Markus Braaten, Crop Manager of Cereals and Canola for Yara North America, started his session on day two of the Crop Intelligence Annual Summit with a strong point that everyone would take home with them— “you can’t manage what you don’t measure.”
But, what are we measuring and what are we managing? We should be measuring soil moisture while managing how we maximize photosynthetic efficiency.
We’ve been taught about photosynthesis since we were in grade school—where the plant uses carbon dioxide and water and acts as a vehicle to produce carbohydrates and oxygen as a byproduct. However, Braaten noted, this reaction is more complicated than just sun, water and air.
Nutrients play a critical role in photosynthesis. So, how do we manage ensuring that all the nutrients are there? Braaten asked us to challenge our usual starting point—the soil test.
He explained that, from having looked at tens of thousands of soil tests in his career, lots of things that affect crop productivity are not in a soil test. This includes soil ecology, texture, topography, slope aspect and depth of root restriction. He also added that, while pH, sodium and soluble salts are indicated on soil tests, they often go unobserved.
Braaten continued to unpack the concept of soil moisture, noting that if your soil moisture is in the field capacity realm (rather than at saturation or at permanent wilting point), then your soil moisture is no longer a nutrient limiting factor and you need to consider other nutrients.
So, what then is your limiting nutrient? Where do you focus? How do you begin to measure and manage the next limiting nutrients?
Braaten stated that we need to look at the mobility of nutrients in both the soil and in the plant and be cognizant of how they move. High mobility nutrients in soil include nitrate, sulfate, chloride and boron. And in plants they include nitrogen, phosphorus, potassium, magnesium, molybdenum and chloride. High mobility of nutrients in plants means that the plant itself can serve as a conduit for nutrients.
He also noted that it’s important to build balance into your entire fertility program. While there are often conversations around whether having all these nutrients is important or not, he states that they are truly all essential.
To support the importance of these nutrients, Braaten showed a tissue test study that outlined the occurrence of micronutrient deficiencies in Canadian canola fields. The study revealed that 28% of fields had a soil test level that indicated the deficiency of boron—which means if you don’t supply it with boron, you’ll end up having a yield drag. Similar points can be made with trends in phosphorus and potassium deficiencies. So, while you may have the moisture you need to produce additional yields—if you don’t have the nutrients there as support, you’re leaving money on the table.
Concluding the session, Braaten asked the audience to consider micronutrient and foliar nutrition. He added that there is a need for proactive foliar nutrition because your crops will likely experience nutrient deficiency at some point in their life cycle.