Irrigation requirement for Eucalyptus pellita during initial growth

Abstract

The growth of Eucalyptus pellita in forestry plantations requires attention to water requirements, especially in the initial growth phase from seedling to field-ready plant. In this study, actual evapotranspiration (ETa), crop coefficient (Kc), and the irrigation requirement of E. pellita were assessed during the nursery growth phase (day 40-142). The experimental set-up included lysimeters with different treatments in terms of plants, drainage, and soil conditions. Plant growth and water balance were monitored during June September 2018 in an open nursery area in Riau, Indonesia. ETa was determined by the water balance lysimeter method and potential (reference) evapotranspiration (ETo) was extracted based on the Penman-Monteith method (FAO/56). The results showed that the average Kc value for E. pellita at age 40-142 days is 0.79, which exceeds that reported for E. grandis. The recommended irrigation requirement varies depending on precipitation, from 70 mL/plant/day with no rainfall to zero at precipitation of > 30 mm/day. This is the first study to assess water use in E. pellita growing in pots during the nursery phase, which provides guidance on irrigation requirements during their initial growth phase.