Articles
Response of northern highbush blueberry to fertigation and granular applications of phosphorus fertilizer
Article number
1357_8
Pages
51 – 58
Language
English
Abstract
Previous studies indicated that fertigating with N was more effective than using granular N fertilizers in northern highbush blueberry (Vaccinium corymbosum L.). The objective of the present study was to build on these findings and determine whether fertigation was also an effective method for applying P. The trial was located in Oregon, USA and conducted in a mature planting of Duke’ and Bluecrop’ blueberry.
Treatments were applied for 2 years to both cultivars and included no P, a single application of P fertilizer in the spring (early April) using granular monoammonium phosphate (MAP) at the highest recommended rate of 67 kg ha-1 P2O5, and weekly fertigation from late-April to late-July with liquid ammonium polyphosphate at a total rate of 34 or 67 kg ha-1 P2O5 year-1. Each treatment was also fertilized with 224 kg ha-1 N and 1.5 kg ha-1 B year-1. In the year prior to applying the P treatments, the concentration of P in recently expanded leaves was low in both cultivars (0.08-0.09%) and below the recommended level for blueberry in the region (>0.10%). Fertigation and granular applications of P fertilizer increased the concentration of P in soil solution within the root zone, but neither had any effect on yield, berry weight, or berry firmness during the study in either cultivar.
These treatments also had no effect on leaf P. In fact, the concentration of P in the leaves was no different than it was prior to applying any P to the plants.
The soil at the site was high in clay (Malabon series) and likely bound much of the P applied as fertilizer.
Similar results were found in grower fields in Oregon.
Questions remain on whether blueberry requires less P than recommended or if alternative sources or rates of P fertilizer are needed.
Treatments were applied for 2 years to both cultivars and included no P, a single application of P fertilizer in the spring (early April) using granular monoammonium phosphate (MAP) at the highest recommended rate of 67 kg ha-1 P2O5, and weekly fertigation from late-April to late-July with liquid ammonium polyphosphate at a total rate of 34 or 67 kg ha-1 P2O5 year-1. Each treatment was also fertilized with 224 kg ha-1 N and 1.5 kg ha-1 B year-1. In the year prior to applying the P treatments, the concentration of P in recently expanded leaves was low in both cultivars (0.08-0.09%) and below the recommended level for blueberry in the region (>0.10%). Fertigation and granular applications of P fertilizer increased the concentration of P in soil solution within the root zone, but neither had any effect on yield, berry weight, or berry firmness during the study in either cultivar.
These treatments also had no effect on leaf P. In fact, the concentration of P in the leaves was no different than it was prior to applying any P to the plants.
The soil at the site was high in clay (Malabon series) and likely bound much of the P applied as fertilizer.
Similar results were found in grower fields in Oregon.
Questions remain on whether blueberry requires less P than recommended or if alternative sources or rates of P fertilizer are needed.
Publication
Authors
D.P. Leon-Chang, D.R. Bryla, C.F. Scagel
Keywords
fruit quality, plant nutrition, soil nutrients, Vaccinium corymbosum, yield
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