A study led by the RAMA Group addresses the difficult question of how much to irrigate almond trees -

This study, led by RAMA Group researcher José Manuel Mirás Avalos, from the Center for Agri-Food Research and Technology of Aragón (CITA), has assessed, based on a meta-analysis of deficit irrigation trials in almond trees, the optimum water levels to be applied to maximize the efficiency of this crop. The study was carried out in collaboration with researchers from the Desertification Research Center (CIDE-CSIC), the Institute of Sustainable Agriculture (IAS-CSIC), the University of Seville, the Provincial Technic Agronomic Institute of Albacete (ITAP) and the Andalusian Institute of Agricultural Research and Training, Fisheries, Food and Organic Production (IFAPA).

The article, published in Agricultural Water Management, shows that, under semi-arid Mediterranean conditions in Spain, an application of 1,000 millimeters of irrigation or rainwater produces the highest almond yield, with about 2,500 kilograms per hectare.

The study has analyzed two irrigation strategies in almond trees: on the one hand, sustained deficit irrigation, with a continuous level of water restriction throughout the season; and, on the other hand, regulated deficit irrigation, in which water stress only occurs during certain periods of the crop cycle. The authors conclude that, in a situation of moderate water stress, regulated deficit irrigation is more beneficial for almond trees than sustained deficit.

This research is useful for establishing sustainable irrigation protocols, and farmers can use the results obtained to know what irrigation allocations they would have to apply to maximize yield and to know the response of the almond tree depending on the water deficit. In addition, water managers in the different Spanish river basins can use these results to optimize the management of water allocations that can be released to irrigation communities and make a better balance of the existing water demand in the basin.

The full study can be downloaded free of charge from the Agricultural Water Management journal website: https://doi.org/10.1016/j.agwat.2023.108208