LIVING MULCHES FOR WEED CONTROL

Long before there were herbicides, diesel tractors, or rotary cultivators, smart farmers learned to manage their weeds.  How did they do it?  Here’s how:

Living mulches suppress weeds, reduce soil erosion, enhance soil fertility, attract beneficial insects, and help retain soil moisture.  The best living mulches are low-growing, nitrogen fixing legumes.  Dutch White Clover (Trifolium repens) is a good example.

Before seeding clover or any other living mulch, remember that two crops are growing on the same land at the same time — the mulch crop and a cash crop.  Success requires careful management or both crops may fail.

All living mulches compete with their companion crops.  The extent of competition and consequential yield loss vary with management and crop type.  For example, under drought conditions shallow rooted crops generally show more yield loss than deep rooted crops.  Low or slow growing crops may be overwhelmed by more aggressive companion crops.

As a general rule, living mulches are not recommended where drought is expected because yield losses are too high.  However, many crops benefit from clover mulches during dry conditions — the clover shades the soil, retards evaporation, and increases humidity around the cash crop.

Transplanting Vegetables into Clover

Dutch white clover makes good living mulch for TRANSPLANTED vegetable crops provided:  (1)  Crops are irrigated,  (2)  Crops are fertilized, and  (3)  Crops are protected for the first 4 to 6 weeks from competition by the clover.

1 to 2 inches of water are needed weekly to grow both clover and vegetables without undue competition for moisture.  If water is limiting, it is best to drip irrigate the cash crop rather than water the entire field.

Nitrogen fertilizer is not often required for small grains but is recommended for maize, fruits and vegetables.  The reason is that clover fixes about 100 pounds of nitrogen per acre but these nutrients are not immediately available — they are retained by the living mulch.  Phosphorous and potassium should be applied according to crop requirements along with lime to correct soil acidity.  Dutch white clover needs sulfur and responds well to powdered agricultural gypsum at 2 to 3 tons per acre.

Dutch white clover grows only 6 to 8 inches high so there is little competition for light except when crops are young.  Mow a narrow strip where transplants will be set, or apply a circle of mulch around transplants to give crops a head start.  Once crops are established they will overgrow the clover and produce normal harvests.

Aggressive, fast-growing crops like tomatoes, peppers, okra, melons, squash, sweet potatoes, gourds & pumpkins all do exceptionally well when transplanted into Dutch white clover.  Cucumbers are slower growing and require extra mulch to protect them from early season competition with the clover cover crop.

Stake-less = self-supporting tomato varieties (with thick upright stems) grow well in Dutch white clover.  The living mulch keeps fruits clean and allows easy harvest even in rain-soaked fields.

Once established, Dutch white clover is an aggressive mulch crop that blots out most weeds.  Walk the fields and hand pull any weeds that escape the clover.  Alternatively, thin weeds to at least 1 yard or 1 meter apart.  Thinly spaced weeds will not significantly affect quality or yields of cash crops (but will provide food and shelter for beneficial insects).  Weedy fields often require little or no insecticides to control crop pests.

Direct Seeding into Standing Clover

Dutch white clover is not well suited to direct-seeded crops, especially those with small seeds or slow germination.

Common potatoes are an exception, especially if whole tubers are planted to establish the crop.  Roto-till a narrow strip just wide enough to get the seed potatoes in the ground.  After planting, over seed tilled rows with additional clover seed to maintain soil coverage.  The potatoes grow through the clover without trouble.  Fall potatoes (planted after hard frost in November) averaged 22.8 tons per acre when grown in irrigated Dutch white clover.  Adjacent non-irrigated fields averaged 16.4 tons per acre, the yield loss due to water competition.

Costa Rican Indians grow dry beans by broadcasting seed into the weediest fields available.  The weeds are then hand cut and left as mulch to protect the germinating beans.  Yields are low, only 400 to 500 pounds per acre, but there are no costs other than labor for planting and harvesting.

The same technique works with Dutch white clover.  Spring turnips broadcast into standing clover averaged 10.8 tons per acre when the clover was intensively grazed for 3 days and the seed stomped into the soil by sheep.  Adjacent plots mowed 1-inch high averaged 14.3 tons per acre.  Control plots (no grazing or mowing) averaged only 0.90 tons per acre because of intense competition from the clover.  In comparison, winter turnips (sown after the first snow) averaged 13.1 tons per acre.

These results demonstrate the importance of timing when sowing any small-seeded crop into Dutch white clover.  Ideally, seed should be sown when the clover is dormant.  The next best choice is “sow and mow” (or sow and graze).

Direct seeding into standing clover is not recommended unless the clover is knocked back to reduce competition with the primary crop.

In non-irrigated, non-fertilized fields, flint corn transplanted on 40 inch centers into mown Dutch white clover averaged 68 bushels per acre (along with 1,300 pounds of dried beans and 9,600 pounds of pumpkins).  Adjacent fields transplanted into Red Clover (Trifolium pratense) were overwhelmed and failed to make a crop.

Careful timing is essential when planting mixed crops into living mulches or bare soil.  For example, in a maize-bean-pumpkin polyculture, the primary maize crop should be at least 18 inches high (4 to 8 leaves) before beans or pumpkins are sown, otherwise the grain will be smothered by the companion crops.

Strip cropping combines the pest control advantages of polycultures with the high efficiency of mechanized agriculture.  For example, fields seeded into mown Dutch white clover with 4-row strips of maize alternated with equal width strips of dry beans and winter squash (maize-beans-maize-squash, et cetera) out yielded individual crops grown as monocultures.  The yield advantage for maize alone averages 15% when grown in narrow 4-row strips with other companion crops.  Yield increases from strip-cropping are attributed to better light penetration into the maize canopy, and reduced pest populations in the beans and squash.

