By: Andrea Rice, Director of Research, Education, and Outreach, Missouri Fertilizer Control Board
The increase in use of nutrient management plans and precision application of fertilizers has led more producers to look at plant tissue sampling to fine tune nutrient application. With crop advisers/consultants and scouting programs more available producers are able to seek higher yields while decreasing input costs to manage narrow profit margins.
Implementing tissue sampling can assist producers with determining fertilizer effectiveness, if there is a need for additional nutrients, and planning nutrient management for future years. Growing plants provide insight on the nutrient profile and assist in developing an efficient and effective crop production plan.
How do I utilize tissue samples?
Tissue sampling can increase yield potential as plant growth is restricted in three ways when one or more of the 16 required elements
- are limited
- are present in abundance, which could lead to a toxic environment
- are present in adequate amounts, but out of balance with other elements.
Results of nutrient deficiency, toxicity, or imbalance progress through ____ stages if the condition continues (1) reduction in plant growth and (2) visible signs of nutrient deficiency or toxicity appear with a reduction in yield. It is possible for an imbalance to not be expressed visibly but will still restrict yield as a “hidden hunger”.
Samples for tissue analysis will likely be tested for 10 elements: nitrogen, phosphorus, potassium, calcium, magnesium, iron, copper, boron, and zinc. Information from the tissue analysis will provide analytical results and an interpretation of what nutrients plan changes are necessary to improve yields.
How do I prepare to take a sample?
- Check to be sure plant parts being sampled are free of soil, fertilizer, or spray residue.
- If needed, clean plant parts with a dry brush. A damp cloth can be used if a brush is not available.
- To avoid contamination, use clean paper bags (kraft bags are ideal) or envelopes for mailing collected tissue samples. Bags sized 10-12 pounds are best for corn whereas smaller bags are suitable for soybeans and other crops.
How do I collect my sample?
If using University of Missouri Extension or if your private lab does not provide instructions, follow these steps:
- Carry an open bag – Allow the leaves to go into the bag as the tissue is removed from the plant. Leave the samples loosely in the bag for air drying to resist mold occurrence.
- Leave the bag open – Once the sample is collected, leave the bag open until ready to ship or drop off at your local MU Extension location.
- Air dry the samples – If possible, allow the samples to air dry in a room or shed as free of dust as possible. Refrain from air drying in areas with chemical storage. Place the open bag on a clean wooden surface and allow to dry 24-48 hours.
- Deliver or mail the samples – Once samples are air-dried, they can be dropped off at your local MU Extension center in the bags used for collection and drying. If mailing the samples, larger pieces of tissue may need to be broken into sections to lie flat on the bottom. The bag can be folded and placed in a small box or manila envelope for mailing. Commercial labs will likely provide a kit for returning samples.
Future posts will include details on how to collect samples from specific crops.