Producers contemplate switching to soybeans
Forecasters are calling for a high pressure system to move into our area later this week-end and dry things out. I agree with all of you, it is much overdue. I really can’t remember a spring like this. Hopefully the improving condition will stay with us well into next week or two and we can get most of the planting done. The outlook for May 30-June 5 calls for near normal rainfall and temperatures 3–5 degrees above normal. It has been a really tough spring. After we all make it through, and when the next wet spring comes along, we can all look forward to saying, “Yes, its wet but it’s not even close to the spring of 2011.”
As we get later in May, a lot of producers are contemplating switching to soybeans because of the late date in planting. When considering what to do next, Anne Dorrance, OSU Extension Specialist, Plant Pathology, suggests these factors to consider:
- For fields that have been continuous corn — target these first. The year of soybeans will be great to help give a break to those pathogens that are residue borne. It will give that corn residue a chance to break down before adding to it. This is especially important if there has been gray leaf spot, anthracnose or northern corn leaf spot in the field.
- For fields that were in soybeans in 2009–2010: Continuous soybeans leads up to a build-up of both soil borne and residue borne plant pathogens. The worst culprits are soybean cyst nematode and frogeye leaf spot. In Ohio, both of these pathogens have contributed to significant yield losses when susceptible varieties were planted in the same field year after year. Soybean cyst nematode is best managed with crop rotation — primarily a non-host crop such as wheat or corn. Frogeye leaf spot is managed with resistant varieties — and avoiding planting soybeans in fields that had frogeye the year before. For those fields where you had been planting soybeans and were switching to corn — avoid switching fields where SCN has reached high numbers. It is important to keep the rotation scheme in place.
- Check the resistance of the variety. The primary concern here is for Phytophthora root and stem rot. Not all varieties sold have high levels of partial resistance (tolerance) and unfortunately, these wet saturated soil condition have the pathogen “primed” for when soybeans are in the ground. For Ohio, varieties with Rps1c, or Rps1k, or Rps3 or Rps6 PLUS high levels of partial resistance are required for optimum stand throughout the growing season.
- Treat the seed. Soybeans planted into soils that have been saturated need a seed treatment. There are a plethora of seedling pathogens in Ohio’s poorly drained fields and they need a seed treatment. Target products that will manage both the true fungi and the water molds.
- From a soil fertility standpoint, switching to soybeans does not represent much of a change in your fertility program. Anything you did last fall in preparation for this year’s corn will be to the benefit of your soybeans. If you are breaking a continuous corn system with soybeans (while this may seem a bit early), plan on taking a nitrogen credit next year when you come back to corn. For those who did apply anhydrous ammonia earlier this spring, soybeans will be nitrogen scavengers in a nitrogen rich environment, so those applications will not adversely impact your soybeans this summer.
Rob Leeds is an OSU Extension Educator for Agriculture/NR.