Influence of mulching and nitrogen fertilization rate on growth and yield of highbush blueberry.

摘要

The aim of this experiment was to study the influence of different ways of mulching and nitrogen (N) fertilization rate on growth and yield of highbush blueberry, cv. Bluecrop. This experiment was set up in spring 1999 in Skierniewice, central Poland. Plants were established on a mineral podsolic soil with 17% clay and silt, at a planting density of 2.0x1.0 m. The following soil treatments in the rows were included: soil without any mulching (control); soil mulched with sawdust; soil mulched with bark; soil mixed with sawdust and mulched with sawdust; and soil mixed with bark and mulched with bark. In addition, each spring four different N fertilization rates (0, 60, 120 and 180 kg N/ha) and in autumn potassium and phosphorus rates (90 kg K and 25 kg P/ha) were applied. Pruning of plants was limited to removing damaged shoots. During three years of the experiment (2001-03) the longest one-year-old shoots were obtained from the combination of sawdust mixed with soil or mulched. Plants from the control plots and mulched with bark had the smallest number and the shortest shoots. The sawdust had more of a positive influence on plant yield than bark. Nitrogen fertilization rates higher than 60 kg N/ha decreased yield, except for the plots mulched with bark. Fruit size was more influenced by yield than by N fertilization or mulching..