- Variety Selection
- Row Spacing
- Plant Stands
- Timely Planting
- Plant Nutrition
Variety Selection
Choosing the right soybean variety is a key factor in attaining a good yield. Varieties should match local soil and climate conditions while resisting common diseases such as white mold and sudden death syndrome.
Row Spacing
“Row Spacing is huge,” underlines Casteel. “I think about that especially as we go further north. You want to harvest sunlight. That's your job. You want those soybeans to harvest sunlight by the time they're flowering out the top. My cutesy saying is I want them green to die by the 4th of July.”
Casteel prefers narrow rows, ideally around 15 inches, which help crops close their canopy faster, capture more sunlight, and suppress weeds.
Casteel says that you want the soybeans canopied by the 4th of July, because then farmers are harvesting as much sunlight as possible. “Developing flowers that are now going into your money makers of pods and seeds.”
Plant Stands
With regard to plant stands, he noted to factor in seed rate which will change depending on the equipment utilized in your field: drills, planter, air seeders.
Timely Planting
Casteel says that timely planting can make as much of a difference at harvest as 48 bushels/acre. He also noted the importance of photosynthesis and heat units. He noted for example, that farmers who grow next to a highway that has a billboard sign that has a light on it, often experience that the soybeans do less well because they have less of a rest period at night – the light disturbs the photosynthesis process.
The soybean extension specialist also noted that heat units are becoming increasingly important. More heat unit accumulation leads to more nodal development for the trifold nodes.
Plant Nutrition
Balanced fertility is critical. Adequate sulfur and nitrogen improve nodulation and protein levels, especially in cool or high-residue soils where sulfur can be limited. Fields with sufficient nutrients maintain green leaves longer, allowing more seed development and larger harvests.
Drainage
Good drainage was added to the list, as it supports healthy root systems that access water and nutrients during dry periods, helping plants thrive through late season seed fill when water demand peaks.
Weed and pest management
Weed and pest management also influence yield. Clean fields reduce competition for nutrients and light, while timely fungicide or insecticide applications can protect pods from damage when pest levels approach thresholds.
Casteel recommends monitoring plant stands carefully. He says a final stand of around 85,000 plants per acre is typically enough when seeds are planted at proper depth and spacing. Uniform emergence and strong early growth help soybeans resist stress and maximize production.
By combining timely planting, careful variety selection, balanced fertility, effective drainage, and integrated pest management, farmers can consistently achieve strong soybean yields and improve long-term soil health.
Watch the video of the Shaun Casteel’s presentation at the 2025 Great Ontario Yield Tour.