Plants Sampling Service
For most plant analysis, the leaf is analyzed for all macro and micro nutrients (N, P, Ca, Mg, Na, K, Fe, Mn, Zn, Cu, B, S). The levels of these elements indicate the nutrient status of the current crop.
The petiole or midrib is tested for nitrate nitrogen (NO3-N). Additionally, phosphate phosphorus (PO4-P), potassium (K), sulfate sulfur (SO4-S) and chloride (Cl) levels can be determined from the petiole analysis. Testing the petiole provides an early warning. If nutrient levels are low, the leaf will soon become deficient.
Nitrate levels of the soil can also be useful in making nitrogen recommendations during the growing season.
When a nutrient deficiency is suspected, samples should be taken from the affected area as well as from normal plants in the same or adjacent field. Plants sampled should be at the same growth stage. A soil sample should be taken from the affected area at the same time.
Plant Sampling Guide:
- Walk the field in a V or X or diagonal-line pattern collecting samples from various rows in the field.
- Don’t take samples from border rows or within 50 feet of the end of the row.
- Sample the proper plant part.
- Collect 20 -30 leaves and/or petioles.
- Separate the leaf from the petiole or midrib immediately.
- Select plants that represent the average condition of the entire field.
- Don’t sample insect damaged or diseased plants.
- Don’t collect leaves that are dusty or dirty.
- Collect the sample during daylight hours.
- Use a porous holding container for the sample like a paper bag.
- Don’t store the sample in plastic.
- Record the growth stage of the plant.
- Record water stress if present.
- Note any recent fertilizer application.
- Deliver samples to a laboratory within 24 hours of sampling.