 10 to 11 weeks.  (Buckwheat must be cut at flowering to prevent reseeding).  Buckwheat’s fast growth and dense shade eliminate most weeds.

>>>  Sweet potatoes (Ipomoea batatas) make good living mulch:  They thrive in poor soil, require no insecticides, and established plants overrun most weeds.

Would You Like To Know More?  Please contact the Author directly if you have any questions or need additional information about using living mulches for weed control in vegetable crops.

Eric Koperek = worldagriculturesolutions@gmail.com

About The Author:  Mr. Koperek is a plant breeder who farms in Pennsylvania during the summer and Florida during the winter.  (Growing 2 generations per year greatly speeds development of new crop varieties).