Know what was sampled
Leaf (tissue) analysis measures the nutrients in leaves collected from a block at a particular time. The guidelines those results are compared against were built from a specific kind of leaf, taken at a specific stage. For almonds and many other tree crops, that’s a mid-summer sample of fully expanded leaves from non-fruiting spurs. Sample a different leaf, or at a different time, and the numbers won’t compare cleanly.
Read the units
The major nutrients (nitrogen, phosphorus, potassium, calcium, magnesium and sulfur) are reported as a percent of dry weight. The micronutrients (such as boron, zinc, manganese, iron and copper) are reported in parts per million. A “low” potassium and a “low” zinc live on completely different scales, so read the flag, not the size of the number.
Ranges and flags
Each result is compared to a range for that crop at that timing: deficient, adequate or excessive. A good report puts the result, the target range and a flag side by side, so you can see in a few seconds where you stand. OK means move on. Low or high means there’s a conversation to have.
What a flag doesn’t tell you
- Why. A low number can be a supply problem (not enough in the soil), an uptake problem (roots, water, salts or pH), or a heavy crop pulling the level down.
- Whether it’s worth fixing this season. Some corrections only pay if they’re made in time.
- Whether it’s real. One sample is one data point. Compare it with the same block last year and with what you see in the trees.
Read it alongside
Soil results, irrigation, crop load and last year’s leaf numbers for the same block. A trend over several seasons tells you far more than a single snapshot.
Three questions for your agronomist
- What’s the one thing on this page that matters?
- What would you do about it, what will it cost per acre, and when?
- How will we know whether it worked?