Whether monitoring fields from the ground or from up above, you’re bound to find a handful of problem areas that have you stumped. A plant analysis can be a useful diagnostic tool. And in many regions, the window to gather samples is open.
Plant tissue analysis can be an extremely useful tool. It is unique from other crop diagnostic tests in that it gives an overall picture of the nutrient levels within the plant at the time the sample was taken. It allows monitoring the nutrient adequacy in plants and helps identify nutrient deficiencies and imbalances.1 It also can confirm toxicities, identify “hidden hunger,” help evaluate fertilizer programs, study nutrient interactions and determine the availability of elements for which reliable soil tests have not been developed.
Plant analysis is different from tissue testing in that it is a quantitative laboratory analysis. Tissue testing refers to semiquantitative, quick tests of plant sap carried out in the field for trouble-shooting purposes.
Quality control — critical to success
It’s important to follow correct sampling techniques. This handy guide from the University of Wisconsin Soil and Forage Lab will help direct success. Be sure to sample at the recommended growth stage and from the part of the plant as directed by your testing lab. For example, plan to sample corn before tasseling or from tassel to silking. For soybeans, it’s prior to or at initial flower development. Errors or carelessness in selection, collection, handling, preparing or shipping plant tissue for analysis can result in unreliable data. Here are some additional considerations:
- Avoid sampling plants obviously stressed from causes other than nutrients, such as disease or insects.
- Sample normal and abnormal plants from different parts of the field.
- Include a soil sample, which can be useful for correlating with plant analysis results to pinpoint a nutrient problem.