Perhaps you’re already acquainted with the wild world of theoretical yields. A theoretical yield is a measure of the genetic potential a plant has, if absolutely nothing hampered yield — not the growing season, environment or pests. Can you guess what soybeans’ theoretical yield is? Roughly 350 bushels an acre. Outlandish? Well, it sort of is, but the top soybean yield in the United States has topped 150 bushels an acre, can Ontario’s farmers push ever closer? If so, how?

In this episode of the Soybean School, Bernard Tobin asks series regular Shawn Brenneman, agronomist with Syngenta, first for his start-of-planting prediction and what pest risks are lurking beneath the snow pack, and then how farmers can start to chip away at sky-high soybean yields.

Scouting is absolutely key, says Brenneman, as your crop should “want for nothing” if you’re after top yields. What’s more, farmers need to balance top yield potential with pest pressure, from soybean cyst nematode to white mould. And, speaking of scouting, remember that it’s early weeds — those out ahead of or at emergence — that eat the most yield. All that and more, in the video below.

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One thought on “Soybean School: The Theoretical Top End of Soybean Yields And How to Edge Ever Closer

  1. Nice video as always.

    The argument about “potential yield” based on numbers of flowers (and potential pods) is not sensible in my view. It is no trick to make a soybean plant produce large numbers of flowers, but flower number is not the limitation to yield. The main limitation is getting the crop as a whole to produce enough total biomass (and acquire enough nitrogen). Counting the flowers and saying “if only we could make all of those into pods” isn’t related to yield potential. Most crops can already make many more fruiting positions than they can use. Doesn’t matter, and it is not an indicator of yield potential.

    What is right on though is the idea of variety selection, *especially* if you can push maturity a little (by choosing a slightly later variety than you normally would for your region) and planting as early as possible. Like, late April if you can get away with it. The longer that crop is in the field absorbing sunlight and growing, the higher the yield potential. This is the one thing that we know for sure can have a significant positive impact, along with effective weed control as also mentioned in the video. Most other inputs are disappointing in terms of their demonstrated benefits, including inoculants on established bean fields, fertilizer N, and fungicides in the absence of actual disease pressure.

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