Controlling irrigation using timers or manually operated systems is the most common irrigation scheduling method in outdoor container production systems. Improving irrigation efficiency can be achieved by scheduling irrigation based on plant water needs and the appropriate use of sensors rather than relying on periodically adjusting irrigation volume based on perceived water needs. Substrate amendments such as biochar, a carbon (C)-rich by-product of pyrolysis or gasification, can increase the amount of available water and improve irrigation efficiency and plant growth. Previous work examined two on-demand irrigation schedules in controlled indoor (greenhouse) environments. The goal of this study was to evaluate the impact of these on-demand irrigation schedules and hardwood biochar on water use and biomass gain of container-grown Hydrangea paniculata ‘Silver Dollar’ in a typical outdoor nursery production environment. Eighteen independently controlled irrigation zones were designed to test three irrigation schedules on ‘Silver Dollar’ hydrangea grown in pine bark amended with 0% or 25% hardwood biochar. The three irrigation schedules were conventional irrigation and two on-demand schedules, which were based on substrate physical properties or plant physiology. Conventional irrigation delivered 1.8 cm water in one event each day. The scheduling of substrate-based irrigation was based on the soilless substrate moisture characteristic curve, applying water whenever the substrate water content corresponding to a substrate water potential of –10 kPa was reached. The plant-based irrigation schedule was based on a specific substrate moisture content derived from a previously defined relationship between substrate moisture content and photosynthetic rate, maintaining the volumetric water content (VWC) to support photosynthesis at 90% of the maximum predicted photosynthetic rate. Total water use for the substrate-based irrigation was the same as for the conventional system; the plant-based system used significantly less water. However, plant dry weight was 22% and 15% greater, water use efficiency (WUE) was 40% and 40% greater, and total leachate volume was 25% and 30% less for the substrate-based and plant-based irrigation scheduling systems, respectively, than for conventional irrigation. The 25% biochar amendment rate reduced leachate volume per irrigation event, and leaching fraction, but did not affect total water use or plant dry weight. This research demonstrated that on-demand irrigation scheduling that is plant based or substrate based could be an effective approach to increase WUE for container-grown nursery crops without affecting plant growth negatively.
This project was supported by Agriculture and Food Research Initiative Competitive Award no. 2015-68007-23212 from the U.S. Department of Agriculture (USDA) National Institute of Food and Agriculture.
We acknowledge the USDA National Institute of Food and Agriculture for financial support; and Proton Power, Lenoir City, TN for the biochar source. We gratefully acknowledge Dr. Jim Owen, Dr. Jeb Fields, Dr. Grace Pietsch, Galina Melnichenko, Lori Osborne, and Melanie Stewart for their contributions; Dr. Arnold Saxton for statistical analysis; and Dr. Daniel Yoder and Magdalena Pancerz for their careful review, which greatly enhanced this manuscript.
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Arguedas-RodriguezF.R.2009Calibrating capacitance sensors to estimate water content matric potential and electrical conductivity in soilless substrates. University of Maryland College Park MS Thesis
Basiri JahromiN.WalkerF.FulcherA.AltlandJ.2016Effect of biochar on nutrient release and retention in container crops. 2016 Proc. Southern Nursery Assoc. Research Conf. 61:174–180
Basiri JahromiN.WalkerF.FulcherA.AltlandJ.2017Photosynthesis, growth, and water use of Hydrangea paniculata ‘Silver Dollar’ produced with different irrigation schedules and biochar substrate amendmentHortScience52S273S274
Basiri Jahromi,N.Walker,F.Fulcher,A.Altland,J.2017Photosynthesis, growth, and water use of Hydrangea paniculata ‘Silver Dollar’ produced with different irrigation schedules and biochar substrate amendment52S273S274)| false
