Start Date: 2012
Principal Investigator: Dan Kaiser
Organization: University of Minnesota, Department of Soil, Water, and Climate
The research completed to create this report aimed to validate using plant tissue analysis in the evaluation of potential hidden nutrient deficiency problems within fields. These researchers questioned whether plant tissue and the current industry norms are relevant for today’s hybrids and varieties. The study proposed further investigation into three areas of plant analysis: 1) How variable are nutrient analyses for different corn hybrids grown under the same conditions? 2) Can grid sampling with plant analysis aid in the assessment of potential nutrient deficiencies for corn and soybeans? 3) And how do current values from mid-season tests compare to established industry norms?
Determine standard values for nutrient concentration in the corn ear leaf at the R2 growth stage
Compare tissue analysis values among corn hybrid within and across locations
Evaluate an intensive plant sampling program for helping to predict nutrient deficiencies and the effect on farmers’ fields for both corn and soybean
Utilizing pre-existing field trials, collect plant tissue samples to determine sufficiency level values for N, P, K, and S, and then compare these with sufficiency levels that are currently being recommended to growers
Hybrids significantly vary in their ear leaf nutrient concentration, and the differences are not reflected in final yield.
For southern Minnesota locations, potassium (K) and iron were the only nutrient concentrations found to be stable across locations.
Data indicates that single sufficiency values for nutrients may not be adequate, as each hybrid might have its own sufficiency level for a given nutrient.
Plant mass appeared to be a better indicator for final yields in both corn and soybean fields. However, plant mass was negatively correlated to final plant soybean yield.
Tissue analysis showed some stress in the field, but there was no indication of the cause of the stress or whether it could be alleviated by fertilizer applications.
The sufficiency range for K was found to be lower than the current published values. However, it is not clear whether this is a result of the dry weather conditions.