AMES, Iowa -- Like everyone affected by the June floods, Iowa’s organic producers are busy sorting priorities and positioning themselves to deal with what has been revealed by the receding waters, according to Kathleen Delate, Iowa State University Extension organic crops specialist. With the range of situations from operation to operation, all producers will be considering the short, mid-and long-term consequences of the floods of 2008, Delate said.
Changing Your Rotation: Obtaining a Temporary Variance
By now, the viability and potential profitability of the crop initially planted has been determined and decisions have been made whether to replant the same crop, plant another crop, or not plant at all, Delate said. The USDA-National Organic Program requires that farmers rotate their crops; e.g., corn following corn is not permitted. Fortunately, at least for this crop year, organic certifiers will not enforce filed farm-plan crop rotations in the 83 counties declared disaster areas by Iowa Governor Chet Culver.
According to an e-mail letter from National Organic Program Acting Director Barbara Robinson to Iowa’s Secretary of Agriculture Bill Northey, to be eligible for the temporary variance a producer must be farming in a county declared a disaster area and clearly document that the crop planting was “actually delayed in planting due to heavy rains and flooding.” You may obtain your variance by calling the Iowa Dept. of Agriculture and Land Stewardship organic program at (515) 281-5783 and requesting the form you need to fill out for the variance.
Soybeans
The most likely cash grain crop to be planted at this late date is soybeans and the primary questions are seed availability and whether the maturity should be shortened, Delate said. In a recent article summarizing retired ISU Professor Keith Whigham’s soybean maturity studies conducted after the 1993 floods, ISU Assistant Professor Palle Pedersen concluded, “Based on that data, the yield potential from planting in mid-June was approximately 60 percent of the optimum yield in northern and central Iowa and 80 percent of the optimum yield in southern Iowa. When planting was delayed until early July, soybean yield potential dropped even further and producers would have approximately 33 percent of the maximum yield in northern Iowa and 50% in central and southern Iowa available. Producers should plant their original soybean variety unless planting is delayed beyond late June in northern and central Iowa and beyond early July in southern Iowa.”
Pedersen’s final conclusion was that “Growers in central and northern Iowa may switch to a shorter maturity group and shorten the maturity group by 0.5 to 1.0. Southern Iowa growers can wait another 10 days before needing to switch to a shorter maturity group. No data supports planting soybeans as a grain crop after mid-July in Iowa.”
Corn
While soybeans can provide some level of yield, corn presents a riskier proposition. The issue here is frost. Roger Elmore, professor of Agronomy at ISU, examined a 1990 planting date study conducted by ISU Extension corn agronomist Garren Benson who found that producers could expect about a 33 percent to 66 percent loss from maximum yield from corn planted July 1-10, regardless of whether an earlier maturing variety was substituted, depending on the first killing frost. However, as with conventional producers, fertility will be a major consideration.
Forages and cover crops
Planting forages and cover crops is another opportunity to be considered either for on-farm use or for market. Covering the soil with a crop is mandatory in organic production. Stephen Barnhart, forage specialist in ISU’s Agronomy Department, provides a relatively wide range of forage and cover crop options for producers who have determined that they will not be able to replant or substitute a cash grain crop. Included are foxtail millet, Japanese millet, sudangrass, sorghum x sudan hybrid, hybrid pearl millet and oats, all of which can be planted now until mid-July, except oats, which can be planted as late as mid-August. Besides providing a crop that can be sold into a premium market, planting forages and cover crops will help to mitigate the damage done by floodwaters and heavy rains.
Pest Pressures
While disease pressure was expected to increase based on high humidity, to date, no spray recommendations have been put forward based on the level of disease observed in organic corn and soybeans, Delate said. There is an extensive soybean rust monitoring system in place throughout the region, so any considerations on the need to spray for this disease will be announced if it spreads to Iowa.
Bean leaf beetles have been observed at low levels in organic soybeans, but spray recommendations are unnecessary at this time. Weeds are the main concern for late planted or replanted fields. Many organic farmers missed rotary hoeings due to wet soils and are now facing extensive weed pressure in the row. Cultivation can help bury many weeds in the row, but additional “walking” for weeds will undoubtedly occur this year. Flaming is another option. Many organic farmers have included propane (LP) flame-burners as an additional tool in their weed management toolbox. Flaming is used particularly during times of high field moisture when tillage with large machinery is not feasible. In drier weather, flaming is used in conjunction with cultivation. Flame weeding of corn can be accomplished when corn is less than 2 inches in height or 8 inches to 1.5 feet in height.
Other growth stages are considered potentially damaging to the corn meristem (growing point). According to several Iowa farmers, soybeans can be flamed prior to emergence and at the 1- to 1.5-foot height stage. Caution must be used in flaming soybeans, however. Mixed results have been reported, including damaged soybeans and decreased yields. Because the growing terminal of corn is more protected within the whorl, corn can withstand greater damage from flaming, compared to soybeans with their exposed growing points. Several flame burners are commercially available, including complete units and individual burner kits that can be attached to tractor tool bars. Flamers are usually run at 38–40 psi with a tractor speed of 4 mph, but specific rates will be based on the crop stage, weed species present and the manufacturer’s recommendations.
Long-term Consequences
Delate said ISU will continue to disseminate information on the long-term effects from the floods as the season progresses. Scientists at ISU are constructing simulations predicting different outcomes based on when the crop was planted and how the market will behave. There is general agreement that the price of organic crops, and subsequent food prices, will continue to rise. How this will affect the future of organic meat production is currently an area of grave concern. The bottom line is that demand for organic products continues to rise, and Iowa organic farmers are needed to help fill that demand. For additional information and postings, please visit the ISU Organic Ag Program webpage at http://extension.agron.iastate.edu/organicag or contact Kathleen Delate at (515) 294-7069, kdelate@iastate.edu
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