Living mulches work especially well with intensive horticulture systems like truck farms and market gardens where careful management and judicious cultivation (including mulching and mowing) prevent the companion crops from overgrowing the cash crops.  When crops are planted into living mulches, entire farms (up to 25 acres) can be run with only a small rear tined roto-tiller and common lawn mower.  Leaving strips of hay, wildflowers, and clover between cash crops and around field borders creates a sanctuary for beneficial predatory insects that help keep pest populations under control.

Seeding Small Grains into Clover

Seeding small grains into living mulches works best when:  (1)  The companion crop is dormant or its growth retarded by mowing, grazing, or rolling, and  (2)  The grain crop is selected for a competitive growth habit.  Heirloom (non-dwarf) varieties usually pair well with understory legumes like Dutch white clover.  Alternatively, clover can be broadcast into standing grain that is well established (8 to 12 inches high).  Again, careful timing is essential to prevent the cover crop from overwhelming the cash grain.

In non-irrigated, non-fertilized fields, fall seeded wheat averaged 28.1 bushels per acre when broadcast into dormant clover.  Spring seeded wheat averaged 21.6 bushels per acre when the crop was “frost seeded” (planted in frozen soil).  Late spring “sow & mow” wheat averaged 19.9 bushels per acre while wheat broadcast into standing clover barely made a crop, only 3.4 bushels per acre.  In comparison, broadcast planted spring wheat top-seeded with clover when the wheat was 8 inches high averaged 15.4 bushels per acre.  To put these yields in perspective, conventionally drilled & cultivated spring wheat (without clover) averaged 39.7 bushels per acre (without irrigation) and 78.5 bushels per acre (with irrigation).

Extra water and fertilizer reduces competition for moisture and nutrients resulting in higher yields.  In irrigated, fertilized fields, fall seeded wheat averaged 70.4 bushels per acre when broadcast into dormant clover.  Frost seeded spring wheat averaged 56.5 bushels per acre, while late spring (sow & mow) wheat averaged 61.9 bushels per acre.  Spring wheat broadcast into standing clover failed to make a crop, while clover sown into standing 12 inch high wheat averaged 74.7 bushels per acre.

Sometimes Old Ways are Best

The clover-wheat-turnips rotation common during the Renaissance is a good example of how cover crops and living mulches can be integrated with modern low-till and no-till agriculture.  Typically, the clover cover crop was “hogged down” (uprooted by foraging pigs); this eliminated the need to plow and harrow.  Wheat was then broadcast by hand and the seed trod into the ground by sheep or cattle.  Turnips were broadcast into the wheat as the heads were filling out, and clover was broadcast over the turnips a few weeks before harvest.  This rotation reliably averages 40 bushels of wheat per acre under European weather conditions without the need for irrigation, synthetic fertilizer, machinery, fossil fuels, or agrochemicals.  (Favorable rain or irrigation boosts this average to 80 bushels per acre).  Low production costs more than compensate for modest yields, a primary consideration for most farmers operating on slim profit margins.

Thoughtful Weed Management

The key point to intelligent weed control is to disturb the soil as little as possible, just enough to get a crop into the ground.

Remember that weeds have evolved specifically to rapidly colonize bare soil.  The more soil is tilled, the more weeds are stimulated to grow.  Conventional bare earth agriculture invites weed invasions.  In order for crops to coexist with weeds and living mulches, a different approach is needed.  Ideally, crops should be over seeded or transplanted with the minimum possible disruption to both soil and surface vegetation.  Often, specialized equipment is needed.  For example:  Why dig a long furrow when only a few discrete holes are needed for seeding?

Without irrigation and fertilization, competition between living mulches and cash crops can reduce yields 50% or more.  Poor judgment (such as seeding at the wrong time) can result in crop failure.

Clearly, there is significant competition from living mulches; the question is whether the savings from reduced tillage and other costs are outweighed by observed yield reductions.  These differences may not be significant depending on how the crops are marketed.  For example, the premium for “organic” produce and the profits from artisan breads are substantial.  In this case, lower yields are offset by higher margins from specialty products sold to niche markets.

Agronomy Notes

>>>  Dutch white clover and winter wheat can be seeded at the same time.  Remember to plant only after the Hessian Fly Date for your area.  This technique works well with all winter grains.

>>>  Top seeding Dutch white clover usually requires a separation of 7 to 14 days between plantings (about the time it takes for the cash crop to germinate).  Slower growing crops need more time to become established.  For example, sweet corn should be at least 6 inches tall before over seeding with Dutch white clover.  Rule-of-Thumb:  Maize should have 4 to 8 leaves (16 to 24 inches tall) before top seeding with Red Clover (Trifolium pratense) or any other type of tall growing clover.

>>>  Organic herbicide may be used instead of mowing, grazing or cultivation to control Dutch white clover prior to planting a cash crop.  For example, a narrow strip of clover can be killed with herbicide before transplanting vegetables.  Use spray shields to prevent herbicide drift.  It is important to disturb as little of the living mulch as possible — kill just enough clover to get the crop established.  Removing too much plant cover favors weed growth.

