Sap Analysis – New Technique for Assessing Nutrient Levels.

Sap analysis is a new method to evaluate nutrient levels in plants. Results show deficiencies several weeks earlier than tissue testing and also has indicators that reveal plant’s general metabolic health. The method of evaluating nutrient levels in plants is traditional plant tissue analysis. Specific parts of plants are sampled at specific times and then sent to a laboratory when there are dried, ground and then nutrients are extracted and measured and either reported as percent or ppm. Traditional tissue sampling reflects what nutrients the plant has taken up to that date but doesn’t reflect what nutrients are immediately bioavailable. Sap analysis is a new technique that collects sap from leaves of plants. Both older leaves and newer leaves are sampled and measured at key times during the vegetative and reproductive development of the plant. A field experiment was conducted in corn and soybeans in 2015. Corn was sampled at V6, V12-V14, VT, R2 and R4. Soybeans were sampled at V6, R1, R2, R4 and R6. Leaf tissues were analyzed by both sap analysis and traditional tissue analysis. Soil was also sampled and analyzed for its nutrient profile. Samples for sap analysis were submitted to Crop Health Labs in Akron, Ohio. Samples for tissue analysis and soil analysis were submitted to Ward Laboratories in Kearney, Nebraska. Nutrient profiles in the sap, tissue and soil are compared and evaluated across the different development stages in the crop plants.