Agronomy: What To Do When Switching Back to Soybeans

What you need to know when switching back to beans.

Commodity prices favor growing more soybeans, and this could mean more producers in Illinois will be growing more beans in 2015.

Planting continuous corn or a long corn and short soybean rotation has been common, and farmers have learned how to manage through the challenges of corn in the operation. However, with soybean prices possibly providing greater enterprise profitability, growers will be switching more acres to soybeans due to lower production costs and a greater relative price. However, it is still a year to keep a lid on production costs. But remember if you are planting soybeans for the first time after a few years in corn, you can plan on at least a 10% yield bump.

If you are switching to more soybeans consider some of the following actions to improve profitability:

• Variety selection is key. There can be a 10- to 15-bushel yield differential if you don’t select the best variety.
• Move to no-till to reduce production costs. Since you can plant later, soils should be warmer and drier and a higher seeding rate and soybeans’ compensatory nature are more forgiving. Forego tillage!
• Plant early into good soil conditions. Early planting means more nodes and potential pods. And more pods means more yield. One more pod with 2.5 seeds per pod gives two more bushels per acre.
• Reduce your seed rate to 120,000 to 140,000 per acre. Soybeans are very compensatory in nature and it has been demonstrated that 100,000 plants per acre at harvest maximizes yield.
• If you fertilized for two crops before the last corn crop, and soil test levels are in the medium to high range, you can forego application of dry fertilizer.
• If you apply foliar fungicides and insecticides as a routine plant health practice, adopt an integrated pest management approach and only apply what’s warranted based on scouting and pest thresholds.

If you are switching to soybeans after a few years in corn, consider the following:

• Inoculate your seed with rhizobia bacteria to make sure the plants form nodules and fix ample amounts of nitrogen this season.
• Check your soil pH to make sure it is greater than 6.2. Legumes are sensitive to acidity and bacteria will not fix nitrogen in acid soils.

Remember you have to protect plants to produce yield.

• Treat your seed so that as many seeds germinate and seedlings emerge as possible. You have to have a good stand with no empty spots to maximize yield.
• Run a herbicide program with a residual pre-emergence herbicide. You want to start clean and keep the field clean for 4 to 6 weeks to maximize yield.
• Plan your postemergence program to control tough weeds like Palmer amaranth, waterhemp and ragweed so they don’t escape being killed and come back to impact yield.

Today, the economics again seem to favor more soybeans in the rotation. Soybean yields are coming up with better management with the corn to soybean yield ratio approaching 3.2 to 3.5 to 1, down from 3.8 to 4.0 to 1 (think 200-bushel corn and only 50-bushel soybeans). And soybean prices have stayed higher relative to corn at a ratio of 2.75 to 3.0 to 1 instead of 2.0 to 2.5 to 1. This is making growing soybeans more attractive.

Drop in a comment below and let us know the strategies you plan to adopt to maximize bean yield while keeping a lid on costs to make a profit per acre.

Agronomist Dr. Daniel Davidson posts blogs on agronomy-related topics. Feel free to contact him at djdavidson@agwrite.com.