>>>  If clover seed is unavailable or too expensive, use weeds as living mulch.  This technique works best with fast growing vine crops.  For example:  Choose the weediest field available then transplant melon seedlings on 10 to 12 foot centers.  Mulch each transplant liberally with straw or any other convenient material.  Mulch is necessary to keep weeds at bay only until vines begin to run.  Once started, vines will overgrow the nurse crop.  Melons thrive in the light shade of weedy fields.  As an added benefit, vines growing among weeds rarely have insect problems.

>>>  Red Clover (Trifolium pratense) seed is usually less expensive than Dutch white clover (Trifolium repens).  Sweet corn, popcorn, flint corn, flour corn, pod corn, and dent corns all grow well when planted with red clover.  Top seed = over seed maize with red clover at the last cultivation or when plants have 4 to 8 leaves.  The corn plants are tall enough (about 1 1/2 to 2 feet high) so that competition with the living mulch is minimal.

>>>  Any type of maize can be seeded directly into standing red clover using a no-till planter with a fluted coulter.  Two weeks later the field should be closely mowed with a swathing board and divider to keep the clover from falling on the planted rows of corn.  Alternatively, clover can be mowed directly before seeding.  Watch regrowth carefully; a second mowing may be required 2 weeks later.  No herbicides are needed if maize is planted into standing clover; nitrogen fertilizer is not required if clover has grown on the land for 1 or more years.

>>>  Maize is sensitive to drought, especially during pollination and when ears are filling out.  For highest yields apply 1 to 2 inches of water weekly to prevent moisture competition between crop and living mulch.

>>>  Planting hybrid sweet corn into standing red clover yields about 415 sacks per acre on average when sweet corn is seeded 8 inches apart within rows and 30 inches between rows = 25,979 seeds per acre.  Actual plants per acre is approximately 21,000 (17% field loss rate is common).  1 sack = 52 ears = 4 baker’s dozen = 21,580 marketable ears per acre.  Note:  Yield figures are discounted 50% for typical losses to crows, deer, groundhogs, coons, earworms, undersize or poorly pollinated ears, and other causes.

>>>  It is best to use pelleted seed when hand dropping or broadcast seeding into living mulches.  This is especially true for large-seeded crops like peas, beans, maize, melons, and squash.  Pelleted seeds greatly increase germination and stand establishment rates.

>>>  Seedling survival and stand establishment are optimal when planting is done with no-till equipment.  Expect 20% to 25% loss rates when broadcasting naked, unprotected seed into living mulches or other standing vegetation such as hay or weeds.

>>>  Biological agriculture is all about managing little details, for example, choice of companion crop:  Flour corn top seeded with sweet clover (Meliotus officinalis) was overwhelmed and failed to make a crop.  Flour corn planted with standard (tall) red clover yielded 37.4 bushels per acre.  Flour corn planted with medium red clover yielded 41.8 bushels per acre.  Flour corn planted with Dutch white clover yielded 47.6 bushels per acre.  Yield differences were entirely due to living mulch height.  Taller clovers compete more strongly with maize cash crops, especially when corn plants are young.

>>  Every farm has different soil and micro-climate.  Agronomic practices that work in one field may fail in another.  For best results, every farmer should maintain one or more research plots so that new methods can be tested and adapted to local conditions.

Related Publications

Managing Weeds as Cover Crops; Weed Seed Meal Fertilizer; Trash Farming; No-Till Hungarian Stock Squash; Planting Maize with Living Mulches; Organic Herbicides; Pelleted Seed Primer; Crops Among the Weeds; Forage Maize for Soil Improvement; Forage Radish Primer; and Rototiller Primer.

 For More Information

Readers who have any questions or require additional information about living mulches should contact the Author directly:

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

Most agricultural universities publish extensive literature on cover crops, nurse crops, living mulches, green manures, and crop rotation.  Contact your County agricultural extension agent or search the Internet for relevant publications.

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).

 

Advertisements

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).

CROPS AMONG THE WEEDS

As I sit here at my drafting table, the local code enforcement officer is looking askance at my “lawn” which is not mowed at the regulation height of 6 inches or less.  Instead, I have 2 research plots in front of my office, both planted with Peruvian land race potatoes.  One plot is mulched with stable bedding, the other plot covered with weeds up to 4 feet high.  The mulched potatoes are riddled with flea beetles; there are so many holes that the leaves look like window screening.  3 feet away, potatoes growing in weeds have only a few scattered holes in their leaves.  These results are typical of crops grown au naturel = in the wild.

When I was young, “good” farmers were judged by the straightness of their furrows and the cleanliness of their fields.  Bare earth and weed-free crops were the standard of good agricultural practice at that time.  Contrarian that I am, my fields were always less than pristine.  Many decades later, my crops are still a herbicide salesman’s nightmare.  The reason is that I have long since stopped trying to eradicate weeds.  Now, I manage them.  I encourage them.  I even plant weeds because I never seem to have enough wild plants in my fields.

Am I daft?  Certainly.  I am also wealthy because I don’t have big pesticide bills to pay.  My crops may not make record yields, but I am not aiming for a blue ribbon at the County Fair.  I measure success on the bottom line.  Who wants to spend $2,000 to plant a half acre of peppers?  I gladly trade low production costs over huge input bills.  I make more money by saving money.  As an added benefit, my customers can pick vegetables without worrying about being poisoned by agricultural chemicals.  I don’t need “organic” certification.  My customers pay me not to spray.  That’s good business any way you figure it.

