Organic corn earns high grades in OSU field tests
Given the right conditions, organic farming can produce, on average, as much corn per acre in Ohio as conventional farming can, according to an Ohio State University study.
Corn hybrids grown in last year's Ohio State Organic Corn Performance Test produced 13 percent more corn per acre than the statewide average yield -- most of that conventional corn -- and topped the record-high state average yield by four bushels per acre.
One hybrid tested did even better, beating last year's state average corn yield by nearly 50 percent.
The results show "how well organic corn can perform under good management and weather conditions," said Deb Stinner, a scientist on the study and the head of Ohio State's Organic Food and Farming Education and Research (OFFER) program.
Until now, organic corn yields in Ohio "were thought to be considerably lower than conventional yields," Stinner said, though exceptions -- Ohio organic farms with consistently high corn yields -- have always existed.
Organic farming uses no synthetic pesticides or fertilizers, instead employing manure, compost and cover crops to feed the soil and the crops that grow in it. Cultural practices such as cultivation and crop rotation limit weeds and pests.
"A constellation of factors," including good weather, "good but not excessive" soil fertility and, especially, good weed control, led to the test's high yields, Stinner said.
The corn saw few problems from pests and diseases, added co-researcher Peter Thomison of Ohio State's Department of Horticulture and Crop Science.
The test took place on certified organic farmland in Wood and Wayne counties, both sites in northern Ohio and both managed by the university's Ohio Agricultural Research and Development Center (OARDC).
Alan Sundermeier of Ohio State University Extension's Wood County office and Rich Minyo and Allen Geyer, both of the Department of Horticulture and Crop Science, teamed with Stinner and Thomison on the study.
The test compared 23 organic corn hybrids. It measured yield and other key traits, such as stalk lodging, grain moisture content at harvest and the percentage of seeds emerging after planting. It did so at two different seeding rates -- 23,000 seeds per acre and 28,000 seeds per acre.
The plots grew at OARDC's West Badger Farm near Apple Creek and at the John E. Hirzel Sustainable Agriculture Research and Education Site near Bowling Green, run by OARDC and OSU Extension in partnership with the Agricultural Incubator Foundation.
The West Badger Farm averaged 171.4 bushels per acre and the Hirzel Site 153.6 bushels per acre, for a combined average yield of 162 bushels per acre.
Tops in the test: Doebler's N659, 212.2 bushels per acre, reached at West Badger at the lower seeding rate.
To compare, the Ohio Department of Agriculture estimated last year's statewide average corn yield at 143 bushels per acre, while countywide yields in Wood and Wayne counties averaged 171.8 bushels per acre and 146.1 bushels per acre, respectively.
The weather in 2005 helped organic corn several ways, Stinner said. It enabled growers to prepare a good, clean seed bed; allowed for timely planting -- typically later than for conventional corn -- and timely weed control -- five times by mechanical cultivation; and provided enough rain enough and at the right time to keep the corn developing well.
Especially important was the low weed pressure at the West Badger Farm, the result of five years of diligent management. A long-term war of attrition -- started in 1999 when certain fields at the farm began the transition to organic production -- reduced weed numbers and seed production, and drew down the weed seed bank in the soil. The work paid off in higher yields, Stinner said.
Other differences between the two sites included:
* West Badger got almost 31 inches of rain, Hirzel not quite 20 inches.
* West Badger corn followed red clover in the rotation, while the Hirzel corn followed alfalfa.
* West Badger plots received one ton of Daylay composted poultry manure; the Hirzel plots did not.
Though planted later than conventional corn, the plots at both sites were planted in time to avoid a major pest, the European corn borer, Thomison said.
Diseases, too, caused few problems because of crop rotation. Rotating corn with other crops means the corn gets planted in a fairly clean slate: the soil harbors less corn-disease inoculum.
Organic farming generally takes more work than conventional farming but pays better per unit for crop grown. At Detroit the week of March 1, for instance, a bushel of organic corn earned more than twice as much as a bushel of conventional corn, $5.50 versus $2.10, according to The New Farm's online Organic Price Index.
Organic farmers can't grow corn as often as conventional farmers can. They rotate with other crops. In a given field in a four-year span, an organic farmer might plant corn once, while a conventional farmer might plant twice or even every year.
But a recent Cornell University study says higher prices still make the net return per acre for organic corn equal to or greater than that of conventional corn.
The study, published in the July 2005 issue of the journal Bioscience, found organic corn and soybeans produce as much as their conventionally grown counterparts -- more under drought -- while requiring 30 percent less fossil energy, less water and no synthetic pesticides.
The Ohio State Organic Corn Performance Test continues this summer, part of a long-term OFFER effort to evaluate organic corn hybrids. Plans call for testing at other sites and over many years.
Complete test results are available from county offices of OSU Extension or online at http://agcrops.osu.edu/story.php?setissueID=119&storyID=678 .