Tissue testing is often viewed as a reactive tool when problems are observed in a field, but it can be a proactive part of a broader strategy to maximize yields.
In this Soybean School episode, we're joined by Chase Austvold of Lallemand Plant Care in a southern Manitoba soybean field to discuss how tissue sampling can help growers understand crop performance and optimize input decisions during the growing season — and in the following years.
Austvold, who coordinates Lallemand’s trialing program across the U.S. and Canada, shares a three-stage approach on when to tissue sample soybeans:
- V3 to V5 (3rd to 5th trifoliate):
- This early window is ideal for evaluating macronutrients like nitrogen, phosphorus, and potassium, and for checking whether inoculants have worked as expected. Early nodulation is a positive sign, says Austvold, and this timing gives farmers a chance to be both reactive and proactive as they manage yield potential.
- R1 to R2 (beginning flower):
- Once soybeans enter reproductive stages, nutrient demands ramp up. This is the time to focus not only on macronutrients, but also key micronutrients like boron and sulfur. Boron plays a critical role in differentiating tissues, and sulfur and iron are essential to supporting nitrogen fixation.
- R3 to R5 (early pod fill):
- As the crop shifts to pod fill and seed formation, nutrient uptake peaks. While it’s more difficult to react in this window, it provides valuable insight into how different treatments or management strategies have performed. It also supports long-term decision-making by giving growers a full-season snapshot of nutrient dynamics.
A well-planned tissue sampling program can be a low-cost way to monitor crop health and validate how biologicals or other inputs are performing, says Austvold. With weather variability and unpredictable harvest outcomes, tissue data can also serve as a measurement and additional dataset for comparing trials and treatments within a field — before yield results are even available, he notes.
Check out this episode of RealAgriculture's Soybean School for a practical breakdown of when and why to tissue sample, and how it can be proactive tool in optimizing soybeans' potential!