Down the road I have a wilderness of citrus interspersed with live oaks, Spanish moss, and pangola grass.  It’s an old orchard that is long overdue for rotation, but it still makes me money because I spend almost nothing to maintain the trees.  Every now and then I spread some racetrack manure.  The irrigation system turns itself on and off.  The weeds grow 6 feet high.  Once a year, right before harvest, I mow between the trees — just enough so folks can pick the fruit.  Result:  No bugs on my trees.  Across the hedgerow of old-fashioned hibiscus, my neighbor clean cultivates his orchard and sprays with robotic frequency.  Every spider mite in the district comes to eat his leaves.  Chemical companies use his orchard to test new pesticides.  The mites don’t seem to mind; they eat insecticide like salad dressing.

Up the road are stake-less tomatoes (with thick, upright stems) transplanted into Berseem = Egyptian clover (Trifolium alexandrinum).  I used to walk the fields pulling any weed not blotted out by the clover.  Now, I don’t bother.  I let the weeds grow wild.  Occasionally, I thin the weeds if they grow too thick.  My fields look messy but I rarely see a hornworm.

Across the lane is my pride and joy: A jungle of weeds and melons.  The weeds grow over my head and the melons grow over the weeds.  The trick is to mulch the young melons (or mow the weeds) just until the vines start to run.  After the melons are well established, the crop fends for itself.  Vine crops thrive in the light shade cast by nearby weeds; the best fruits come from the weediest parts of the field.  Insect pests don’t like the broadleaf jungle so I never have to spray vine crops grown in weeds.

Intelligent Weed Management

Tired of getting sick every time you spray a field?  Use the following rules-of-thumb to create a healthy cropping system tailored to your local soil and climate:

>>>  Weeds are a type of living mulch:  Plants grown to reduce soil erosion, enhance soil fertility, attract beneficial insects, and help retain soil moisture.  Before planting into weeds or any other living mulch, remember that two crops are growing on the same land at the same time — the mulch crop and a cash crop.  Success requires careful management or both crops may fail.

>>>  All living mulches compete with their companion crops.  The extent of competition and consequential yield loss vary with management and crop type.  For example, under drought conditions shallow rooted crops generally show more yield loss than deep rooted crops.  Low or slow growing crops many be overwhelmed by more aggressive companion crops.  As a general rule, living mulches are not recommended where drought is expected because yield losses are too high.  However, many crops benefit from living mulches during dry conditions — the companion plants shade the soil, retard evaporation, and increase humidity.

>>>  Weeds make good living mulches for transplanted vegetable crops provided:  (1)  Crops are irrigated,  (2)  Crops are fertilized, and  (3)  Crops are protected for the first 4 to 6 weeks from competition by the weeds.

>>>  1 to 2 inches of water are needed weekly to grow both weeds and vegetables without undue competition for moisture.  If water is limiting, it is best to drip irrigate the cash crop rather than water the entire field.

>>>  Weeds grow quickly so there is often intense competition for light when cash crops are young.  Mow or roll a narrow strip where transplants will be set, or apply a circle of mulch around transplants to give crops a head start.  Once crops are well established they will usually hold their own.  If necessary, prune or thin weeds to increase light penetration for cash crops.

>>>  Roller-crimpers are better than mowers for weed management.  Mowing stimulates plant regrowth; crimping does not.

>>>  Aggressive, fast-growing crops like tomatoes, peppers, okra, melons, squash, sweet potatoes, gourds and pumpkins all do exceptionally well when transplanted into weeds.  Cucumbers are slower growing and require extra mulch to protect them from early season competition with weedy nurse crops.

>>>  As a general rule, broadleaf weeds make better nurse crops than wild grasses which are more competitive and difficult to manage.  Where weedy grasses are a problem, burn the fields or treat with organic herbicide before transplanting cash crops.

>>>  It is good practice to leave strips of meadow, weeds, wildflowers, cover crops, or other living vegetation between or around fields of cash crops.  These buffer strips act as refuges for beneficial insects needed to control crop pests.  The best refuge plants have small flowers so that good bugs can easily obtain pollen and nectar.  Examples include buckwheat, turnip, rape, clover, and any member of the botanical family Apiaceae = Umbelliferae = carrot family = Anise, Dill, Angelica, Chervil, Celery, Caraway, Coriander, Cumin, Carrot, Fennel, Lovage, Parsnip, and Parsley.

>>>  As a general rule, it is unwise to harvest fields all at once.  Divide fields into strips or parcels then harvest each sequentially.  Leaving un-harvested areas allows predatory insects to migrate from disturbed spaces.  The idea is to preserve a balance between predator and prey to prevent sudden population crashes.  Translation:  You want a resident population of good bugs waiting to eat any bad bugs that fly into your fields.

>>>  If weedy fields are unavailable for planting, seed conventional cover crops.  The best living mulches are low-growing, nitrogen fixing legumes like Dutch White Clover (Trifolium repens), Crimson Clover (Trifolium incarnatum), and Red Clover (Trifolium pratense).  Remember to inoculate legume seeds with compatible nitrogen-fixing rhizobium bacteria.

>>>  Where land is weak or vegetation sparse, plant weeds to restore soil health.  Spread weedy hay over sick fields.  Seed wildflowers adapted to your local climate.  Broadcast grain elevator screenings liberally; screenings are dirt cheap (often free) and contain many weed seeds.  If necessary, seed a nurse crop of common rye (Secale cereale) or millet (Panicum miliaceum) to help establish a vigorous weed population.

>>>  Where agriculture is problematic (bare soils, unfavorable climate, no water or fertilizer) it is best to seed mixed cover crops to mimic the diversity of naturally weedy fields.  Choose 2 cool season grasses + 2 cool season broadleaf plants + 2 cool season legumes + 2 warm season grasses + 2 warm season broadleaf plants + 2 warm season legumes.  Include 2 root crops (forage radish, turnip, or stock beet) to help break up compacted soil layers.  Total:  14 different cover crop species.  Plant at least 20 pounds of mixed cover crop seed per acre = 23 kilograms per hectare.

