Delineating Management Zones for Site Specific Fertilization in Wild Blueberry Fields

Abstract

The concept of management zones has been proposed as a solution to the problems associated with the soil variability to more efficiently apply agricultural inputs on a site-specific basis. This study was designed to characterize and quantify the spatial variation in soil properties and wild blueberry fruit yield and to delineate management zones for site-specific fertilization. Two wild blueberry fields were selected in central Nova Scotia, and a grid pattern (15 xis m) was established at experimental sites to collect soil and fruit yield samples. The soil samples were analyzed for ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3--N), pH, electrical conductivity (EC), texture, and soil organic matter (SOM). The volumetric moisture content (theta(nu)) and ground conductivity data including horizontal coplanar geometry (HCP) and perpendicular coplanar geometry (PRP) were also recorded at the same grid points. The location of the sampling points were marked with a differential global positioning system (DGPS), and field boundary, bare spots, weeds, and grass patches were also mapped. The cluster analysis was performed to group the soil and fruit yield data into five zones termed as 'very poor,' 'poor,' 'medium,' 'good,' and 'very good' without prior knowledge of productivity potential with the internal homogeneity and external heterogeneity at a similarity level of greater than 70%. The coefficient of variation, geostatistical range of influence, and kriged maps suggested moderate to high variability of soil properties and fruit yield except soil pH and silt. The results of correlation matrix suggested significant relationships among the fruit yield and the soil properties. The results of ANOVA indicated that the fruit yield, HCP, PRP, theta(v), SOM, and inorganic nitrogen were significantly different in developed management zones except poor and very poor zones. The significant positive correlations of HCP and PRP with soil properties and fruit yield suggested that the ground conductivity data can be used to develop management zones for site-specific fertilization.