Maximize Soybean Yields

Historically, soybeans have been viewed as an efficient option in a crop rotation, providing adequate returns with lower input requirements than corn. But that strategy is changing as farmers push the envelope to raise yields and improve ROI on these acres. Soybeans are proving to be a legitimate money maker on par with traditional cash crops. In fact, earlier this year, a Georgia farmer set a new world record for soybean yield with an astounding 206 bushels per acre.

While an extraordinary example, it gives us a glimpse of soybeans’ yield potential when purposefully managed. This systems approach to growing soybeans includes close attention to variety selection, planting date, weed, disease and insect management, and, of course, a commitment to crop nutrition.

Back to Basics

Nutrient availability is one of the most important factors in making or breaking soybean yields. Like an elite athlete, soybeans rely on a nutrient-rich diet to fuel peak performance, from planting through pod fill.

Soil sampling can illuminate an array of yield-limiting factors. Conducting these tests in the fall provides a baseline for your nutrient profile. This gives retailers a course of action to address with customers when discussing their goals for the upcoming season and talking about their fertilizer needs (right nutrient sources, rates, timing and placement).

Remember the Importance of Sulfur

While nitrogen, phosphorous and potassium get the most attention, don’t forget about sulfur. As the “fourth macronutrient,” sulfur plays a critical role in the development of high-yielding soybeans. Necessary for growth during the vegetative and reproductive stages of soybeans, sulfur is essential for the synthesis of chlorophyll, as well as sulfur-amino acids and proteins that are critical for plant growth. Sulfur is also required for root nodulation, which provides biological nitrogen fixation, supplying about half the nitrogen used by the average soybean crop.

In previous decades, crops received most, if not all, of their sulfur requirements from atmospheric depositions. However, the Clean Air Act created stricter emissions regulations that reduced atmospheric sulfur depositions across the United States, thereby decreasing the amount of annual sulfur available to plants from the atmosphere (by over 50% in the past decade) to less than five pounds per acre. This reduction increases the need for supplemental sulfur application across many crops, including soybeans.

A Strong Start Ups Your Odds of a Strong Finish

A major agronomic shift in soybean production is early planting, which allows for increased canopy and, therefore, increased photosynthesis by the time the crop hits the reproductive stage. This also means planting in wetter and cooler soils, which can result in slower organic matter mineralization and lower levels of plant-available nitrogen and sulfur during this critical time for seedling development and root nodulation.

Fortunately, an ammonium sulfate (AMS) application anywhere between a few weeks before and a few weeks after planting can provide plant-available sulfur to the crop during this key time frame, giving it a jump-start by supporting early-season growth and healthy nodulation.

Since soybeans can’t make their own nitrogen until the V3 stage, the early AMS application can also provide the nitrogen the plant needs for early growth, before nodules are ready to fix atmospheric nitrogen. Additionally, AMS can also help unlock phosphorus and micronutrients like boron, zinc, and manganese – enabling plants to absorb these nutrients along with the sulfur and nitrogen.

Address In-Season Nutrient Needs

In-season, it can be beneficial for farmers to conduct tissue sampling and testing to better understand how their soybeans are taking up nutrients. Based on the results, there might be a need to topdress a readily available fertilizer like AMS. With easily accessible sulfur and nitrogen, AMS can be topdressed around bloom to support soybeans during pod fill. Taking into consideration that half of the nitrogen and sulfur in the soybean grain is taken up after flowering, topdressing might be a relatively efficient way to ensure that these two essential nutrients are not lacking on high yield potential crops.

Timely applications of ammonium sulfate can help farmers achieve higher soybean yields. Over the past three years, AdvanSix has worked with progressive soybean farmers to see how they can promote more consistent and healthy crops and, ultimately, push yields.

Learn more about how these farmers boosted soybean plant health and maximized yields by putting AMS to the test at supplementyoursoybeans.advansix.com.