What impact do fungicides, plant population, and row spacing have on your soybean yields?
The Iowa Soybean Association (ISA) has been working with growers in the state for years to help assess the impact of crop inputs and management options. In this episode of Soybean School, ISA researcher Tristan Mueller joins Real Agriculture’s Bernard Tobin to discuss results from the association’s on-farm test plot program and how they compare to Ontario.
When it comes to impact of fungicides, the story is very similar to what growers experience in Ontario – about an average two bushels per acre benefit. Population trials based on four years of data reveal Iowa farmers see little benefit in planting at higher seeding rates – 130,000 seeds per acre versus 160,000. Going with the higher rate yields, on average, just an extra 0.7 bushel.
Mueller notes that about 60% of Iowa soybean fields are planted in 30-inch rows. The association’s research indicates that growers see about a three-bushel yield increase when they move to 15-inch rows. Overall, based on the trials, Mueller concludes that management changes continue to yield minor responses. Indeed, there is no silver bullet when it comes to managing soybeans.
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