STRIP CROPPING PRIMER

What Is It?     Strip cropping is a natural way to control pests without using insecticides.  Unrelated crops are grown in narrow strips to increase biodiversity and maximize edge effects.  Beneficial insects flourish and eat harmful bugs.

The Edge Effect:     Life increases proportionately to the boundary area between different environments.  For example, a meadow and a hedgerow are unique ecologies.  Each has its own mixture of species.  There is an abundance of food and shelter along the edge where the two environments meet.  Interaction along this edge promotes large populations and increased diversity.

Ecology Math:     Square fields have less edge than rectangular fields.  For example, a square field measuring 300 feet on each side has 1,200 feet of edge (300 feet per side x 4 sides = 1,200 feet).  Take the same field and stretch it into a rectangle 100 feet wide x 900 feet long.  Both fields have the same area (90,000 square feet) but the rectangular field has 2,000 feet of edge (900 + 900 + 100 + 100 = 2,000 feet).  The perimeter of the rectangular field is 40% larger than the square field.  More edges = more food and habitat = more species and larger populations.  Hunters understand this instinctively.  Long, narrow fields have more browse (twigs and buds) along their perimeter.  More hedgerow = more browse = more food = more deer.

Agricultural History:     Farming in the Middle Ages was not easy.  Wood plows were heavy and difficult to turn.  The solution was to make long, narrow fields.  Long fields required fewer turns.  Each field was one “furrow” long = 1 furlong = 1/8th mile = 220 yards long x 22 yards wide = 4,840 square yards = 1 acre.  A man with a team of oxen took a whole day to plow 1 acre.  Adjacent fields were planted to unrelated crops, for example:  Peas, Wheat, Turnips, and Pasture.  Narrow strips and diverse crops increased edge effects supporting large populations of beneficial insects.  The good bugs ate the bad bugs.

Agroecology:     Wind the clock back to when knights went clanking around in armor.  Northwest France (Normandy) was divided into thousands of little fields surrounded by hedgerows.  Each field measured about 1 1/4 acres.  This mixture of small fields and hedgerows is called bocage.  The bocage landscape contains hundreds of miles of biological edges = vast populations of predatory and parasitic insects.  Modern farmers in the bocage rarely have pest problems.  Significant outbreaks occur about once every 20 years and are mostly self-correcting without insecticides.

“Altering the geometry of fields costs nothing and can reduce or eliminate pesticide use.”

Practical Polyculture:     Plant 4 rows of corn then 4 rows of soybeans.  Repeat this pattern across fields and farms following land contours.  Result:  Pests go down 50% and corn yields go up 15% (because of increased light penetration into the crop canopy).

  • Alternate tall and short crops.  Insect pests do not like fields with mixed light and shade.  Example:  Sunflowers — Alfalfa — Barley — Lentils
  • Adjust strip widths to fit planting and harvesting equipment.  Try to keep strip widths as narrow as mechanically practical.  Narrow strips better control insect pests.  Plant strips no wider than 200 feet to encourage rapid movement of beneficial insects into fields.  Example:  Hay (150 feet) + Soup Beans (75 feet) + Safflowers (75 feet)
  • Plant adjacent strips to unrelated crops.  Plant as many different crops as economically practical.  Diverse crops reduce insect pests and spread market risk.  Example:  Wheat — Peas — Flax — Soy Beans — Barley — Alfalfa
  • Seed grains and legumes together.  Legumes fix nitrogen, protect soil and control weeds.  Example:  Winter Wheat + Dutch White Clover  — or —  Field Corn + Red Clover  — or —  Oats + Forage Peas  — or — Winter Rye + Winter Vetch
  • Alternate legumes with non-legumes.  Legumes improve soil, feed earthworms and attract beneficial insects.  Example:  Canary Seed — Lentils — Barley — Soy Beans — Wheat — Field Peas — Flax — Alfalfa
  • Plant windbreaks not closer than 50 feet nor farther than 150 feet apart.  Windbreaks increase biological diversity and help crops grow better.  Windbreaks do not have to be great belts of trees.  A single row of shrubs or perennial pampas grass will slow wind and increase crop humidity.  Example:  Trees (25 feet wide) + Cropland (150 feet wide)  — or —  Shrubs (10 feet wide) + Cropland (100 feet wide)  — or — Pampas Grass (3 feet wide) + Cropland (50 feet wide)
  • Alternate strips of native weeds with cropland.  Space weed strips not farther than 200 feet apart.  Weeds should comprise at least 5% to 10% of total cropland.  Native weeds are essential to provide food and shelter for beneficial insects.  Example:  Weed Strip (15 feet) + Cropland (135 feet)
  • Plant several varieties of the same crop together.  Choose varieties that have the same harvest date.  Varieties can be mixed or drilled in separate rows.  Alternatively, plant similar species that ripen together.  For example:  Winter Wheat + Winter Rye.  Genetic diversity reduces the chances of crop failure due to weather, disease or insects.

