Irrigation Patterns and Scheduling of a Telecontrolled Irrigation District in Northeastern Spain

Abstract

Over the last 10 years, telecontrol systems have been incorporated into the majority of modern collective pressurized irrigation networks in Spain. This type of infrastructure provides many opportunities for irrigation management but actually, in Spain, is only used for standardized network operations. The Candasnos irrigation district (CID), located in northeastern Spain, is equipped with this system, and contains a variety of different pressurized systems. Telecontrol data and crop water requirements were used to analyze the evolution of irrigation performance (SIPI) of maize, alfalfa, and stone fruits. Irrigation guidelines for stone fruit were analyzed and compared with those of standard and regulated deficit irrigation (RDI) irrigation strategies. Ten solid-set irrigation systems were monitored to determine on-farm irrigation patterns. The average SIPI of maize, alfalfa, and peach was 83, 107, and 123%, respectively. The average SIPI showed a high irrigation performance, but the spatial and temporal variability of SIPI showed possibilities for improvement. Deficit irrigation practices were conducted on peach trees but not adjusted to the recommended RDI strategy. The results of plot monitoring showed crop differences on irrigation time per event (1–1.5 h in maize and 2–3 h in alfalfa) and on time interval between irrigation (larger in alfalfa than in maize). The short and frequent irrigation timing for the corn crop could be a disadvantageous practice because it yielded high evaporation losses from crop-intercepted water. Two irrigation patterns were established at the CID: the first was characterized by structured irrigation schedules and the second was characterized by weekly changes in the irrigation schedule. The second pattern was more commonly employed in solid-set systems than in those with pivots. The analysis of telecontrol data following this methodology could be easily implemented in the daily routines of the district office to improve irrigation management at the plot level. Further, telecontrol data can be an important tool for promoting and facilitating regulated deficit irrigation strategies in stone fruits.