Evaluation of zero-runoff irrigation systems for containerized nursery production

Water is a primary resource and its availability for ornamental industry will soon be reduced because of increasing costs and because of competition with other sectors. In addition, in nursery production a noteworthy amount of fertilizers is leached off in the environment with water, causing pollution of the superficial water bodies. Technologies able to rationalize both the irrigation and the fertilization, like closed-loop or capillary mat systems, are a possible solution to reduce both water use and fertilizer leaching. The aim of this study was to test different irrigation systems for nursery ornamental crops, analyzing also the problems linked to reuse of drained solutions. A traditional irrigation system (OI - overhead irrigation) was compared with two zero-runoff systems: A closed system (WR - overhead irrigation with recycling of runoff) and a sub-irrigation system with capillary mat (CM). For each system a 300 m 2 tunnel covered with an anti-hail net was used. About water consumption, CM allowed 26% water savings, while the WR system allowed the saving of 20% of the water. No differences in plant quality were observed among irrigation systems. In the zero-runoff systems economic and ecological benefits are clear. In particular, the system equipped with capillary mat showed the best performances.