Basiri JahromiN.WalkerF.FulcherA.AltlandJ.WrightW.C.2018Growth response, mineral nutrition, and water utilization of container-grown woody ornamentals grown in biochar-amended pine barkHortScience53347353
Basiri Jahromi,N.Walker,F.Fulcher,A.Altland,J.Wright,W.C.2018Growth response, mineral nutrition, and water utilization of container-grown woody ornamentals grown in biochar-amended pine bark53347353)| false
BeesonR.C.ArnoldM.A.BilderbackT.E.BoluskyB.ChandlerS.GramlingH.M.Lea-CoxJ.D.HarrisJ.R.KlingerP.J.MathersH.M.RuterJ.M.YeagerT.H.2004Strategic vision of container nursery irrigation in the next ten yearsJ. Environ. Hort.22113115
Beeson,R.C.Arnold,M.A.Bilderback,T.E.Bolusky,B.Chandler,S.Gramling,H.M.Lea-Cox,J.D.Harris,J.R.Klinger,P.J.Mathers,H.M.Ruter,J.M.Yeager,T.H.2004Strategic vision of container nursery irrigation in the next ten years22113115)| false
BilderbackT.BoyerC.ChappellM.FainG.FareD.GilliamC.JacksonB.E.Lea-CoxJ.LeBudeA.V.NiemieraA.OwenJ.RuterJ.TiltK.WarrenS.WhiteS.WhitewellT.WrightR.YeagerT.2013Best management practices: Guide for producing nursery crops. 3rd ed. Southern Nursery Association Acworth GA
CaronJ.ElrickD.E.BeesonR.BoudreauJ.2005Defining critical capillary rise properties for growing media in nurseriesSoil Sci. Soc. Amer. J.69794806
Caron,J.Elrick,D.E.Beeson,R.Boudreau,J.2005Defining critical capillary rise properties for growing media in nurseries69794806)| false
FieldsJ.S.OwenJ.S.AltlandJ.E.van IerselM.W.JacksonB.E.2018Soilless substrate hydrology can be engineered to influence plant water status for an ornamental containerized crop grown within optimal water potentialsJ. Amer. Soc. Hort. Sci.143268281
Fields,J.S.Owen,J.S.Altland,J.E.van Iersel,M.W.Jackson,B.E.2018Soilless substrate hydrology can be engineered to influence plant water status for an ornamental containerized crop grown within optimal water potentials143268281)| false
FieldsJ.S.OwenJ.S.ScogginsH.L.2017The influence of substrate hydraulic conductivity on plant water status of an ornamental container crop grown in suboptimal substrate water potentialsHortScience5214191428
Fields,J.S.Owen,J.S.Scoggins,H.L.2017The influence of substrate hydraulic conductivity on plant water status of an ornamental container crop grown in suboptimal substrate water potentials5214191428)| false
GraberE.R.HarelY.M.KoltonM.CytrynE.SilberA.DavidD.R.TsechanskyL.BorenshteinM.EladY.2010Biochar impact on development and productivity of pepper and tomato grown in fertigated soilless mediaPlant Soil337481496
Graber,E.R.Harel,Y.M.Kolton,M.Cytryn,E.Silber,A.David,D.R.Tsechansky,L.Borenshtein,M.Elad,Y.2010Biochar impact on development and productivity of pepper and tomato grown in fertigated soilless media337481496)| false
IncrocciL.MarzialettiP.IncrocciG.Di VitaA.BalendonckJ.BibbianiC.SpagnolS.PardossiA.2014Substrate water status and evapotranspiration irrigation scheduling in heterogenous container nursery cropsAgr. Water Mgt.1313040
Incrocci,L.Marzialetti,P.Incrocci,G.Di Vita,A.Balendonck,J.Bibbiani,C.Spagnol,S.Pardossi,A.2014Substrate water status and evapotranspiration irrigation scheduling in heterogenous container nursery crops1313040)| false
MontesanoF.F.van IerselM.W.BoariF.CantoreV.. D’AmatoGParenteA.2018Sensor-based irrigation management of soilless basil using a new smart irrigation system: Effects of set-point on plant physiological responses and crop performanceAgr. Water Mgt.2032029
Montesano,F.F.van Iersel,M.W.Boari,F.Cantore,V.. D’Amato,GParente,A.2018Sensor-based irrigation management of soilless basil using a new smart irrigation system: Effects of set-point on plant physiological responses and crop performance2032029)| false
ZhangA.F.LiuY.M.PanG.X.HussainQ.LiL.Q.ZhengJ.W.ZhangX.H.2011Effect of biochar amendment on maize yield and greenhouse gas emissions from a soil organic carbon poor calcareous loamy soil from central China plainPlant Soil351263275
Zhang,A.F.Liu,Y.M.Pan,G.X.Hussain,Q.Li,L.Q.Zheng,J.W.Zhang,X.H.2011Effect of biochar amendment on maize yield and greenhouse gas emissions from a soil organic carbon poor calcareous loamy soil from central China plain351263275)| false