Gypsum—An Alternative to Chemical Fertilizers in Lowbush Blueberry Production

SUMMARY Five experimental trials were established in commercial lowbush blueberry (Vaccinium angustifolium Ait.) fields in eastern Canada and monitored over two cropping cycles to determine the value of gypsum as a soil amendment. Lowbush blueberry plants were treated each cropping cycle with either: (1) no application (control), (2) 10-10-10 fertilizer applied at 300 kg/ha (268 lb/acre), (3) gypsum applied at 4 t/ha (3572 lb/acre), or (4) the combination of (2) and (3). In the first cropping cycle, the application of gypsum and gypsum with fertilizer significantly increased tissue concentrations of N, P, K, Ca, Mn, and S in comparison to the control and fertilizer only treatments. Tissue K, Ca, Mn, and S were significantly increased in the second cropping cycle with gypsum application. Soil pH was reduced in the second cropping cycle with gypsum application. Gypsum with fertilizer increased stem length, live buds, total buds, and total blossoms in the first cropping cycle in comparison to the control. The treatments had no significant effect on marketable yield.