Soil water dynamics and olive yield (Olea europaea L.) under different surface drip irrigation treatments in northern Mediterranean

The use of modern irrigation systems and monitoring of soil water status can help improve crop performance and water use efficiency. The influence of different irrigation treatments on soil water content dynamics and olive oil yield was studied over two growing seasons using a surface drip irrigation system in an olive grove in northern Mediterranean climate. Irrigation treatments included optimal irrigation, sustained deficit irrigation (33 % of optimal irrigation), and rainfed treatment. Based on the water applied, we calculated the percentage of replenished estimated evapotranspiration (ETc*) for each treatment using the Penman-Monteith method. Soil water content dynamics were monitored with capacitive probes at five depths (10 to 50 cm). The increase in soil water content at a depth of 30 to 50 cm, which was only achieved with optimal irrigation, resulted in a significantly higher olive oil yield. In contrast, deficit irrigation, despite the addition of water, did not lead to an increase in soil water in the layers below 30 cm, so that the yield was equal to that of rainfed treatment. In irrigated olive groves, it is beneficial to monitor the water content of the soil at several depths to ensure that a sufficient amount of water has been applied.