>>>  Weeds are nature’s band-aid; they are specifically evolved to rapidly cover disturbed soils.  Tillage encourages weed germination and stimulates weed growth.  Consequently, to manage weed populations avoid tillage whenever practical.

>>>  It is best not to disturb healthy populations of weeds or cover crops once they are well established.  Broadcast, transplant, or drill cash crops into surface vegetation.  Use equipment specifically designed for no-till planting on trashy, high-residue fields.  For surface (broadcast) planting, increase seeding rates to maximum levels or use clay pelletized seed.  (Pelleted seeds greatly increase plant survival).

>>>  Weeds are most efficiently controlled by using the natural competitive abilities of crop plants.  For example, top seed forage radish (Raphaus sativus variety longipinnatus) over oats when they start to head out.  The radish understory crop grows slowly until grain harvest.  After oats are combined, radish growth explodes quickly covering the field and blotting out nearly all competing plants.  Weeds never have a chance to get established.  Top seeding into standing vegetation is a great way to grow small-seeded crops without using herbicides.

>>>  Grind weed seeds into flour and use like cotton seed meal as a cheap, slow-release organic fertilizer.  1 ton of weed seed meal supplies approximately 54 pounds of nitrogen, 18 pounds of phosphorous, and 18 pounds of potassium (2.7% nitrogen, 0.9% phosphorous, and 0.9% potassium by weight).  Note:  There is no standard analysis for weed seed meal.  NPK values vary depending on the mixture of species in local samples.

>>>  Every farm has different soil and micro-climate.  Agronomic practices that work in one field may fail in another.  For best results, every farmer should maintain one or more research plots so that new methods can be tested and adapted to local conditions.

>>>  Effective weed management requires careful observation and close attention to detail.  Every farmer must become a weed biologist.  Timing of field operations is critically important.  Planting 2 weeks earlier or later can result in stunning success or dismal failure.  Continuous experimentation  is needed to develop weed control programs for each individual crop, field, and farm.

Organic No-Till Weed Control

Conventional no-till agriculture relies on synthetic herbicides to control weeds.  Following no-till method uses an all-natural herbicide substitute made from acetic acid (vinegar) and citric acid (lemon juice).  Combination makes a non-selective vegicide that works like Roundup (glyphosate) to kill both grasses and broadleaf weeds.

Organic Herbicide Formula By Weight For Farming

10%          Glacial Acetic Acid (liquid)               100 grams

5%            Citric Acid (powder)                         50 grams

83%          Water                                                 830 grams

2%            Wetting Agent (surfactant)            20 grams

100%       TOTAL PARTS BY WEIGHT        1,000 grams

This is a non-selective herbicide = kills everything.  Wetting agent is essential for herbicide to stick to leaves.  For best results, apply herbicide on a warm, sunny day when weed leaves are dry.  Herbicide works best on annual broadleaf weeds and grasses 6 inches or less in height.  This is a burn down herbicide; only surface vegetation is killed.  Herbicide will not kill perennial weeds with deep taproots or grasses with growing points below soil surface.  Herbicide is not translocated to roots or other plant parts.  Weeds die from water loss through their leaves.  Caution:  Glacial acetic acid (industrial strength vinegar) is strongly corrosive.  Protect skin and eyes from acid.  Wear gloves and goggles when mixing and spraying herbicide.  Rinse with pure water if necessary.

Organic Herbicide Formula By Volume For Gardening

This formula uses common vinegar (5% acetic acid) and bottled lemon juice (3% to 8% citric acid) that can be purchased from neighborhood grocery stores.

1,250 milliliters          Common White Vinegar          5 Cups

250 milliliters            Bottled Lemon Juice                 1 Cup

30 milliliters              Dish Washing Detergent          2 Tablespoons

1,530 milliliters        TOTAL VOLUME                     6 1/8 Cups

Above concentration will kill annual broadleaf weeds and grasses 6 inches or less in height.  For best results apply herbicide on a warm, sunny day when weed leaves are dry.

Organic No-Till Procedure

This technique works best with small grains, turnips, and other crops that can be broadcast rather than drilled.

(1)  Select ground with good weed or crop cover.  Weeds or nurse crop will be used as mulch to protect germinating cash crop.  (2)  Broadcast seed into standing weeds or cover crop.  (3)  Kill weeds or nurse crop with organic herbicide.  (4)  Mow weeds or nurse crop when dead.  (5)  If desired, top seed established crop plants with Dutch White Clover (Trifolium repens), Red Clover (Trifolium pratense), Crimson Clover (Trifolium pratense),  or other low growing legume.

Mulch-In-Place

>>>  It is impractical to mulch large fields by hand because the volumes required are too large.  The solution is to grow a mulch crop then kill it by mowing, crimping, or spraying with herbicide.  Seeds or transplants are then set through the surface mulch.

>>>  8,000 to 10,000 pounds of straw mulch per acre are needed to achieve 90% weed control.  A crop of rye grain (Secale cereale) 5 to 6 feet high normally yields 4 to 5 tons of biomass per acre.  Most mulch-in-place systems use grass crops because cereal straw decomposes slowly.  Broadleaf cover crops rot faster leaving holes in the mulch through which weeds grow.