Try This On Your Farm:     Divide big fields into narrow strips and watch your pest problems go away.  Strip cropping combines the biological advantages of polycultures with the economic efficiency of farm machinery.

Related Publications:     Maize Polyculture Trial 2007-2016; Managing Weeds as Cover Crops; Trash Farming; No-Till Hungarian Stock Squash; Planting Maize with Living Mulches; Living Mulches for Weed Control; 2012 Tomato and Sweet Potato Polyculture Trial; Crops Among the Weeds; and The Edge Effect.

Would You Like To Know More?     Contact the Author directly if you have any questions or need more information about polycultures or strip cropping.  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:  http://www.worldagriculturesolutions.com

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

 

 

Advertisements

MAIZE POLYCULTURE TRIAL 2007-2016

Abstract:     This experiment measures the productivity of a 3-species polyculture of flint corn, pole beans, and winter squash.  Heritage varieties are grown in traditional hills with fish fertilizer.  Areas between hills are untended and covered with native weeds. 

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:     1/4 acre = 10,890 square feet exactly = 104 x 104 feet approximately = 10,816 square feet nominal measure.

Experimental Design:     A 1/4-acre plot was planted each year.  Crops were not rotated; hills were replanted each year in keeping with traditional Indian practice.  The experiment was repeated for 10 years (to account for weather variability between years).  10 data sets ensure reliable averages for accurate conclusions.

Soil Type:     Heavy Clay Loam

Crop Rotation:     Field was fallowed in native weeds for 7 years prior to experiment.  Hilled crops were NOT rotated.  Hills were replanted each year following traditional Indian methods.  (Historical sources record that native farmers practiced long rotations.  When soils became exhausted, hills were moved or fields abandoned).

Tillage:     There is no easy way to make Indian planting hills using conventional farm machinery.  Consequently, tree planting augers were used to dig holes 2 feet wide x 2 1/2 feet deep.  Holes were then refilled with excavated soil to make traditional mounds approximately 1 foot high.  Augers save considerable hand labor while preserving weed ground cover.  (The idea is to use native weeds as a multi-species cover crop.  Cash crops are planted in hills surrounded by weeds.  The weeds protect crops from insect pests).

Plant Density:     Hills were equidistantly spaced every 4 feet on center = 26 rows x 26 hills within each row = 676 mounds in the 1/4 acre research plot.  Each hill contained 4 maize plants seeded evenly around a circle 1-foot diameter.  When maize plants reached 2 feet high (4 to 8 leaves), 1 pole bean seed was planted 3 inches from each maize stalk.  676 hills x 4 maize plants per hill = 2,704 maize plants per 1/4 acre.  676 hills x 4 bean plants per hill = 2,704 bean plants per 1/4 acre.  Squash plants were set every other row and every other mound within alternate rows  = 8 feet x 8 feet apart = 13 rows x 13 mounds within each row = 169 squash plants per 1/4 acre.

Plants Per Acre:     10,816 maize plants; 10,816 bean plants; and 676 winter squash plants per acre.  For ease of comparison, yields are summarized in pounds per acre.

Transplant Size:     Squash transplants were 4 weeks old.  All plants were about 4 inches high.  Transplants were grown in 3 1/2 inch interior diameter peat pots filled with crumbled, dried cow manure.

Crop Varieties:     Floriani Red Flint Corn; Scarlet Runner Pole Bean; and Waltham Butternut Winter Squash.

