Partial root-zone drying increases WUE, N and antioxidant content in field potatoes

Partial root-zone drying (PRD) is a new water-saving irrigation strategy which requires that the roots are simultaneously exposed to both dry and wet soil zones. This technique is now undergoing extensive trials with a range of agricultural crops. These results show significant benefit in increasing water-use efficiency. The field potato (Solanum tuberosum L. cv Liseta) experiments were conducted during 2007 and 2008. Subsurface drip irrigation was used. In 2007 season PRD plants received 70% of full irrigation (FI). To further enhance water saving during the last 3 weeks of the irrigation period, PRD using 70% of FI was replaced with PRD using 50% of FI in 2008. By five harvests during the season N content, fresh and dry matter (DM) of leaves, stems and tubers were followed. At final harvest the effects of PRD and FI irrigation on total and marketable yield and yield quality were investigated. Also, the irrigation water-use efficiency (IWUE) was calculated. As compared to FI, PRD treatment saved 33% (2007) and 42% (2008) of irrigation water while maintaining similar yield. This resulted in 38% and 61% increase in IWUE for the 2007 and 2008 seasons, respectively. In both years the PRD treatments resulted in the increase of N, starch content and antioxidant activity in potato tubers. The latter novel findings on the effect of PRD irrigation on tubers quality might be favorable for the health-promoting potato value.