title: An evaluation of MES (2(N-Morpholino)ethanesulfonic acid) and Amberlite IRC-50 as pH buffers for nutrient solution studies.
abstract: All buffering agents used to stabilize pH in hydroponic research have disadvantages.  Inorganic buffers are absorbed and may become phytotoxic.  Solid carbonate salts temporarily mitigate decreasing pH but provide almost no protection against increasing pH, and they alter nutrient absorption.  Exchange resins are more effective, but we find that they remove magnesium and manganese from solution.  We have tested 2(N-Morpholino)ethanesulfonic acid (MES) as a buffering agent at concentrations of 1 and 10  mol m-3 (1 and 10 mM) with beans, corn, lettuce, tomatoes, and wheat.  MES appears to be biologically inert and does not interact significantly with other solution ions.  Relative growth rates among controls and MES treatments were nearly identical for each species during the trial period.  The pH was stabilized by 1 mol m-3 MES.  This buffer warrants further consideration in nutrient research.
authors.affiliation: Plant Science Department, Utah State University, Logan 84322, USA.
authors.forename: B G
authors.initials: BG
authors.lastname: Bugbee
authors.forename: F B
authors.initials: FB
authors.lastname: Salisbury
mesh_terms: D017738:Alkanesulfonic Acids / Q000737:chemistry / Q000494:pharmacology*; D000837:Anion Exchange Resins / Q000737:chemistry / Q000494:pharmacology*; D002021:Buffers; D002614:Chelating Agents / Q000494:pharmacology; D018556:Crops, Agricultural / Q000187:drug effects* / Q000254:growth & development; D003470:Culture Media / Q000032:analysis; D004492:Edetic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D005069:Evaluation Studies as Topic; D007887:Fabaceae; D006863:Hydrogen-Ion Concentration; D018527:Hydroponics / Q000379:methods*; D007501:Iron / Q000378:metabolism; D018545:Lactuca; D018551:Solanum lycopersicum; D009025:Morpholines / Q000737:chemistry / Q000494:pharmacology*; D009751:Nutritional Requirements; D010946:Plants, Medicinal; D012117:Resins, Synthetic; D014908:Triticum; D003313:Zea mays
chemical_list: D017738:Alkanesulfonic Acids; D000837:Anion Exchange Resins; D002021:Buffers; D002614:Chelating Agents; D003470:Culture Media; D009025:Morpholines; D012117:Resins, Synthetic; C004550:2-(N-morpholino)ethanesulfonic acid; C024946:Amberlite IRC50; D004492:Edetic Acid; D007501:Iron; C026060:N-(hydroxyethyl)ethylenediaminetriacetic acid