>>>  Mowed fields are best transplanted by hand because no-till planters often get clogged by loose plant materials.  Sickle-bar mowers are better than rotary or flail mowers because they do not chop or scatter the mulch.  Good weed control requires a dense layer of long straw which blocks sunlight and acts as a physical barrier to weed emergence.

>>>  Rolling down a cover crop is faster than mowing.  Roller-crimpers are cheaper than mowers and cost less to operate.

>>>  Roller-crimped fields are ideal for no-till seeders and transplanters.  Always work “with the grain” = in the same direction as the cover crop or weeds are rolled.  Never work against or across the grain or surface mulch will clog planting machinery.

>>>  Mulch crops are best killed when in full flower or early seed set.  Earlier harvest reduces mulch yields and increases chances of regrowth.  (You do not want the cover crop competing with the cash crop).  Late harvest risks reseeding by the mulch crop.  (Seed carryover between seasons turns a good mulch crop into a bad weed problem).  For example:  The best time to kill cereal rye is when the seeds are in their milk or soft dough stage.  Harvest at this time guarantees maximum straw yield and zero regrowth.

>>>  It is good practice to top seed a low growing legume like Dutch White Clover (Trifolium repens) immediately after seeding or transplanting cash crops.  Clover plants fill any holes in the mulch and increase biodiversity in the field.

>>>  To make your own roller-crimper, start with a steel cylinder 12 to 24 inches diameter, like a lawn roller.  The cylinder can be any convenient length; 8 to 10 feet long is the smallest roller recommended for efficient commercial farming.  Weld dull blades of 1/4 inch steel to the roller.  Each blade should be 4 to 5 inches high.  Space blades 7 to 8 inches apart.  Angle blades across the cylinder in a wide V-shape like a chevron; this prevents roller from bouncing around and greatly improves crimping effectiveness.  Mount roller on frame attaching to a 3-point hydraulic hitch on tractor front.  When finished, roller and frame should weigh 3,000 pounds; this weight is necessary to thoroughly crimp mulch plants so they do not regrow.  If desired, roller can be designed to hold water ballast so that weight can be increased for tough-stalked mulch crops like forage maize.  Detailed plans for roller-crimpers are available from the Rodale Institute = http://www.rodaleinstitute.org

Medieval No-Till

Plowing in the Middle Ages was hard, slow work.  Heavy wood plows were ponderous, inefficient, and difficult to turn.  A man with a team of 2 oxen took 3 whole days to plow and harrow a small 1-acre field just 22 yards wide x 220 yards long.  The alternative was even worse:  Digging by hand was back-breaking labor requiring at least 30 days to till 1 acre with spade or fork.  It did not take long for farmers to figure out easier ways to grow crops.  The Dutch were the first to apply the new agricultural technology which married free-range pig ranching with a clover-wheat-turnips rotation:

In spring, fence off plot of Dutch White Clover (Trifolium repens) and turn in swine.  (Pigs like Dutch clover because it is sweet.  Do not put rings in hogs’ snouts or they will not be able to root).  Pigs “plow” soil like a rototiller, uprooting all vegetation.  Broadcast spring wheat onto pig-tilled earth then drive sheep back and forth across land.  Sheep stomp wheat seeds into ground.  When wheat starts heading out (or at least 2 weeks before harvest) broadcast turnip seed over standing grain.  After wheat is cut, fast-growing turnip leaves carpet field overwhelming competing plants.  About 2 weeks before turnip harvest broadcast clover seed over standing foliage.  When roots are lifted, young clover plants blanket field, blotting out most weeds.  Clover cover crop protects and fertilizes soil until following spring when rotation cycle is repeated.

On a typical farm in northern France or upstate New York, no-till clover-wheat-turnips reliably yields 40 bushels of wheat per acre (2,400 pounds per acre = 2,694 kilograms per hectare) without hybrid varieties, irrigation, tractors, diesel fuel, chemical fertilizers, synthetic herbicides, insecticides or fungicides.  (Note:  This rotation works equally well with Oats = Avena sativa, Barley = Hordeum vulgare, Rye = Secale cereale, or Millet = Panicum miliaceum).

Sow-And-Go

No-Till agronomy is not a new idea; no-till was practiced in the Middle Ages (and probably earlier).  Then, no-till was used mostly by small farmers who did not own draft animals — or — as an emergency measure practiced only when primary crops failed or when an army swept through the district (stealing all of the food and farm animals).  Medieval records indicate that no-till was a desperation technology often used by peasants to prevent starvation:

Foul weather prevailed through spring.  Fields could not be plowed so farmers sowed in the rain, scything weeds to hide the seed from birds and mice.  By Divine Grace a crop was made, only two thirds of normal harvest but sufficient to forestall general famine among the tenants.  Tithes were not collected this autumn and the Church distributed alms and acorns to the poor.  Annals of the Abbey of Saint Marien [Lake Constance, Germany] Anno Domini 1340

How To Do It:  Find the weediest field possible.  Broadleaf weeds are best and thistles best of all.  (Thistles indicate fertile soil).  Broadcast seed directly into standing weeds.  (Pelleted seed greatly increases seedling survival, especially for large-seeded crops like peas and beans).  Mow down weeds with a scythe (or use a lot of people with sickles or machetes).  Cut weeds act as mulch for germinating crop.  Pray for rain.  Come back at harvest time and hope for the best.  Yields are low but surprisingly economic (because there are no costs other than seeding and harvest).

Medieval No-Till Yields of Dry Peas:  Poor Crop:  4 to 5 bushels = 250 to 300 pounds per acre.  Average Crop:  6 to 8 bushels = 400 to 500 pounds per acre.  Good Crop:  10 to 13 bushels = 600 to 800 pounds per acre.

