Resumo

TREZZA, Ricardo et al. Daily water balance for sugarcane irrigation scheduling in a semiarid region in Venezuela by using the FAO-56 methodology. Bioagro [online]. 2008, vol.20, n.1, pp.21-27. ISSN 1316-3361.

To optimize the water use efficiency of sugarcane (Saccharum officinarum) grown under sprinkle irrigation in the semiarid region of Lara State, Venezuela, an irrigation program was scheduled based on the daily water balance in the root zone. The FAO-56 methodology was applied for the determination of the crop evapotranspiration and daily water balance. The results showed that the current operation of the irrigation system in the area, which consists in water application by using a fixed irrigation interval and a fixed irrigation depth, generates deep percolation losses in the early growing stages, as well as irrigation deficits in the crop maximum demand periods that would produce a reduction on the crop yields. In this study an alternative management of the irrigation scheduling is proposed considering the same fixed irrigation interval but a variable irrigation depth defined as the water depletion in the root zone.

Palavras-chave : Evapotranspiration; Penman-Monteith equation; Saccharum officinarum.