EVALUATION OF A MODIFIED VARIABLE RATE GRANULAR FERTILIZER SPREADER FOR SPOT-SPECIFIC FERTILIZATION IN WILD BLUEBERRY FIELDS

Abstract

The variable rate fertilizer spreader was modified to control each pair of nozzles for spot-application of fertilizer only in plant areas of wild blueberry fields. The experiments were conducted to evaluate performance accuracy of modified variable rate granular (MVRG) fertilizer spreader. The results suggested that the MVRG fertilizer spreader performed efficiently in detecting bare spots/weed patches and clay filler application only in green grass/plant areas. Two wild blueberry fields were selected to evaluate the impact of MVRG spreader on nutrient leaching through small bare spots/weed patches. Management zones were delineated on the basis of slope variability. The MVRG spreader significantly reduced the nutrient loading in subsurface water samples collected from the bare spots/weed patches. Based on the results obtained, it can be concluded that the fertilization in wild blueberry fields using MVRG fertilizer spreader can result in the protection of subsurface water quality, thus protecting the environment.