The feasibility of determining foliar nitrogen, phosphorus and potassium contents using existing hyperspectral technologies in wild blueberry fields

The ability of hyperspectral technologies to estimate wild blueberry leaf tissue N, P and K levels was investigated during the 2004-2005 growing seasons. Soil applied N, P and K were applied in the spring of 2004, and influenced foliar N, P and K contents only at tipdieback. There was no effect of the treatments and no significant correlations of foliar N, P and K levels with respect to berry yield. However, the foliar nutrient levels did provide useful insights on plant growth and development. Foliar nutrient level estimations were obtained using a CASI sensor, Personal II radiometer and FieldSpec Pro radiometer. Only N and P levels could be accurately determined. NDVI was inadequate in quantifying N levels. Challenges with data collection, processing and statistical analysis were limiting factors. If remote sensing is to be further studied in wild blueberries, field level use of radiometers appears to be justified.