Root System of Olive Trees ( Olea Europaed L.) Based on Runoff Harvesting System During Dry Period

This paper presents a study of a field trial experiment at olive orchard irrigated by runoff harvesting system under a dry climate which was carried out on 5-year-old olive trees (Olea europaea. L, cv. Barnea) in the middle of Negev desert, starting right after the floods, onwards during the summer growing season. The beginning of the experiment occurred after 2 years with little rain and no run-off events. The olive trees were under severe drought stress when we first initiated controlled flooding in 2017. In the second research year (2018), a massive natural flood had occurred at the end of April. Results show that the water distribution within the soil was highly inhomogeneous even under flood conditions. Soil water loss rate, due to transpiration was mainly correlated with the total amount of soil water and not atmospheric conditions. The relative root water uptake from shallow soil layers (0.3-1.5m) gradually reduced along the season, while the relative water uptake from the deeper layers (1.5-4m) became more pronounced.