Medieval No-Till Yields of Spring Wheat:  Poor Crop:  4 to 6 bushels = 275 to 400 pounds per acre.  Average Crop:  7 to 10 bushels = 440 to 650 pounds per acre.  Good Crop:  11 to 17 bushels = 660 to 1,040 pounds per acre.

Sow-and-Go planting is ancient technology adapted for modern machinery.  In India it is called Zero Budget Natural Farming.  Australians use the term No-Kill Cropping.  Some call it Do Nothing Farming, Zero Petroleum Agriculture, or Minimum Effort Agronomy.  Less charitable souls use the term Subsistence Agriculture.  Regardless of label, the principle remains identical:  Sow seed (without tillage or any other investment) then forget about the crop until harvest time.  Small fields are hand planted, large areas seeded with no-till drills.  The trick is to sow when plants normally drop their seeds, usually during the dry or cold season when weeds are dead or dormant.  Native vegetation is left standing; this is necessary to prevent erosion, feed soil organisms, aid water infiltration, slow wind speed, provide shade, increase humidity, improve biodiversity, and trap snow.

Sow-and-Go agronomy is particularly suited where climate or soils are problematic, especially drought-prone, semi-arid regions like Australia and the western prairies of North America.  Old farms, hay fields, pastures, range lands, or any relatively flat area of grass or weeds is suitable for Sow-and-Go planting.  For best results, no-till planters should have razor sharp coulters to slice through surface vegetation, chisel tines or cultivator shoes to open a narrow slot for seeding, and double press wheels to ensure good seed to soil contact.  Minimal soil disturbance is essential for success.  Pelleted seeds are recommended for broadcast planting or land restoration.

In years with good rainfall, Sow-and-Go crops typically yield 60% to 70% of conventionally grown plants.  Translation:  Expect 40% yield losses compared to full-tillage or herbicide treated crops.  Higher yields are sometimes possible on particularly deep or fertile soils.  Drilled crops generally yield more than broadcast seeded crops, especially when seeds are large, weather is dry, or when planting naked seeds.

Sow-and-Go cereal culture is the wave of the future.  Farmers should set aside a few acres to test this new biological technology which can be used to grow any kind of small grain including pseudo-cereals like amaranth (Amaranthus caudatus), buckwheat (Fagopyrum esculentum), and quinoa (Chenopodium quinoa).  If weedy fields are not available, seed mixed cover crops of annuals or perennials then plant into this artificial prairie.  Soil fertility and structure improve rapidly under continuous vegetation, especially if legumes and root crops are included in the mix.  Each year planting becomes easier and yield potential increases.  Results are often surprising and cannot be easily predicted because of complex interactions between many species in a new, “designer ecology”.  Careful observation, precise timing, and constant adjustment are needed to “tweak” the system to favor particular crops.  Real ecological management is required — the very opposite of robotic, spray-by-calendar conventional agriculture.  Sow-and-Go farmers are never bored; they are always making new discoveries in their fields.

Related Publications

Managing Weeds as Cover Crops; Weed Seed Meal Fertilizer; Trash Farming; No-Till Hungarian Stock Squash; Planting Maize with Living Mulches; Organic Herbicides; Pelleted Seed Primer; Living Mulches for Weed Control; Forage Maize for Soil Improvement; Forage Radish Primer; and Rototiller Primer.

For More Information

Readers who have any questions or require additional information about growing crops in weeds should contact the Author directly:

Please visit:  http://www.worldagriculturesolutions.com  — or —  send your questions to:  Eric Koperek, Editor, World 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 summer and Florida over winter.  (Growing 2 generations yearly speeds development of new crop varieties).

FORAGE MAIZE FOR SOIL IMPROVEMENT

What Is It?     Forage maize is a type of corn (Zea mays) grown to provide fresh fodder = green chop for grazing animals like dairy cows and beef cattle.  Forage maize is specially adapted for dense plantings and maximum yield of leaves and stalks per acre.  Fast growth, dense shade, and high tonnage make forage maize an ideal cover crop for weed control, surface mulch, and green manure.

Crop Height:     Forage maize typically grows 12 to 15 feet tall.  High growth enables forage maize to kill the most aggressive weed vines.

Growth Rate:     Under favorable conditions forage maize grows 2 to 2.5 inches per day = 1.8 to 2 tons of biomass (leaves & stalks) per acre per week.  Fast development allows forage maize to out-compete most temperate and tropical weeds.

Plants Per Acre:     Unlike silage corn that has ideal populations of 30,000 plants per acre (for milk production) or 40,000 plants per acre (for maximum biomass), forage maize is planted at much higher densities:  80,000 to 100,000 plants per acre.  Tall growth and close spacing create deep shade that kills most weeds.

Plant Spacing:     9 inch x 9 inch equidistant spacing = 77,440 plants per acre.  8 inch x 8 inch equidistant spacing = 98,010 plants per acre.  If rows are spaced 15 inches apart then plants must be spaced 4 to 5 inches apart within rows.  166 rows per acre (15 inches between rows) x 624 plants per row (4 inches between plants) = 103,584 plants per acre.  166 rows per acre (15 inches between rows) x 499 plants per row (5 inches between plants) = 82,834 plants per acre.

Seeding Rate:     Forage maize has an average seed weight of approximately 100 seeds per ounce or 89,600 seeds per bushel = 8 gallons = 56 pounds.  At 80% standard field survival, drill or broadcast 1.25 bushels = 10 gallons = 70 pounds of forage maize seed per acre to obtain a final population of 89,600 plants per acre.

