The Unlock

Why nutrients in your soil don’t always translate to nutrients in your crop 

What happens when the soil test says one thing, and the crop shows another?

By mid-season, this is a common situation across Western Canadian fields. Crops may begin to show signs of nutrient stress, uneven growth, and variability, even where soil tests indicate adequate or high levels of micronutrients.

In most cases, this isn’t a question of what’s in the soil.

It’s a question of what the crop can actually access.

Presence vs availability

Soil tests remain an important tool in crop planning. They provide a snapshot of nutrient levels and help guide fertility decisions.

But nutrient presence doesn’t always mean nutrient availability.

For micronutrients to be taken up by the plant, they must be:

• in a plant-available form
• positioned within the active root zone
• accessible under current soil moisture and temperature conditions

At any given time, a portion of nutrients in the soil can be temporarily unavailable due to interactions with soil chemistry and environmental conditions.

Why the gap shows up in-season

As crops move through the growing season, they rely fully on root uptake and soil nutrient supply. This is where differences in availability begin to show up more clearly.

In Western Canadian environments, several factors can influence this:

• Soil pH: Higher pH soils can reduce the availability of micronutrients like zinc and iron
• Moisture conditions: Limited moisture can restrict nutrient movement toward roots
• Temperature: Cool soils can slow both root activity and microbial processes
• Soil biology: Microbial activity plays a role in nutrient cycling and release

Even when nutrients are present in the soil, these factors can limit how effectively they move into the plant.

What this looks like in the field

This gap between presence and availability often shows up as:

• uneven crop colour or striping
• areas of slowed growth
• variability across similar soil zones
• symptoms that don’t align with soil test expectations

These patterns are not always the result of insufficient nutrient application, but rather differences in how accessible those nutrients are under current field conditions.

Why this matters for crop performance

Mid-season variability can influence how the crop responds to stress later in the season.

Crops with consistent access to nutrients tend to:

• maintain more uniform growth
• respond more effectively to environmental stress
• continue developing without interruption

Where nutrient access is limited, crops may struggle to keep pace, even when fertility programs were followed perfectly.

Connecting early decision to mid-season outcomes

In many cases, what’s showing up in July can be traced back to how nutrient availability was supported earlier in the season.

Not just what was applied but how those nutrients were positioned to remain accessible as conditions changed.

Understanding this connection helps shift the focus from reacting to symptoms to evaluating the system behind them.

A practical way to approach this stage

Mid-season is a valuable time to observe and interpret.

Where is variability showing up?
What patterns are consistent across the field?
Do those patterns align with soil conditions or environmental factors?

These observations can help explain what the crop is experiencing and provide useful insight for future planning.

Final Thought

The soil test provides part of the story.
The crop provides the rest.

Understanding the gap between presence and availability is key to interpreting mid-season performance and building more consistent outcomes over time.

Out in the field?

We're following how these early-season decisions show up as the crop develops.

Seeing something you want a second opinion on?

Great conversations start there.