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

Weed Management:     No attempt was made to eradicate weeds.  Fields were mowed as close to ground level as practical immediately prior to seeding and transplanting.  Cut weeds were used as mulch for planting mounds, about 2 1/4 pounds (dry weight) of weed mulch per hill.  Squash vines overwhelmed most weeds.  Wild morning glory vines were the most difficult to control and some hills (about 15 percent on average) were nearly overrun.  Hand pruning was necessary to prevent crop loss.  A second mowing (when squash vines started to run) effectively suppressed weed growth, but squash and weeds battled for dominance in the “No Man’s Land” between hills.

Irrigation:     Crops were NOT irrigated, in keeping with traditional practice.  There is no historical record of Eastern North American Indians irrigating their crops, probably because there was little need to do so and also because native farmers did not have effective irrigation technology.  Carrying water in gourds, bark buckets, and clay pots is grueling labor.

Insect Control:     No active measures were taken to control insect pests.  Native weeds provided food and shelter for many beneficial insects that protected crops.

Fertilizer:     Fresh trash fish or fish scraps were too difficult to obtain in quantity, so fish meal (10 percent nitrogen, 5 percent phosphorous, 0 percent potassium) was used instead.  Each maize and squash plant received 1/3 cup (1.66 scale ounces) of fish meal mixed with the soil at planting.  This is the approximate equivalent of 119 pounds of available nitrogen and 59 pounds of phosphorous per acre.  Potassium was provided in the form of wood ashes, 6 scale ounces top dressed over each hill when squash vines were transplanted = about 1/2 ton (1,000 pounds) per acre = 70 pounds of available potash per acre.  (Fertilizing crops was NOT a common practice among North American Indians.  Native farmers learned these techniques from Europeans.  For example:  In colonial times, French farmers in Normandy fertilized their fields with herring).

10-Year Maize Yield Summary:     2,997.7 pounds per acre = 1.49885 tons per acre = 53.5 bushels per acre.  Range = 1,853 to 3,960 pounds per acre = 33.08 to 70.71 bushels per acre.  Average Yield per Plant = 4.43 ounces.  1 bushel of clean, shelled corn = 56 pounds.

10-Year Bean Yield Summary:     520.8 pounds per acre = 0.2604 ton per acre = 8.68 bushels per acre.  Range = 336 to 688 pounds per acre = 5.6 to 11.46 bushels per acre.  Average Yield per Plant = 0.048 pound = 0.768 ounce.  1 bushel of clean, dried beans = 60 pounds.

10-Year Winter Squash Yield Summary:     7,293.6 pounds per acre = 3.6468 tons per acre.  Range = 5,412 to 8,776 pounds per acre = 2.706 to 4.388 tons per acre.  Average Fruits per Acre = 3,000.  Average Fruit Weight = 2.43 pounds = 2 pounds 6.88 ounces.  Average Yield per Plant = 10.78 pounds = 10 pounds 12.48 ounces.  Average Fruits per Plant = 4 (4.43 exactly).  Note:  Because of their size, winter squash and pumpkins are not measured in bushels.

Estimated Carrying Capacity:     A 1-acre polyculture of maize, beans, and squash with hills spaced 4 feet apart feeds 1 family (4 people) for 1 year = 2.05 pounds of corn meal per person per day + 0.3567 pound (5.7 ounces) of dried beans for each person daily + 4.99 pounds of fresh winter squash per person daily.  This is more than sufficient to support a small family, especially if rations are supplemented by hunting and gathering.

Experimental Data (Maize):     Yields are recorded in pounds of clean, air dried corn per 1/4 acre.  All numbers are rounded down to the nearest whole pound.  Hills are spaced 4 x 4 feet equidistantly.  26 rows x 26 hills within each row = 676 hills x 4 corn plants per hill = 2,704 corn plants per 1/4 acre.

