A Seminar at Cornell University, Monday 19 November 2018. Sponsor: Norman Uphoff, Professor Emeritus, International Programs SRI Project, College of Agriculture and Life Sciences. Guest Speaker: Eric Koperek = Website:

My ancestors were literally dirt poor = without soil. They farmed abandoned quarry land. Over the course of 8 centuries they created 10 to 15 feet of topsoil = 1/5 to 1/4 inch yearly. This is how they did it:


Copy Nature: “Gardeners are the best farmers”. Observe nature closely then mimic what you see. How do you grow your garden? What do you see in the forest? Copy this in your fields. The idea is to combine biological processes with labor efficient agricultural machinery.

Keep Fields Green: Fields should be covered with growing plants 365 days yearly. Do not waste sunlight. The goal is to produce the maximum possible amount of organic matter per square foot each year. More plants = more organic matter = increased populations of soil “critters” = faster nutrient cycling = higher crop yields. “Roots in the ground all year round”.

No Soil Disturbance: Avoid plowing, disking, harrowing, and cultivation whenever practical. Transplant crops or surface sow using pelleted seed and no-till equipment. Tillage kills earthworms and destroys fungal networks = lower crop yields. “Good farmers grow fungi. The fungi grow the crops”.

Keep Soil Covered: Use living mulches, dead mulches, or growing crops to keep fields covered year-round. Control weeds with Mulch-In-Place. Never leave soil bare not even for a single day. Harvest and replant fields the same day or try relay planting: Sow the following crop several weeks before the first crop is harvested.

Worm Farming:  Use earthworms (Lumbricus terrestris) to till and fertilize fields. Earthworms are the key to biological soil management. Worms eat their weight in soil and organic matter daily. One million earthworms per acre = 1 ton of worm manure daily. More worms = more nutrients = higher crop yields. “Feed the worms and the worms will tend your crops”.

Increase Biological Diversity: Grow many crops rather than one crop. Plant polycultures whenever practical. Multiple crops diminish risk of crop failure. “Life breeds life”. More crops = more biological activity = higher yields.

Watershed Management: Agriculture is all about water management. Mind the water and everything else will fall in place. The goal is zero runoff = trap every drop of rain and flake of snow that falls on the land. Store water for dry seasons. Build ponds wherever possible. Irrigate whenever practical. Water is the best investment a farmer can make. One drought pays for an irrigation system.

Biological Nitrogen Fixation: Grow your own fertilizer. Rotate nitrogen fixing cover crops with cash crops. Plant small grains and clover together. Seed maize into roller-crimped Red Clover (Trifolium pratense). Transplant vegetables into Dutch White Clover (Trifolium repens). Topseed cash crops with low growing legumes. Include 50% legumes in pasture and cover crop mixes.

Increase Edge Effects: Divide big fields into smaller fields. Plant hedgerows and windbreaks. Mix fields with pastures, orchards, hay fields and forest. Grow unrelated crops in narrow strips = strip cropping. Plant borders and head rows with clover and insectary crops. The idea is to attract and maintain large populations of beneficial insects. “The good bugs eat the bad bugs”.

Plant Multi-Species Cover Crops: Mixtures of plants repel insect pests, fix more nitrogen, better resist drought, and produce more organic matter than plants grown alone. Plants in mixtures cooperate with each other sharing water and nutrients through fungal networks. Multi-species cover crops can fix more than 100 pounds of nitrogen per acre; this nitrogen is not accounted by conventional soil tests. Mixed species cover crops promote maximum earthworm populations, up to 8 million worms (8 tons) per acre = 184 worms per cubic foot of topsoil.

Long Rotations Increase Yields: 7-year rotations best control soil diseases and insect pests. Never follow similar crops in sequence (oats & wheat; carrots & potatoes; lettuce & spinach). Never follow crops in the same botanical family (tomatoes & peppers; pumpkins & squash). Never follow plants sharing common pests or diseases.

Grass Crops Make Deep Soils: Integrate perennial grass crops into field rotations. This is called Ley Farming. Perennial pastures and grazing animals promote large earthworm populations = 1 ton per acre = 1 million worms per acre = 23 worms per cubic foot of topsoil = 120 miles of earthworm burrows per acre. Worms produce vast amounts of castings = manure, more than needed for any commercial crop.

Integrate Animals and Crops: Use grazing animals to fertilize fields. Practice Rotational Grazing, Mob Grazing, Stomp Seeding, Cattle Penning, and Folding = Yarding to improve fields and increase yields. Sustainable agriculture is difficult to achieve without farm animals.

Plant Weeds and Crops Together: Reserve 5% to 10% of farm for native weeds. Plant weeds in narrow strips within and around fields. Grow orchards and vine crops in weeds. Weeds provide food, shelter, and alternate hosts for beneficial insects that protect cash crops. “Weeds are the shepherds of the garden”. More weeds = less insect pests.

Plant Flowers with Crops: Most beneficial insects have small mouth parts and so they need tiny flowers on which to feed. Healthy farms grow many small-flowered plants to encourage maximum populations of helpful insects. For best results plant flowers and weeds next to crops needing protection. Sow flowers around fields, orchards, vineyards — anywhere there is open space. More flowers = less pests.

Making Sense of It All

Biological agriculture requires patience. Converting a field from conventional chemical agriculture usually requires 12 to 15 years before the soil is healthy enough to sustain commercial yields without added fertilizer.

Active biological soils easily produce 160 bushels (8,960 pounds) of maize per acre without plowing, fertilizer, herbicides, or cultivation. Irrigated fields can exceed 200 bushels (11,200 pounds) per acre.

On biologically managed soils, most Japonica rice varieties yield 3.5 ounces of grain per plant = 9,528 pounds per acre when plants are direct seeded 12 inches equidistantly on drip irrigated fields. (Indica rice varieties yield less, about 1.5 ounces of grain per plant = 4,083 pounds per acre).

Related Publications: Polyculture Primer; Strip Cropping Primer; Worm Farming; Managing Weeds as Cover Crops; Intensive Rice Culture Primer; Weed Seed Meal Fertilizer; Earthworm Primer; Planting Maize with Living Mulches; Living Mulches for Weed Control; Crops Among the Weeds; Forage Maize for Soil Improvement; Forage Radish Primer; The Edge Effect; Coppicing Primer; and Rototiller Primer.

Would You Like To Know More? Please contact the Author directly if you have any questions or need more information about Biological Agriculture.

Eric Koperek. Office Address: 413 Cedar Drive, Moon Township, Pennsylvania, 15108 United States of America. Cellular Telephone Number: 412-888-7684. E-Mail Address: Website Address:

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).



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:  — 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:

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).