EVOLUTION OF IRRIGATION METHODS: THE CASE OF APULIA REGION

In this paper the evolution of irrigation methods, in relation to socio-economic and technological developments, with particular reference to the territory of the Apulian region, are reported. The evolution of irrigation methods was determined not only by the need to reduce water consumption, but also to irrigation management at the farm level, such as: - the gradual increase in the cost of labor; - the growing decrease in the labor supply, even during the day. In the fifties of the last century, irrigation was performed with gravitational methods, while in the following decades it has gone progressively towards sprinklers and low pressure localized methods. The transition from gravitational irrigation methods to sprinkler and localized low pressure methods, water distribution was also aided by the evolution of the public water supply network. In fact the water distribution network changed from the free surface (channels) to pressure pipes, and the type of water delivery, both rounded or on demand, according to the needs of the crops. Now water networks begin to be realized equipped also with hydrants that, use magnetic cards (AcquaCard) showing contractual obligations. Water pipe networks delivery and the prevalence of autonomous water sources (private wells) have encouraged the spread of automation in irrigation management. However, the drilling of a large number of wells, on one hand has encouraged the expansion of irrigated areas and the spread of automated irrigation methods, on the other is leading to excessive pumping of water from aquifers, resulting in their progressive salinization, as occurs along the Adriatic coast. The evolution of irrigation methods, however, has relatively little contributed to contain specific seasonal irrigation volumes, so the future challenge will be to make the use of the current irrigation methods more efficient, through a correct definition of the irrigation variables (watering volumes and irrigation time) , in relation to: - the hydrological characteristics of the soil; - crops water needs; - the criterion of maximum cost-effectiveness of water use. Research institutions are focusing their actions on these issues and are already available information to be transferred in practice to promote water conservation. To make those information more usable in practice, however, it would be desirable the strengthening of technical support in agriculture.