Evapotranspiration in Sudan grass second culture grown under non – irrigated and optimal irrigated conditions

Abstract

Abstract: The aim of the present study was to establish the evapotranspiration of Sudan grass variety Engje-1, grown as a second crop for silage on meadow-cinnamon soil for the region of Southern Bulgaria under irrigation conditions and without irrigation. For this purpose, an experiment with Sudan variety Endje-1 was conducted in the experimental field of the Agricultural Institute – Stara Zagora on soil type meadow-cinnamon soil, after its predecessor barley. The Sudan grass is harvested in the brooming stage. Two variants were explored: Variant 1 – without irrigation (control) and Variant 2 – with optimal irrigation, 70-75% of field capacity (FC). Evapotranspiration of Sudan grass grown as a second crop under non-irrigated conditions, depending on the nature of the year, ranges from 168.7 mm to 183.7 mm. Under conditions of irrigation, the largest share in the formation of the water consumption is occupied by the irrigation norm – 87.1% on average (from 86.3 to 90.8%). Under irrigated conditions, the relative participation of the initial water reserve in the formation of evapotranspiration significantly decreases.

Keywords

• field capacity
• irrigation norm
• irrigation depth
• precipitations
• water balance
• water consumption