Variable Rate Fertilizer Application in Wild Blueberry Fields: Impacts on Plant Growth and Yield

Abstract

Abstract. A wild blueberry field was selected in central Nova Scotia to examine the effect of VR fertilization on plant growth and fruit yield as compared to uniform fertilization. The variation in slope was mapped and management zones were delineated. The field was divided into two sections (VR and uniform). The GPS-guided prescription map was generated in ArcGIS 9.3 for VR treatment section. Three fertilization rates 200, 150, and 100 kg ha -1 were applied with a VR fertilizer spreader in Z1, Z2 and Z3, respectively. The bare spots and weeds were classified as a separate class in the prescription map and zero rate was allocated. For comparison, growers uniform fertilizer rate of 200 kg ha -1 was applied in uniform treatment section. Soil samples were taken from selected sampling points before and after the fertilization, and soil properties and levels of soil nutrients were determined. Plant growth parameters and fruit yield were also collected from selected points. Plants in uniform treatment sections were taller than VR treatment sections in low lying areas. Plant density, number of branches and buds were non-significantly affected with fertilizer treatments. Plant growth parameters were significantly correlated with soil properties and soil nutrients in both VR and uniform treatments. Fruit yield in VR treatment section was non-significantly different than uniform treatment, although mean fruit yield was higher in VR section. VR fertilization saved 41% fertilizer in selected field. Results of this study suggested that VR fertilization could increase fruit yield and reduce fertilizer usage in wild blueberry fields.