Nineteen ninety-seven was my first year to grow certified organic corn. To be certified, you have to have records to prove no chemical use for three years.
We compared the returns from the organic corn and a field of our conventionally raised corn (Table 10). The conventional corn was planted April 28th on second year corn ground following alfalfa, with a manure N credit of 30 lbs and alfalfa credit of 50 lbs N. The organic corn was planted May 20th on first-year ground following alfalfa and manure. Weed control was good in both fields. Stalk rot was a problem in both fields.
I do not think fertility was limiting on the organic field. Corn following alfalfa without fertilizer or manure has been my best corn field for years. Organic corn is normally planted later to aid weed control. The later planting date plus lack of heat units in northeast Iowa were a factor this year. Ceiba 3475 has done well on sod ground in the past, but it is too late (108 days) for May 20th planting in northeast Iowa. Next year we will plant 100-day corn.
Of course, corn production doesn’t tell the whole story of farm profitability. We may net more money on organic corn, but we won’t be growing it as often. My crop rotation will be a five-year one: small grains, alfalfa, corn, soybeans, corn. The crops that are less profitable than corn will still contribute to the overall operation of the farm.