Irrigating sugar beet by means of a decision support system in Italy

An irrigation software has been developed for the sugar beet crop, which calculates a water balance based on the Hargreaves equation, with reduced Kc’s compared to reference sources, and considering the contribution from the shallow water-table. It was validated in field trials over two years in North-Central Italy, where it showed an ability to simulate crop water consumptions, with a slight tendency to under-estimate soil-moisture depletion, which in turn did not hamper yield potential. A further reduction (50%) of irrigation volumes, with respect to those indicated by the software, did not prove effective in enhancing sugar yield and irrigation convenience. Four irrigation systems were also compared, that resulted equivalent in raising yield. In the not-so-dry environment of the trials, the two fixed systems, drip irrigation and fixed mini-sprinklers, were quite un-economical vs. a rainfed control, while the two mobile ones, travelling gun and boom, achieved a consistent advantage in terms of net profit over the rainfed crop.