10 Things to Consider to Increase Your Soybean Yields – Part 2 of 2

As shared in Part 1 of our two-part article, the genetic potential within a seed is not realized within a growing season due mainly to abiotic stresses (temperature, wind, sunlight, flood, drought, salt, minerals, etc). Helping reduce stress can have a positive impact on soybean yields.

In addition to selecting top genetics, here are 10 things to consider to increase your chances of higher soybean yields:

1. Trash Management
2. Time of Planting
3. Seed Bed Preparation and Planting Depth
4. Seed Singulation, Spacing and Depth for Even Emergence
5. Seed Treatment
6. Double Inoculation
7. On-Seed Fertility
8. In-Season Fertility
9. Early Weed Control
10. Foliar Fungicide

We covered #1 to #6 in Part 1, so let’s expand on #7 through #10.

Perhaps the least explored “thing” in pushing for bigger soybean yields is fertility. When it comes to fertility there are certain things that we know. We know that soybeans perform well in soil with pH levels between 6.5 and 7.5. We know they uptake 5 lbs nitrogen, 1 lbs phosphate, 3-3.4 lbs potash, and 0.35 lbs sulphur to produce a bushel. Soybeans also require (on a per-bushel basis) 2.4 lbs calcium, 0.67 lbs magnesium, 0.03 lbs iron, and small amounts of zinc and boron. Properly inoculated soybeans under ideal conditions can fix most of their nitrogen, but they also take up residual N and mineralized N from the soil. Soybeans are known to be excellent scavengers. They can source P, K, S, and micronutrients from soil residuals. It is important to acknowledge that soybeans require nutrients. Often more than we provide them. Did you know that of twelve essential nutrients, soybeans are highly responsive to eight, canola seven, and wheat five? We know a lot, but there are still questions we need to ask ourselves:

Are the macro and micronutrients readily available to the soybean plants?

How can we enhance the soybean’s ability to uptake its required nutrients?

Should we consider adding macro or micronutrients to increase our yield potential?

A soil test is key information in starting to put your soybean fertility puzzle together.

7. On-Seed Fertility

• Soybeans require nutrients and water. A nutrient seed dressing can be a great way to get your crop started, provide the plant with nutrients, and enhance the soybean’s ability to increase uptake of its required nutrients and water. Nutrient seed dressings are designed to deliver essential nutrients in the proper form and proper ratio to help drive early root development. Building root mass early and extensively is super important to plant health and driving yield. An extensive, healthy root system results in expanded root surface. The more root surface a soybean plant has, the more it can uptake nutrients and water. This is beneficial in high-yielding and in drier conditions. A healthy root mass also allows for more nodulation and nitrogen fixation.

8. In-Season Fertility

• Do you eat one big meal at breakfast or multiple meals a day? Do you frontend load your fertility or apply it at different stages? It is a well-documented debate. Given the enhancements in genetic yield potential while knowing soybeans have high nutrient demand, feeding your crop with foliar fertility may have its benefits. If you are considering this, it should be a component of a complete crop nutrition program, as most of your key nutrients come from the soil and nitrogen fixation. Foliar application of nutrients can boost plant health, particularly when deficiencies occur or when root growth is slow during the start of the reproduction stage. Application timing is critical. In the case of nitrogen and/or boron, the best window is between R2 – R3 when the pods begin to fill. Micronutrients, such as boron, copper, iron, manganese, and zinc, may also prove to be beneficial. Since soybeans require small amounts of micronutrients, foliar application is sufficient to improve plant health. We have lots to learn on the benefits of in-season fertility, and more questions to ask. Having said that, we do not just eat a big breakfast and nothing else for the rest of the day, so should our soybeans only be fed once?

9. Early Weed Control

• Early weed pressure can have a significant negative impact on soybean yield. Growers can loose 0.5 to 2 bushels per day! Research has shown that a soybean plant can sense weeds growing on the soil surface before it emerges and, as a result, will start to change its physiology. When the plant detects weeds during the early growing stage, from the first to third trifoliate (V1 to V3, known as the Critical Weed-Free Period), it starts to reduce yield potential based on the competition from the surrounding weeds. Cultural practices like row spacing, plant density, and variety selection, along with early application of herbicide trait technologies, such as Roundup Ready 2 Xtend Crop System or Enlist E3 Weed Control System, can play a key role in helping growers Start Clean and Stay Clean throughout the critical weed-free period.

10. Foliar Fungicide

• To spray or not to spray? That is the question. When it comes to foliar fungicides there is always a debate on whether or not they provide a return on investment. When looking at the use of a foliar fungicide on your soybeans, you should consider the following:
• Disease History and Prescence. Take into consideration not only the disease history of your field, but the prevalence of soybean diseases across Western Canada. Presently in Manitoba there are seven fungal diseases that can impact soybeans. Soybeans can host one or multiple diseases at the same time or throughout the growing season. Higher severity and number of diseases will have more negative impact on yield.
• Weather. As a rule of thumb, warmer and higher humidity leads to more disease pressure.
• Variety Selection. Some varieties are more resistant and some are more susceptible than others.
• Row Spacing. Wider row spacing allows for better air flow through the canopy potentially reducing disease pressure. Narrow row spacing limits air flow increasing potential disease pressure.
• Overall Plant Health. Fungicides improve overall plant health and there may be potential synergies with other products, such as foliar fertilizers, for example.
• Fungicide Products. Good options are available. Growers can select a broad-spectrum product. Follow the label, but these are typically applied at the R2 stage (full flower) to R3 (first pod). Growers can also select fungicides more targeted for white mould.

There are no silver bullets or guarantees to increasing yields. We trust that we have provided you with “10 Things to Consider to Increase Your Soybean Yields.” We are excited to try these considerations. This summer, NorthStar Genetics will help growers push for bigger yields in our NorthStar Genetics Soybean Yield Challenge. For more details, please check our website nsgcadev.wpengine.com, follow us at @NSGeneticsCA, or contact your NorthStar Genetics representative. We Know Beans!