Year                    Maize Yield in Pounds per 1/4 Acre

2007                    463

2008                    895

2009                    590

2010                    848

2011                    556

2012                    990

2013                    934

2014                    804

2015                    689

2016                    727

10-Year Total Yield          7,496 pounds

Average Yield                   749.6 pounds per 1/4 acre

Yield Range                      463 to 990 pounds per 1/4 acre

Average Yield per Plant = 0.2772 pound = 4.43 ounces

Experimental Data (Pole Beans):     Yields are recorded in pounds of clean, air dried beans per 1/4 acre.  All numbers are rounded down to the nearest whole pound.  Hills are spaced 4 x 4 feet, equidistantly.  26 rows x 26 hills within each row = 676 hills x 4 bean plants per hill = 2,704 bean plants per 1/4 acre.

Year                    Bean Yield in Pounds per 1/4 Acre

2007                    103

2008                    146

2009                    92

2010                    132

2011                    84

2012                    161

2013                    124

2014                    172

2015                    128

2016                    160

10-Year Total Yield          1,302 pounds

Average Yield                   130.2 pounds per 1/4 acre

Yield Range                       84 to 172 pounds per 1/4 acre

Average Yield per Plant = 0.048 pound = 0.768 ounce.

Experimental Data (Winter Squash):     Yields are recorded in pounds of fresh fruit per 1/4 acre.  All numbers are rounded down to the nearest whole pound.  Squash plants are spaced every other row and every other hill within alternate rows = 13 rows x 13 hills within each row = 8 x 8 feet apart = 169 plants per 1/4 acre.

Year                    Squash Yield in Pounds per 1/4 Acre

2007                    1,353

2008                    2,138

2009                    2,025

2010                    1,497

2011                    1,446

2012                    2,140

2013                    2,040

2014                    1,669

2015                    2,194

2016                    1,732

10-Year Total Yield          18,234 pounds

Average Yield                   1,823.4 pounds per 1/4 acre

Yield Range                      1,353 to 2,194 pounds per 1/4 acre

Average Fruits per 1/4 Acre = 750

Average Fruit Weight = 2.43 pounds = 2 pounds 6.88 ounces

Average Yield per Plant = 10.78 pounds = 10 pounds 12.48 ounces

Average Fruits per Plant = 4 (4.43 exactly)

Commentary:     Traditional polycultures of corn, beans and squash are not commercially practical because planting and harvest cannot be mechanized.  Fish meal fertilizer is also un-economic because it costs more ($0.72 per pound) than most chemical or organic plant foods.  Planting nitrogen-fixing cover crops and sowing seeds in rows is far less expensive than traditional hill cultivation.

Strip cropping combines the ecological advantages of polycultures with the economic efficiency of farm machinery.  Plant narrow strips of cash crops following land contours.  (Adjust strip width to fit farm equipment).  Seed or transplant unrelated crops on adjacent strips to take advantage of edge effects.  Planting multiple species on each field increases biodiversity and greatly reduces crop pests.

Related Publications:     No-Till Hungarian Stock Squash; 2012 Tomato and Sweet Potato Polyculture Trial; and The Edge Effect.

Other Articles of Interest:     “Can Sunnhemp Outgrow Morning Glory?”; Worm Farming; Managing Weeds as Cover Crops; Weed Seed Meal Fertilizer; Trash Farming; Earthworm Primer; Planting Maize with Living Mulches; Living Mulches for Weed Control; Upside Down Potatoes; and Crops Among the Weeds.

Would You Like To Know More?     Please contact the Author directly if you have any questions or need additional information about modern or traditional polycultures.  Please visit:     http://www.worldagriculturesolutions.com  — or —  send an e-mail to:  http://www.worldagriculturesolutions@gmail.com  — or —  send a letter to:  Eric Koperek, Editor, World Agriculture Solutions, 413 Cedar Drive, Moon Township, Pennsylvania, 15108 United States of America.

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).

 

 

PLANTING MAIZE WITH LIVING MULCHES

What Is It?     Living mulches are cover crops grown to control weeds without herbicides or mechanical cultivation.  Seeds or transplants are set through the living mulch using no-till equipment.  Alternatively, fields can be planted by hand.  The best living mulches are low-growing nitrogen fixing legumes like Dutch White Clover (Trifolium repens).  Tall-growing legumes like Lucerne = Alfalfa (Medicago sativa) or Biennial Yellow Sweet Clover (Meliotus officinalis) also make good living mulches if managed carefully.

