Respuesta del olivo a estrategias de riego que varían el volumen del suelo humedecido

The alternate partial root watering (RPA) is a deficit irrigation technique developed on vine in the nineties decade. Its advantages have been postulated as water saving and growth control while maintaining high rates of stomatal conductance (gs) and photosynthesis (A). One aspect that has not been evaluated is the effect of this technique on water conductance of the soil-plant system (CHs-p). We present the results of a trial of three years old Olea europaea L. trees cv. Arbequina with the radically system divided into two pots to appraise the effect of RPA on the CHs-p, gs and A, contrasted with trees under a Fixed Partial Irrigation (RPF), and Total Irrigation (RT); all of them have been irrigated with the same amount of water. The tests were conducted under conditions of high and low ambient evaporative demand (ETo). We also analyzed the response of CHS.* to the volume change in wet soil in RPF and in drying soil process. The results showed a significant drop in CHs-p 45 per cent in RPA and 49 per cent in RPF in respect of RT under high evaporative demand, while the decrease was 45 per cent in RPA and 39 per cent in RPF in respect of RT in low evaporative demand. No significant differences were observed between RPA and RPF. When analyzing the CHs-p per unit root length (CHulr) present in each pot, the highest CHulr values were obtained in the treatment of RPF. No significant differences were observed in gs and A in RPA respect of RPF and RT. On the other hand, there was no significant response CHs-p to the volume change under irrigation, which was attributed to the conditions of high humidity and low ETo. When analyzing the CHs-p under a drying cycle, there was a significant drop in CHs-p, gs and A. The conclusion is that the RPA does not improve the CHs-p in olive trees.