Overhead Irrigation Saves Water Significantly in Commercial Potato Production in Florida

A trial was conducted on four private farms in Florida from 2012 to 2014 to determine water savings of converting seepage irrigation to center pivot irrigation for potato production. There were two irrigation treatments: seepage and center pivot with four replicates. Rain gauges and flowmeters were installed for both treatments on each of the farms to monitor rainfall and water usage. Soil moisture was also monitored by moisture sensors. The results showed that the average water usage was 338 ± 99 mm and 752 ± 175 mm for center pivot and seepage in the first growing season, respectively. Water savings of center pivot irrigation were 55% (4,136 m³/ha). In the second growing season which was wet, the corresponding average water usage was 193 ± 31 mm and 462 ± 145 mm. The water savings were 58.6% (2,716 m³/ha). Potato plants had greater leaf water potential and stronger tolerance to freeze damage with center pivot than with seepage. The tuber yields were 31.4 ± 2.0 and 33.4 ± 2.5 tons/ha for center pivot and seepage, respectively. The corresponding tuber yields in the second growing season were 42.3 ± 5.2 tons/ha and 46.5 ± 5.4 tons/ha. Seepage irrigation had higher soil nitrate contents and greater tuber yields as compared with center pivot irrigation. The results suggest that center pivot irrigation requires a new fertilize program. The overall water use efficiency (WUE) was 0.11 ± 0.05 and 0.05 ± 0.01 m³ per kg tubers for seepage and center pivot, respectively. The WUE was 2.2-fold greater with center pivot than with seepage. This water savings and greater WUE can significantly enhance the agricultural and environmental sustainability.