Effects of irrigation of highbush bluberry cultivaed on sandy soil

Field experiment was done in Agriculture Experiment Station Lipki near Szczecin. As objects of studies were 1, 8, 9 and 10 years old blueberry plants cul-tivated on the acid brown soil belong to good rye complex. Before planting be-tween the rows of plants 10 cm layer of sawdust obtained from coniferous trees was spread and mixed with the soil. Growth and yielding of two varieties ‘Spartan’ and ‘Patriot’ irrigated and not irrigated. Plants were irrigated using dropping lines with emitters collocated every 30 cm with total efficiency of 2,4 l.h-1. Tensiometers show the need of irri-gation. Field and plants were irrigated when soil suction power was bigger than 0,01 MPa. Every year blueberry plants were fertilized with 60 kg N.ha-1 and doses of P and K depended on their concentration in soil. Total doses of water used for irrigation depended on yearly precipitation equal in 2005y. – 128 mm, 2006y. – 300 mm, 2007y. – 400 mm and in 2008y. – 200mm. Blueberry cv. ‘Spartan’ was more productive (9,62 t.ha-1) than ‘Patriot’ (8,3 t.ha-1). As effect of supplemental irrigation average crop of ‘Patriot’ variety increased by 8,36 t.ha-1 and ‘Spartan’ by 7,94 t.ha-1. Weight of 1000 fruits ...