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 agriculturalproduction. The aim of this study is to identify crop adaptation options to face the expectedchanges in water availability by exploiting the existing intra-specific biodiversity of thetomato crop and accounting for irrigation management and the hydrological properties ofsoils. The biophysical dimension of crop adaptation is therefore addressed. A study ispresented examining an irrigated district in southern Italy. Using as a climatic referencethe period 1961e90 and as a future climate the period 2021e2050, a soil water availabilityindicator was determined by a soil water balance model, at optimal irrigation and atdifferent deficit irrigation strategies, in 23 soil units. For five tomato cultivars, hydrologicalrequirements were determined by means of yield response functions to soil water availability.Cultivar-specific hydrological requirements were evaluated against the soil wateravailability indicator to determine probabilities of adaptation of each cultivar. These cultivarsare not currently being grown in the study area so their potential spatial distributionin the study area was estimated. For instance, with 60% of optimal irrigation, two cultivarswere assessed as having probabilities of crop adaptation larger than 0.89, in 90% and 62% ofthe area. In the future climate, with limited water resources, a proper choice and combinationof cultivars, irrigation strategies and soils would allow to maintain the currentproduction system in a large part of the study area.