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: The Twelve Apostles; 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 = firstname.lastname@example.org
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).