ILSOYADVISOR POST

What Recent Experience Reminds Us About Raising Beans

The agricultural industry spends a lot of time contemplating which “silver bullets” or “golden inputs” should be used in soybean production. As an industry, we are notorious for tweaking the system —but we often forget how important it is to first embrace the fundamentals of soybean production.

The past few growing seasons remind us of the “first steps” toward strong yields and management considerations that should be embraced before we experiment with “everything else.” Those considerations are grounded in a central concept—a very high percentage of pods naturally abort, and we must offset that by increasing overall field pod count. A few examples of this season-long pod count battle come to mind.

First, successful soybean production hinges on solid, stewardship-minded weed management. Weeds, unlike other pests, have the ability to nearly zero-out yields when left unchecked. Their competitive nature for moisture, nutrients, light and space can limit soybean leaf area and soybean pod count. Starting weed free and staying weed free is key, but that work must be done in a way that applies multiple modes of action in-season. This in-season herbicide cocktail is our best strategy to keep fields weed-free and maintain the viability of our weed management toolbox.

Weather can make it difficult to get beans planted earlier—but earlier planting should be a goal for every grower. In recent growing seasons (5 of the last 6 years, for instance), earlier planted soybeans showed a very direct and positive yield response. It’s a relationship that adds photosynthetic area and, more importantly, increases node count. Because node count can translate into higher pod count, earlier planting represents a very low-cost method by which to often secure higher yields.

Protecting stand is critical. Reductions to stand can translate into reduced pod count which makes natural pod attrition that much more painful. The advent of a broad seed treatment toolbox has allowed growers to plant earlier and trim seeding rates. These tools help minimize the risk of reduced stand. As with all other soybean management tools, we must move, as an industry, toward a cocktail of thoughtfully prescribed seed treatments if we hope to avoid tolerance and resistance.

Growers need to always keep a wary eye out for the ever-changing nature of pest pressure. Maintaining photosynthetic area is critically important to increasing the likelihood of higher pod counts. Plenty of recent examples come to mind, and all such examples demonstrate that the spectrum of soybean pests is not static. While physiological explanations can be made for responsiveness to fungicide and fungicide-insecticide applications, the changing nature of the pest environment reminds us why we explored using those tools to begin with—the management of disease and insects.

Nutrient demand will increasingly become a consideration in soybean production. Phosphorus and potash will always be important, but someday sulfur will become a necessary input in beans as well. We are in a period of transition. Nature may supply a couple dozen pounds of sulfur each year thanks to a cleaner environment, but 80-bushel soybean yields begin to demand nearly the same amount. Testing and retesting with strip trials will be needed every few years to detect that moment when sulfur tags alongside P and K.

Mitigating weather-related risk is critical—I’m specifically referring to the reproductive period. From season to season, late July to late August can tend to be one of the most variable periods (day-to-day) for rainfall. Moisture supply is strongly correlated to maintaining pods and increasing overall seed count per unit of area. Because we cannot predict when moisture stress will come during that month-long period, we cannot estimate which portion of the soybean maturity spectrum will dominate yield each season. Our only alternative is to spread our risk by planting a span of soybean maturities.

Finally, multiple additional considerations could be addressed following the past few years of soybean growing experience. However, each of those considerations ultimately force us to ask a very important question. In our battle to increase pod count, do our decisions mitigate or gamble with risk? We must always seek to do the former and try our best to run away from the latter.

You can learn more about this topic by watching the latest ILSoyAdvisor Webinar.


Matt Montgomery

Matt Montgomery is a Field Agronomist with Pioneer serving growers in west-central Illinois. He previously served as a sales agronomist in both Illinois and Missouri. Before serving as an industry agronomist, he worked in agriculture for nearly twenty years within the University of Illinois’ extension system.  



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