Abstract
Experiments were conducted in lysimeters with sandy soil under an automatic rain-out shelter to study the effects of subsurface drip irrigation treatments, full irrigation (FI), deficit irrigation (DI) and partial root-zone drying (PRD), on nitrogen (N) dynamics in the soil-plant system of potatoes. In 2005, FI and PRD 2 were investigated, where FI plants received 100% of evaporative demands, while PRD 2 plants received 70% water of FI at each irrigation event after tuber initiation. In 2006, besides FI and PRD 2 treatments, DI and PRD 1 receiving 70% water of FI during the whole season were also studied. Crop N uptake and residual NH 4-N and NO 3-N to a depth of 0–50 cm, at 10 cm intervals were analyzed. For both years, the PRD 2 treatment resulted in 30% water saving and maintained yield as compared with the FI treatment, while when investigated in 2006 only, DI and PRD 1 treatments resulted in significant ( P < 0.05) yield reductions. In 2005, the soil residual N content at harvest was significantly 29% lower with PRD 2 than for FI in the whole root zone; and leaf N concentration for PRD 2 was significantly higher than for FI. In 2006, soil residual N content at harvest was 33% lower with PRD 2 than for FI, which was not significant however. In the late season, reflectance vegetation index and leaf area index for the water saving treatments were higher than for the FI treatment. For both years the PRD 2 treatment had the lowest residual N content in the root zone. We conclude that: (1) of the investigated water saving irrigation strategies (PRD 1 PRD 2, DI) PRD imposed just after tuber initiation until maturity (PRD 2) was the only strategy able to maintain yield; thus, soil drying induced by PRD or DI treatments should be avoided during early growth stages; (2) the PRD and DI treatments improved soil nitrogen availability late in the growing season maintaining top ‘greenness’ to a greater extent, as compared with FI.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