I’ve been working with Red Clover (Trifolium pratense) the past 40 years because the seed is less expensive than Dutch White Clover (Trifolium repens).  Sweet corn, popcorn, flint corn, flour corn, pod corn, dent corn, and oil corns all grow well when planted with standard red clover or medium red clover.

How To Do It:     Any type of maize can be top seeded = over seeded with red clover at the last cultivation.  The corn plants are tall enough (about 2 feet high) so that competition with the living mulch is minimal.

Rule-Of-Thumb:     Top seed = over seed maize with tall varieties of clover when corn plants have 4 to 8 leaves = 18 to 24 inches tall.  Maize should be 12 inches high before over seeding with Crimson Clover (Trifolium incarnatum), Sub Clover (Trifolium subterraneum), Dutch White Clover (Trifolium repens) or other types of low growing legumes.

Mow Low & Keep On Mowing:     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.

Feed & Water Liberally:     Corn 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.

Always remember that 2 crops are growing on the same field at the same time:  The mulch crop and the cash crop.  Careful management is required or both crops may fail.  Fertilize and irrigate generously to reduce competition between crops.

Sweet Corn Yields:     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 ~ 21,000 (17% field loss rate is common).  1 sack = 52 ears = 4 baker’s dozen.  1 baker’s dozen = 13 ears.  415 sacks = 1,660 baker’s dozen = 21,580 marketable ears per acre.  Note:  Yield figures are discounted 50% for typical losses to crows, deer, groundhogs, coons, ear worms, under size or poorly pollinated ears, and other causes.

Critter Control:     Raccoons (Procyon lotor) are a big problem in my area; unprotected fields are ravaged.  It is not uncommon to have 50 coons in a field of sweet corn each night.  To control coons, I use battery powered radios set to all-talk stations.  Move the radios to a different location every day.  As a last resort, dissolve 1 level teaspoon = 5 milliliters of Blue Streak Fly Bait in 1 can of regular Coca Cola and pour contents into a shallow bowl.  Set bait dishes along field boundaries to intercept coons before they get into the corn.  Note:  Blue Streak is a powerful poison that will kill any animal that ingests it.  Make sure to tie up your farm dogs to keep them safe.

Ideally, sweet corn fields should be protected with deer fencing.  If this is not practical, enclose fields with a low barrier just high enough to contain hounds.  Each field needs at least 4 deer hounds or similar large breed for adequate security.  Small breeds or lone dogs are likely to get mobbed by browsing deer that travel in herds of 40 or more animals.

Mulch-In-Place:     Buying and spreading mulch is too expensive for field scale agriculture.  It is far less costly to grow a mulch crop on the field needing weed control.  When mature, the mulch crop is killed by roller-crimping or mowing with a sickle-bar mower.  No-till equipment is then used to set seeds or transplants directly through the dead surface mulch.  Dutch White Clover (Trifolium repens) or other low growing legumes can be over seeded at the same time cash crops are planted.  Small clover seeds fill any gaps in the mulch aiding weed control and increasing field biodiversity.

Most mulch-in-place crops are cereals because grass plants decompose more slowly than broad leaf species.  4 to 5 tons = 8,000 to 10,000 pounds of long straw per acre are needed to provide 90% weed control in field crops.  Sow Common Cereal Rye = Winter Rye (Secale cereale) at 3 bushels per acre.  Roller-crimp or sickle bar mow when rye reaches 6 feet high or when seeds reach the soft dough stage.  Transplant or seed cash crop immediately.  Rye mulch provides effective weed control for 6 to 8 weeks; this is sufficient time for crop to establish and start to close the leaf canopy over the field.  Once crop canopy closes any weeds in the field will be shaded and minimally competitive.

Weed Farming:     It is possible to grow maize in weeds although this requires careful management.  Select a field with dense, luxuriant weed growth at least 3 feet tall (5 or 6 feet high is better).  Broadcast Dutch White Clover (Trifolium repens) or other low-growing legume into standing weeds.  Kill weeds with a sickle bar mower or flatten with a roller-crimper.  Seed maize with a no-till planter when the soil is warm = at least 65 degrees Fahrenheit.  Irrigate immediately or wait for rain.  You are now in a race against time.  Watch field diligently for corn germination and weed density.

