Growing Organic Soybeans on CRP Land

Kathleen Delate, Iowa State University

Determining Your Market

            One of the first issues to address is your market. The majority of organic soybeans are going to Japan for use in the “tofu” market, although organic soybeans are also used for tofu and other soy products in the U.S. Edible soybeans are clear-hilum beans (no black mark on the seed). In the IDALS booklet, you will find a list of buyers for organic grains. Check with them first to determine the market prices you can contract with them for the 1998 growing season [contracts based on acreage (regardless of yields) vs. bushels are best; you don’t always know what you’re going to get your first years]. Organic production generally increases as the farm progresses to a more organic situation (improved soil health and balanced insect populations). Average organic soybean yields this year ranged from 25 bu/A to 53 bu/A on the best farms. Prices received in 1999 ranged from $20/bu to $12/bu (see variety selection below) for certified organic beans.


Certified Organic

            In order to sell your crop as certified organic, you must be certified by one of the certifying agencies listed on the Organic Information Fact Sheet. Each certifying agency has its own rules, but in general, they will require the following:

·        No synthetic fertilizers for three years

·        No synthetic pesticides (fungicides, insecticides, herbicides) for three years

·        Crop rotations (at least three out of four years); necessary for breaking up weed, insect and disease cycles and maintaining soil fertility

·        No synthetic hormones or antibiotics for livestock; organic feeds and pastures required.

            Soil fertility in organic systems is maintained through crop rotations (usually soybeans-corn-oats-alfalfa or some variation of this system), applications of manure (manure from non-organic farms must be composted for 6 weeks before application or applied 3 months prior to crop harvest), and/or applications of seaweed, fish emulsion or plant/animal-based products, such as feathermeal. Soybeans add nitrogen to the soil and can be grown without fertilizer in their first year. Subsequent crops must include rotations of grain crops (ideally with nitrogen-adding cover crops) in order to maintain adequate fertility for future soybean crops.


Land Preparation

            CRP land must be adequately prepared for organic soybean production. Grasses in the CRP land must be DEAD before planting beans. In order to assure this, one should plow (mold-board plow) in the fall and plant a cover crop of winter rye to help with erosion, weed control (the rye serves as a repellent to many weeds) and provide some organic matter when turned under in the spring.

            If planting is not feasible past October, you should still plow to help break up the soil and kill the grasses. It may take 2 to 4 tillage operations to break up the soil and kill the grasses before planting. The ground should be relatively smooth and friable before planting to allow for good seed-to-soil contact. Planting populations (rates/A) will depend on the soybean variety planted, but in general, planting populations are high to provide quicker, in-row shading and weed management. Again, check with your market: some buyers require large beans (e.g., Vintons), others prefer smaller sizes (e.g., Pioneer 9305 or ISU varieties).

            Take a soil sample (sample in at least four places per acre) to determine if lime is needed for adjusting your pH. Your local county Extension office can help you with soil sample information and where to send the sample.


Planting and Weed Management

            Field cultivators will kill most rye cover crops at the 6 to 8 inch stage, with scratchers dragging behind to bring residue to the surface. If needed, taller rye can be cut with a stalk chopper first. After waiting about a week for the disturbed weed seeds to germinate, a second field cultivation will kill the remaining rye crop. Plant soybean seed at least 1 inch deep when the ground has sufficiently warmed. Some organic farmers believe that adequate ground temperature is critical, and did not plant their soybean crop until June this year. Weed control is the most critical element of organic soybean production. Tillage operations are both an art and science. You should rotary-hoe weeds (in the white-root stage) 3 to 5 days after planting at a slow speed (5 mph) for good penetration; at 7 to 10 days (once beans have emerged), hoe again a little faster (7-9 mph) to enhance surface aggressiveness. You should check the hoe’s penetration, weed kill and crop response to determine optimal speed and depth. Cultivate as quickly as possible at a slow speed the first time. In mid-growing season (when plants are flowering), cultivate again at a faster speed (to throw about 1 inch of soil up around plants). The last cultivation should again be slow (5 mph). Cultivator additions which help many organic farmers include guidance mirrors, disk hillers, metal tent shields, and sweep configurations (e.g., “26-inch one-piece sweeps in 36-inch row spacings”). Details on cultivators and recommended tillage operations can be found in the book, “Steel in the Field” by the USDA Sustainable Agriculture Network (available through ISU for $17).


Harvesting and Subsequent Crops

            The harvesting, cleaning and storing of certified organic soybeans is specified by your certification agency.  All certified organic beans must be separated from conventional beans, so combines, cleaners and bins must be cleaned between conventional and organic harvests (particularly important if hiring operators/machines). Storage bins must be free of other products and used only for organic beans. It is best to purchase a separate storage bin for your organic beans. With clear-hilum soybeans, clean beans, free of discoloring soil and/or weed seeds, are more important than with soybeans used for feed. An easy technique is to wait until weeds are dead before combining. There are various methods to keep soybeans as clean as possible during harvest (e.g. combines with dual rotating screens, “dirt guards,” smooth plates to prevent soil contamination, etc.). Cleaner beans equal higher prices from buyers. Buyers usually require samples from each load supplied. Clean-out usually averages 10-15%. There is a market for cull beans (splits and small beans) so check with your buyer. There is also a market for “transitional” beans (crops in the three-year transition phase between conventional and organic).

            Because rye is not a good cover crop prior to corn, oats may selected instead. At leaf-yellowing, oats can be over-seeded into soybean fields. Freezing weather kills the oats, but stalks remain on the surface to protect the soil from spring erosion. Organic corn currently is priced at a 100% premium over conventional corn, but with the new rules from the USDA Organic Agriculture Program arriving in 1998, the need for organic corn for livestock feed may escalate and drive prices even higher. Rotations will always be key in a properly functioning organic farm to help break up insect, weed and disease cycles, so you should always plan for subsequent crops to organic soybeans.