Effects of gypsum on yield and nutrient status of native lowbush blueberry

Abstract

Information is required on the response of native lowbush blueberry (Vaccinium angustifolium Ait.) to soil-applied calcium amendments. Field experiments were carried out in Prince Edward Island to determine the effects of applied gypsum, as a Ca source, on yield and leaf nutrient content of native lowbush blueberry at six sites, two locations per year. Sites were studied over several cropping cycles. Gypsum applied at 2, 4, 6, and 8 t ha−1 in the spring of the sprout year increased marketable yield (from 3.2 to 4.7 t ha−1) at three of six sites in the first crop year following application of gypsum. Averaged over these three sites, marketable yield was increased 47% by the application of gypsum at 4.0 t ha−1. Yield was not affected in the second and third cropping cycles. Mean berry weight and plant growth were not affected by gypsum application. Concentration of leaf Ca was increased but not consistently significant, while leaf S was significantly increased at all sites in the first cropping cycle. Soil pH was significantly reduced by gypsum in the first cropping cycle. A yield increase of 225 kg ha−1 would be sufficient to recover the costs of the applied gypsum. Key words: Gypsum, leaf nutrient concentration, lowbush blueberry, Vaccinium angustifolium Ait., yield