Agricultural Water Management 196 (2018) 1–14
Agro-industrialwastewaterreuseforirrigationofavegetablecropsuccession under Mediterraneanconditions
Angela Libuttia,∗, Giuseppe Gattaa, Anna Gagliardia, Pompilio Vergineb, Alﬁeri Polliceb,
Luciano Beneducea, Grazia Disciglioa, Emanuele Tarantinoa
a Department of Science of Agriculture, Food and Environment, University of Foggia, Italy
b IRSA CNR, Viale F. De Blasio, 5-70132 Bari, Italy
ar t iclein foabstract
Received 23 February 2017
Received in revised form 9 October 2017 Accepted 16 October 2017
Available online 20 October 2017
Agro-industrialwastewater Wastewater reclamation Wastewaterreuse
Soil contamination Crop yieldquality
In many countries of the Mediterranean region, characterized by frequent drought periods, agricultural production often occurs under water deﬁciency or conditions that cause the depletion of the existing water resources. In these areas, the reuse of reclaimed wastewater for crop irrigation could contributeto mitigate/decrease water shortage, support the agriculture sector and protect groundwater resources. In 1.5-year ﬁeld experiments in Southern Italy (Apulia Region), the effects of irrigation with treated agro-industrial wastewater on soil properties, crops yield and qualitative traits of crop products, includ- ing their microbiological safety, were assessed. Groundwater (GW), secondary treated wastewater (SW) and tertiary treated wastewater (TW) from an innovative “on-demand” UV disinfection system wereused to irrigate tomato and broccoli, cultivated in succession. The three irrigation water sources and the corresponding irrigated soils, plants and crop products were analyzed for the main physico-chemical characteristics, quali-quantitative parameters and fecal indicators. SW and TW showed higher values of the main physico-chemical parameters than GW. SW irrigated soil resulted in a signiﬁcant increase of NH4-N,Na+,SAR,EC(belowthethresholdvaluebeyondwhichasoilisdeﬁnedassaline)duringtheﬁrst tomato crop cycle, and of pH during the broccoli growing season. Irrigation with treated wastewaterdid not signiﬁcantly affect the marketable yield nor the qualitative traits of tomato and broccoli crops, except for the Na+ and NO3− content (below the threshold levels deﬁned by the European guidelines for vegetables). High levels of E. coli (above the Italian limit for reuse), Fecal coliforms and Fecal enterococci (up to 104 CFU 100 ml−1) were observed in the SW and, when chlorination was not done, in the TW. Nevertheless,E.coli wasnotisolatedfromanysampleofsoil,plantandcropproduct,probablyduetoits rapiddie-off.Moreover,lowconcentrationsofFecalcoliformsandTotalheterotrophiccountwerefoundin plant and crop product. The drip irrigation system used, which avoided the close contact between water and plant, may have contributed to this. Under the conditions applied in this study, the reuse of treated agro-industrial wastewater for irrigation can be considered an effective way to cope with agricultural water shortage in the Mediterraneanarea.
© 2017 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
AnumberofMediterraneancountriessufferfromwaterscarcity, which has become severe in recent years due to global climate changecausingfrequentandlonglastingperiodsofdrought.Par- ticularly during the summer, these areas experience severewater supply and demand imbalances. In the last decades, many Ital- ianregionshavefacedthenegativeimpactofdroughtandthe
∗ Corresponding author.
E-mail address: firstname.lastname@example.org (A. Libutti).
resourcescarcityhasmostlypenalizedagriculturalactivities,which uses more than 50% of the total available water, while other high priority demands, such as those from civil and industrialsectors, are satisﬁed (Coppola et al., 2004). Particularly, in Apulia Region (South-Eastern Italy), water shortage has a serious impact on the localeconomy,mostlybasedonagriculture.Moreover,theagricul- turalcoastalareasofApuliaRegionsufferfromrelevantphenomena of seawater intrusion into the water table, due to the excessive and often uncontrolled groundwater withdrawals for irrigation (LibuttiandMonteleone,2012).Forthesereasons,alternativewater sources areneeded.
Treated municipal wastewater is the most readily available source of water to meet the increasing demand for crop irriga- tion. Indeed, in recent years, wastewater recycling in agriculture hasgainedimportanceascomponentofagriculturalwatersupply inseveralwater-scarcecountries(Qadiretal.,2007;Pedreroetal.,2010). Wastewater reuse not only provides signiﬁcant amount of irrigationwater,butalsocontributestoconservepotableresources andreducestheenvironmentalimpactrelatedtotheefﬂuentsdis- charge into water bodies (Aiello et al., 2007; Pedrero et al., 2010;AgraﬁotiandDiamadopoulos,2012).Furthermore,soilapplication of treated wastewater also constitutes a reliable source of nutri- ents(especiallynitrogen,phosphorusandpotassium)andorganic matter useful for maintaining the fertility and the productivityof the soil (Meli et al., 2002; Rusan et al., 2007). Treated wastewater useforcropirrigationcanimprovegrowthandyieldofherbaceous species (Kiziloglu et al., 2008; Bedbabis et al., 2010) and can also enhance the economic beneﬁts for farmers, due to reduced need for fertilizer (Bedbabis et al., 2010; Paranychianakis et al., 2006).However,thechemicalcompositionofwastewaterhastobemon- itoredtoavoidimbalanceinnutrientsupply,whichmayresultin excessivevegetativegrowth,unevenfruitmaturity,reducedqual- ityandquantityofyields(Pedreroetal.,2010).Treatedwastewater should be used for irrigation under controlled conditions, also to minimizehazardstoagriculturalproducts,soilandgroundwater fromtoxicandpathogeniccontaminants(Aielloetal.,2007;Qadiretal.,2007).Wastewatermaycontainavarietyofpollutants,such as salts, heavy metals, organic compounds, enteric bacteria and viruses. An excessive accumulation of trace metals, such as Cd, Cu,Fe,Mn,PbandZn,insoilsthroughirrigationcreatesproblems for agricultural production (Singh et al., 2004) and leads to metal uptake by crops, so affecting food quality and safety (Khan etal.,2008).Oneofthecrucialissuesinthereuseoftreatedwastewater forcropirrigationistheresidualpresenceofpathogenicmicroor- ganism (Rubino and Lonigro, 2008; Petterson et al., 2011) which representsapotentialhealthrisktoconsumerswhentheyenterin thefoodchain(Toze,2006).InItaly,therearestrictregulationsfor reclaimed wastewater reuse (Decree No. 152, 2006, Ministry for Environment), especially for levels of some chemicalcompounds andformicrobialparameters.Withregardtomicrobiologicalcon- taminationlevels,thecorrespondingguidelinesallowunrestricted cropirrigationwithabacteriologicalefﬂuentqualitycharacterized bylessthan10CFU100ml−1ofE.coliin80%ofsamples.
yieldofreclaimedurbanwastewaterapplicationforvegetableand fruit crops irrigation in the Mediterranean area (Lonigroet al.,2007; Palese et al., 2009; Disciglio et al., 2014; Lonigro et al., 2015;Gattaetal.,2016).Our