Agricultural Water Management 131 (2014) 30–40 Contents lists available at ScienceDirect Agricultural Water Management j ourna l h o me pa ge: www.elsevier.com/locate/agwat Substrate water status and evapotranspiration irrigation scheduling in heterogenous container nursery crops Luca Incrocci a,∗ , Paolo Marzialetti b , Giorgio Incrocci a , Andrea Di Vita a , Jos Balendonck c , Carlo Bibbiani d , Serafino Spagnol e , Alberto Pardossi a a Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy b Experimental Station for Nursery Crops (Centro Sperimentale per il Vivaismo, Ce.Spe.Vi.), Pistoia, Italy c Wageningen UR Greenhouse Horticulture, Wageningen, The Netherlands d Department of Veterinary Science, University of Pisa, Pisa, Italy e Spagnol Greenhouse Technology Ltd., Vidor, Treviso, Italy a r t i c l e i n f o Article history: Received 28 March 2013 Accepted 12 September 2013 Keywords: Crop coefficient Evapotranspiration model Hardy ornamental nursery stocks Nutrient emission Soil moisture sensor Water runoff a b s t r a c t A study was conducted to determine the effects of implementing different irrigation scheduling meth- ods on heterogeneous container hardy ornamental nursery stocks. Four ornamental shrub species were grown in the same irrigation sector during the summer of four consecutive years (2007–2010): Forsythia × intermedia, Photinia × fraseri, Prunus laurocerasus L. and Viburnum tinus L. Automated drip irrigation based on either substrate water status (SW) or calculated crop evapotranspiration (ET; MODEL) was compared with “typical” timer-controlled irrigation (TIMER). In TIMER treatment, containers were irrigated based on grower management. In SW treatment, irrigation was controlled either by a water- filled tensiometer (2007) or by a dielectric soil moisture sensor (2008–2010) placed in one pot with a Prunus plant, the species with intermediate water need as found in preliminary work. In MODEL treat- ment, irrigation was controlled on the basis of the species with the greatest ET. Crop ET was calculated multiplying reference ET (ET 0 ) by a species-specific crop coefficient (K C ), which in turn was estimated from plant height. In all treatments, pre-irrigation substrate water deficit was lower than the plant available water in the container. Compared with TIMER treatment, SW and MODEL irrigation scheduling reduced considerably both water use (-21% to -40%) and nutrient emission (-39% to -74%) with no significant effect on plant growth and quality. Water saving resulted from a reduction of irrigation frequency and leaching fraction (water leached/water applied). Wireless sensor network technology and near/remote monitoring techniques can facilitate the application of plant-driven irrigation scheduling in commercial nurseries, where generally hundreds of plant taxa are cultivated in many independent irrigation sectors. © 2013 Published by Elsevier B.V. Introduction The production of hardy ornamental nursery stocks (HONS) is an important horticultural sector in several countries, such as the United States, The Netherlands and Italy (AIPH, 2011). In Europe, one of the major production centres is located around the town of Pistoia in Tuscany (Italy), where nearly 1500 nurseries are in operation on approximately 5200 ha (Nicese and Ferrini, 2009). In this area, container cultivation has been increasingly used in the last 10–15 years as it provides many advantages, such as fast plant ∗ Corresponding author at: Department of Agriculture, Food and Environment, University of Pisa, Viale delle Piagge 23, 56124 Pisa, Italy. Tel.: +39 050 2216 529; fax: +39 050 2216 524. E-mail addresses: luca.incrocci@unipi.it, luca.incrocci69@gmail.com (L. Incrocci). growth, year-round marketing and easy plantation establishment. The area covered by container crops is currently estimated to be around 1000 ha (Nicese and Ferrini, 2009). Water and nutrients are often applied in excess to nursery crops in Pistoia, with leaching fractions (LF = water leached/water applied) ranging from 30 to 50% (Marzialetti and Pardossi, 2003). This results in water wastage and environmental pollution due to the leaching of fertilisers and plant protection products (e.g. herbicides; ARPAT, 2007). Generally, overhead sprinkler irrigation is used for containers smaller than 5–7 L, and micro-irrigation systems (drip or micro-spray irrigation) for larger containers. Crops are irrigated from May to October, when rainfall is scarce or almost negligible, like for instance in 2003 and 2012. Sea- sonal irrigation volume ranges from 1000 m 3 ha -1 in soil-bound crops to 10,000–15,000 m 3 ha -1 in container crops (Marzialetti and Pardossi, 2003). These figures are similar to those reported for 0378-3774/$ – see front matter © 2013 Published by Elsevier B.V. http://dx.doi.org/10.1016/j.agwat.2013.09.004