EVAPOTRANSPIRATION-BASED IRRIGATION SCHEDULING FOR PICEA ABIES (SPRUCE) SEEDLINGS

Abstract

The water balance of agro ecological systems is a key parameter for most physical and physiological processes with the system soil–crop–climate. Therefore it is of great importance to calculate the water budget parameters in the required scale. The field study was conducted in the period of 2002–2005. Seedlings were planted in Irrigation engineering department experimental fields at the Lithuanian University of Agriculture. Seedlings were grown under standard nursery cultural practices until being transplanted into new fields in mid April 2002 and 2004. The research site contains evaporators and 8 lysimeters in which spruce seedlings were grown and studied. Lysimeters amount 42 m² and 30 m².
At 2002, field No.1 was irrigated 8 times, irrigation norm was 250 m³ ha^-1 and seedling got 2000 m³ ha^-1  water. Field No.2 was irrigated 6 times, irrigation norm – 1500 m³ ha^-1. In 2003 fields No. 1 and No. 2 were irrigated 4 times and seedlings got 1000 m³ ha^-1  water. At 2004, field No.1 was irrigated 8 times, irrigation norm was 250 m³ ha^-1  and seedling got 2000 m³ ha^-1  water. Field No.2 was irrigated 6 irrigation norm – 1500 m³ ha^-1.
The total evapotranspiration of the first year seedlings planted in the field No.1 in 2004 made up 323 mm. The total evapotranspiration of the seedlings growing in variant No. 2 was 307 mm in 2004 and it is by 16 mm less as compared to variant No.1.

 Keywords: irrigation, evapotranspiration, picea abies seedlings.

 Article DOI: http://doi.org/10.15544/RD.2015.062