Effect of Split Variable Rate Fertilization on Wild Blueberry Plant Growth and Berry Yield

Abstract

Abstract. Traditionally, wild blueberry growers apply fertilizer uniformly without considering the substantial variation in soil characteristics, topographic features, and berry yield. Occurrence of heavy rainfall events, gentle to severe topography along with high proportion of bare spots and weed patches emphasize the need for variable rate split (VRS) fertilization. The VRS fertilization has a potential to improve fertilizer use efficiency and reduce environmental impacts. Two commercial wild blueberry fields were selected in central Nova Scotia. Fields were divided into three sections [VRS section, uniform rate split (URS) section, and uniform rate (UR) section]. Fertilization was performed by following the global positioning system (GPS) guided prescription map. Soil samples and plant growth parameters were collected during the vegetative year and berry yield samples were collected during the crop year. The experimental design used for this study was split-plot design and the analysis of all collected data were performed using SAS (SAS, 2010) at 5% level of significance. Plant density and plant height were non-significantly different under all slope zones of VRS, URS, and UR treatment sections. Plants in URS and UR sections were taller than VRS sections in low lying areas. Although there were non-significant differences for berry yield in all slope zones of VRS, URS, and UR fertilizer treatments, the mean berry yield was higher in VRS section as compared to the other sections. Significant correlations were observed between soil properties and plant growth parameters under all treatment sections. The VRS fertilization saved 39% and 42% fertilizer in Cooper (field-1) and North River (field-2) fields, respectively. Based on the results of this study, it can be concluded that the VRS fertilization in wild blueberry fields could reduce fertilizer usage without affecting the crop productivity.