zone based tissue tests
Zone based soil sampling can provide insight into fertility issues. Tissue testing those same zones can make that picture a lot clearer. We make a lot of assumptions on what the crop needs for fertilizer, apply the fertilizer by variable-rate, then tissue sample to see what the plants are telling us.
Copper has shown up deficient in soils in NE Saskatchewan in soil and plant tissue tests. Copper research on the soils in question does show responses. Therefore the tissue test is helping us to clear up any unsurety of a response. The tissue test in the field shown above came from soils that showed no copper deficiency from soil testing. Many zones were borderline and deficient. More work should be done in this field to confirm what is happening but without the tissue test we would never had known of the possible issue.
Boron is an example of a nutrient that sometimes appears deficient on well drained areas of the field with low organic matter. However, we have never had a tissue test on canola show a boron deficiency. Need we worry about applying it? Even the most aggressive fertilizer users show no areas with low boron levels.
Zone based tissue tests are a solid complement to our variable-rate fertilizer strategies.