By Thom Weir, Senior Precision Agronomist
This is part two of five of Back to Basics: Soil Fertility that deals with soil and fertility. We will discuss Phosphate today as it is the nutrient that I fear is most deficient on farms across the Canadian prairies and the northern Great Plains area of the US.
It’s not the nutrient that unlike nitrogen, when missed, shows deficiency symptoms across the field. Phosphate deficiencies are more subtle and usually go unnoticed. In fact, I have only seen what I would identify as significant phosphate deficiencies four to five times in my career as an Agronomist. Interestingly, three of these fields showed up in the same year.
The year was 2009. If you recall, fertilizer prices spiked in 2008 to the point where many growers simply didn’t apply phosphate, and the sky didn’t fall in. In fact, because some growers didn’t see any issues, they eliminated their phosphate again in 2009. That year, I was called out to investigate fields that showed very slow growth compared to neighbouring fields. After investigation, soil and tissue sampling, I determined the stunted growth was due to phosphate deficiencies…