Adaptability to future climate of irrigated crops: The interplay of water management and cultivars responses. A case study on tomato

In the context of climate change strategies are needed towards sustainable agricultural production. The aim of this study is to identify crop adaptation options to face the expected changes in water availability by exploiting the existing intra-specific biodiversity of the tomato crop and accounting for irrigation management and the hydrological properties of soils. The biophysical dimension of crop adaptation is therefore addressed. A study is presented examining an irrigated district in southern Italy. Using as a climatic reference the period 1961e90 and as a future climate the period 2021e2050, a soil water availability indicator was determined by a soil water balance model, at optimal irrigation and at different deficit irrigation strategies, in 23 soil units. For five tomato cultivars, hydrological requirements were determined by means of yield response functions to soil water availability. Cultivar-specific hydrological requirements were evaluated against the soil water availability indicator to determine probabilities of adaptation of each cultivar. These cultivars are not currently being grown in the study area so their potential spatial distribution in the study area was estimated. For instance, with 60% of optimal irrigation, two cultivars were assessed as having probabilities of crop adaptation larger than 0.89, in 90% and 62% of the area. In the future climate, with limited water resources, a proper choice and combination of cultivars, irrigation strategies and soils would allow to maintain the current production system in a large part of the study area.