“Can Sunnhemp Outgrow Morning Glory?”

I get the most interesting questions on my website.  Some provoke editorial response:

Biological agriculture is a race between crops and weeds.  The farmer’s job is to give his crops an unfair advantage in competition for sunlight.  One way is growing cover crops to smother invasive weeds.  Sunnhemp (Crotalaria juncea) is an effective mulch crop for weed suppression.

Wild Morning Glory (Ipomoea species) is the bane of my existence.  Closely related to sweet potatoes, morning glories thrive in poor soils, are immune to most insects, and grow so rapidly that they overwhelm all surrounding plants.

In Butler County (30 miles north of Pittsburgh, Pennsylvania) morning glories are like intermittent epidemics.  Some years you rarely see a vine.  Other seasons your fields are covered.

I returned from a business trip to find my neighbor’s back-40 strangled by herbicide resistant morning glories.  Vines blanketed the land like Kudzu (Pueraria montana).  He sprayed tankfuls of glyphosate trying to save his soybeans.  All that did was make the weeds mad.   6 weeks later, vengeful vines obliterated his GMO corn.

My neighbor was hitching up his 8-bottom moldboard when I offered to help.  George has a dim view of “organic farming” but he likes spending money even less, so it was not a difficult decision:  Plow everything under or let Eric make a fool of himself.  Hmm. . .

My solution:  60 pounds per acre of rotary seeded Sunnhemp followed by a 30-year-old sickle-bar mower.  Sow-And-Mow eliminated his weed problem.  The Sunnhemp reached 8 feet high in 7 weeks, shading all competing vegetation.

Next, I broadcast 12 pounds per acre of Dutch White Clover (Trifolium repens) into the standing cover crop then mowed the Sunnhemp with a bush hog.

In Autumn I no-till drilled 60 pounds per acre of pelleted Winter Rye (Secale cereale) into the mature clover.  The field required no other work until grain harvest the following summer.

There is a lesson to be learned here:

RULE:     Always seed cover crops at maximum rates for weed control.

RULE:     Do not plow, disk, or harrow — this only encourages weed germination.

RULE:     Keep fields covered with growing crops at all times to kill weed seedlings.

Follow these rules and weeds will NEVER get established in your fields.

This is what Biological Agriculture is all about:  Crop competition keeps weeds controlled without need for mechanical cultivation or chemical herbicides.  Let nature do the heavy lifting.

Related Publications Include:     Managing Weeds as Cover Crops; Trash Farming; Planting Maize with Living Mulches; Living Mulches for Weed Control; and Crops Among the Weeds.

Other Articles of Interest:     Weed Seed Meal Fertilizer; Organic Herbicides; Pelleted Seed Primer; and Forage Maize for Soil Improvement.

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

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

 

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2012 ORGANIC CABBAGE TRIAL

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

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

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

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

Soil Type:  Everglades Peat = Muck

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Agronomy Notes:

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

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

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

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

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

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

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

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

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

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).