Thinking of double-crop soybeans after wheat?
By Kent Wolfe, CCA-ON, 4R NMS
Crop Sales Specialist,
AGRIS Co-operative - Dutton
Over the last couple of weeks, I have had more enquiries about trying some double-crop soybeans after the wheat is harvested than I can remember in quite a few years. Typically my response would be that we need to step back and think about why we are growing the wheat in the first place; which normally is to improve the rotation that leads to increased yields in corn and soybeans, improve soil health and structure and also gives us a great opportunity to seed some summer cover crops. But, the reality of soybeans for fall harvest being north of $15 per bushel certainly changes the conversation. Research over the last few years by various groups here in Ontario have found there are some management tips that will help mitigate some of the risks and help make it less risky.
It all starts with harvesting the wheat as early as possible. Maximum yield potential has been found to be when the soybeans are planted around the first of July. Every day we plant after that costs about a bushel per day so in all reality, we should be probably looking at the 15th as the cut-off date for the majority of our trade area, for the deep southwest branches in Essex county the cut-off date probably could be pushed back to the 20th. Clip the wheat as close to the ground as possible and bale the straw, this will minimize the amount of residue and help to avoid hair pinning when we seed. I like no-till seeding to maintain soil moisture which is another important factor to look at. If the soil has large cracks and there is no moisture to plant into within two inches, the likelihood of getting the soybeans up quick diminishes very quickly.
Variety selection in terms of maturity and plant characteristics also needs to be considered. When picking a variety maturity is should be dropped back by .5 to .7 based on maturity group rating, if your normal maturity soybean is a 2.2 (3125 CHU) chose a 1.5 (2950 CHU) to 1.7 (3000 CHU). I like to look for a variety that has a tall height and is branchy. These plant characteristics will help maximize the number of nodes that will be produced and give the most yield potential.
The seeding rate and row width is also very important. Solid seeded or as narrow of a row width as possible will maximize canopy ground cover, this not only helps with weed control but also maximizes sunlight interception by the plant fueling the photosynthesis process in the plant. Seeding populations of 225,000 to 300,000 seeds per acre are needed. Start at the lower end at the beginning of the timeframe and increase as you move towards the middle of July. Table 1 below shows the yield advantage at different seeding rates from a trial conducted by the OMAFRA crops team in 2012 at Bornholm, this plot was planted on the eleventh of July.
Table 1. Double crop yield for various seeding rates (2012, Bornholm)
While double-crop soybeans does carry a lot of risks with zero guarantees, the current market prices do support the idea of considering it and maybe taking the chance.
If you have questions or want to discuss further, contact your local AGRIS Co-op location or crop sales specialist to have a plan in place and be ready to implement if conditions are favourable.