Hybrid Seed:     There is no advantage to planting hybrid forage maize seed.  Open pollinated seed is significantly less expensive and equally effective for animal fodder, weed control, surface mulch, or green manure.  Note:  Brown mid rib forage maize varieties are preferred for green chop because they are more digestible.

Broadcast Seeding:     Most corn is planted with a grain drill or seeder.  Forage maize can also be broadcast with a rotary spreader.  For best results, mix live seed with feed corn that has been baked in shallow 2-inch deep pans to kill the seed.  (2 hours baking at 300 de3grees Fahrenheit is sufficient).  Dilution of live seed with non-viable filler provides extra volume for easier and more accurate distribution.  Divide seed mixture into 2 equal portions.  Seed up and down the length of the field then broadcast from side to side.  Seeding from 2 directions gives the most uniform plant spacing.  Rototill or harrow seed 2 inches deep then irrigate to firm and moisten seedbed.

Yield:     Forage maize reliably produces 18 tons = 36,000 pounds per acre of biomass at 65% moisture content in 70 days = 10 weeks (from seeding to harvest).  Yields exceeding 30 tons per acre are commonly obtained from long-season crops of 120 days or more.

Fertilizer:     Apply fertilizer according to soil test recommendations for silage corn of equivalent tonnage.  To reduce fertilizer cost plant forage maize following a nitrogen-fixing cover crop like Sunn Hemp (Crotalaria juncea) or Red Clover (Trifolium pratense).  Either organic or synthetic fertilizers are equally effective; nutrients are most efficiently applied in irrigation water.

Nutrients Required Per Ton Of Biomass:

Fertilizer Element               Pounds of Fertilizer Needed                                                                                                                           Per Ton of Forage Maize Harvested Per Acre.

Nitrogen                                  10.36

Phosphorous                         1.6

Potassium                             9.2

Sulfur                                    0.92

Zinc                                      0.02

A 30-ton expected yield of forage maize per acre requires 30 x 10.36 = 310.8 pounds of nitrogen, 30 x 1.6 = 48 pounds of phosphorous, 30 x 9.2 = 276 pounds of potassium, 30 x 0.92 = 27.6 pounds of sulfur, and 30 x 0.02 = 0.60 pound of zinc per acre.  Note:  Remember to subtract nitrogen fixed by preceding legume cover crop (if any).

Irrigation:     Forage maize needs 1 to 2 inches of water weekly for optimum growth rate and yield.  Adequate soil moisture is essential for quick germination and rapid crop development.  Forage maize seedlings must have sufficient water in order to outgrow weeds.

Weed Control:     Spray weeds or cover crop with organic herbicide (10% glacial acetic acid liquid + 5% citric acid powder + 2% wetting agent + 83% pure water = 100% by weight.  Wetting agent is necessary so herbicide sticks to leaves).  If desired, dead weeds or cover crop can be mowed to facilitate planting.  Alternatively, use a roller-crimper to kill vegetation.  Seed forage maize with a no-till planter then irrigate promptly to speed germination.  Forage maize will outgrow most weeds.  Once maize reaches 6 inches high the crop can fend for itself.

Harvest:     Forage maize can be harvested whenever convenient; it is not necessary for ears or grain to develop.  (Forage maize can even be left standing in the field over winter).  Harvest at any season is most efficient with a common forage chopper.  If desired, harvester discharge chute can be modified to deposit shredded vegetation into windrows for mulching.  Alternatively, green chop can be blown directly into a wagon, truck, or mulch spreader for transport and application in another field.  Forage maize can also be flattened with a roller-crimper or cut with a sickle-bar mower to make dense, slowly decomposing mulch ideal for vine crops.  (Set transplants immediately then top-seed with a low-growing clover).

Green Manure:     Forage maize must be shredded or it will not rot quickly.  Do not plow stalks into the soil; whole stalks will take 2 or more years to decompose.  For best results, harvest forage maize with a silage chopper.  Disperse shredded vegetation evenly, spread fields with phosphate rock or other fertilizers, then incorporate soil amendments by rototilling or disking 8 inches deep.  If a rototiller or tandem disk harrow is not available, double plow using a common moldboard plow.  (Bury green manure under the soil then plow it back up again).

No-Till Farming:     Leave forage maize (shredded, rolled or mown) and broadcast fertilizers on soil surface.  Do not plow, harrow, or cultivate as this will stimulate weed germination.  Over-seed surface mulch with grain, turnips, or other small seeded crop; seeds will work their way into the soil.  Irrigate immediately to speed germination.  When cash crop reaches 6 inches high top-seed with Dutch White Clover (Trifolium repens) or other low-growing legume.  Note:  Winter grains and clover can be seeded at the same time.  Alternatively, use a no-till planter to drill seeds through the mulch.  (Tip:  Always work “with the grain” = in the same direction as the mulch is rolled or mown.  Seeding cross-grain will clog seeder with mulch).

Cost per Acre:     Forage maize costs about $18 per ton to make a crop in Butler County, Pennsylvania.  At 2015 prices, a 30-ton forage maize crop costs approximately $540 per acre for seed, fertilizer, fuel, and other out-of-pocket expenses.  This works out to $0.009 = 0.9 cents per pound of harvested vegetation.

Would You Like To Know More?     Please contact the Author directly if you have any questions or need additional information about using forage maize for weed control, surface mulch, or green manure.

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 speeds development of new plant varieties).