Effects of Irrigation Depth on Soil Water Availability and Vegetative Growth of Apricot Nursery Plants Under Sustainable Irrigation Management

This study evaluated the effect of different irrigation depths on soil water availability and vegetative growth of apricot ( Prunus armeniaca L.) nursery plants under open-field conditions in northwestern Romania during the 2024 growing season. Two cultivars (‘Excelsior’ and ‘Favorit’) grafted on Prunus cerasifera were subjected to four irrigation regimes (0, 10, 20, and 30 mm per event). Soil moisture was monitored using tensiometers, and vegetative growth was assessed as total branch length. Results showed that irrigation significantly influenced soil water availability, especially during dry periods. Irrigated treatments maintained higher soil moisture compared to rainfed conditions. However, moderate irrigation levels (10–20 mm) produced vegetative growth comparable to higher irrigation (30 mm), indicating limited benefits of increasing irrigation depth beyond moderate levels. The Lp-norm index supported these findings by showing only small gains in integrated irrigation-growth performance at higher irrigation inputs. The study suggests that moderate irrigation can sustain vegetative growth in apricot nursery plants while reducing water use. These findings support the development of more efficient irrigation strategies, although results should be interpreted with caution as they are based on a single growing season.