It may be necessary to mow field 2 weeks after seeding if surface mulch is not thick enough to suppress weed growth.  Mow field as close to the soil surface as practical.  If weeds regrow quickly, mow field again 2 weeks later.  Adjust mower height to prevent killing corn seedlings.

The trick here is to germinate the corn as fast as possible — which is why irrigation is so profitable.  If maize seedlings have a few days head start over the weeds they will make a good crop.

The secret to weed farming is to manage wild plants just like any other mixed species cover crop.  Fertilize and irrigate weedy fields to encourage maximum growth.  More biomass (leaves & stems) = more mulch and better weed control.

Maize Polycultures:     Planting corn, beans, and squash together in the same field is rarely practiced nowadays because interseeding is difficult to mechanize successfully.  Consequently, most traditional polycultures are seeded by hand.

Space maize widely so beans and squash get enough light to make a crop.  40 inches between rows and 12 inches between plants within each row is traditional practice = 62 rows x 208 plants per row = 12,896 plants per acre ~ 3.3 square feet per corn plant.

Use a lawn mower to clip living mulch before seeding beans and squash.  Alternatively, wait until the last cultivation (when corn plants are 2 feet tall) then over seed field with Dutch White Clover (Trifolium repens) directly beans and squash are planted.

Wait until soil temperatures reach at least 65 degrees Fahrenheit and corn plants have 8 leaves ~ 24 inches high before planting pole beans and squash.  Earlier plantings are rarely successful because beans and squash overrun short maize stalks.  Soak bean and squash seeds in warm water overnight to speed germination.  Plant 2 or 3 beans close to each corn stalk.  Thin later to 1 strong seedling per maize plant = 12,896 pole bean plants per acre.  Seed squash every other corn row and 6 feet between plants within row = 31 rows per acre x 34 plants per row = 1,054 squash plants per acre.  Irrigate immediately beans and squash are planted.

Strip Cropping:     Strip cropping combines the pest control advantages of polycultures with the efficiency of modern farm machinery.  The idea is to divide farms or fields into long, narrow strips 4 to 16 rows wide depending on the crop and available machinery.  Like ribbons each strip wends its way across the countryside following land contours.  Strips on either side are planted with unrelated crops.  Long fields are good for mechanical efficiency (fewer turns) while narrow fields maximize biological edge effects (fewer pests).

For example, instead of growing corn, soybeans, sunflowers and alfalfa in separate fields plant each crop in narrow strips:  4 rows of corn + 4 rows of soybeans + 4 rows of sunflowers + 4 rows of alfalfa.  (Try to make each strip about the same width).  Repeat this pattern across the field or over the entire farm.  Note how tall and short crops are alternated for better light penetration.  Legumes are paired with non-legumes.  Each crop is unrelated to its neighbors.

Growing different row crops close together mimics the biological diversity of companion planted gardens and traditional polycultures.  Translation:  Insect pests go somewhere else for lunch.

Build-A-Toy:     No-till equipment is costly.  If you are mechanically minded you can build an inexpensive no-till seeder in your own garage.  At minimum, you need 5 things:  (1)  A large (20 inches or more in diameter) coulter with a razor sharp edge to cut through standing vegetation.  You can use a fluted coulter at your discretion.  (2)  Adjustable depth 3/4 inch or wider blade to open a slot for seeding.  A fertilizer knife, cultivator shovel, or chisel tine can be used for this application.  (3)  A delivery tube to drop seed into opened soil.  Tube can be any convenient dimension (up to 3 or 4 inches diameter to plant potatoes or set transplants).  (4)  Double press wheels to ensure good seed-to-soil contact.  (5)  Removable iron weights to adjust planter mass so coulter cuts through surface trash and seeding knife penetrates the soil.  Other items can be added to the basic rig as needful.  For example, add a seat then a child can manually drop seeds, potatoes, or transplants.

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

Would You Like To Know More?     Please contact the Author directly if you have any questions or need additional information about growing maize in living mulches.

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).

 

 

 

 

 

 

 

 

 

 

 

 

 

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).