title: Novel chelating agents for iron, manganese, zinc, and copper mixed fertilisation in high pH soil-less cultures.
abstract: BACKGROUND
  Studies about simultaneous fertilisation with several micronutrients have increased in recent years, as Fe, Mn and Zn deficiencies may appear in the same culture conditions. In fertigation, the replacement of sulfates by synthetic chelates is essential in areas with high pH irrigation water and substrates. Ethylenediamine-N-(2-hydroxyphenylacetic acid)-N'-(4-hydroxyphenylacetic acid) (o,p-EDDHA) and ethylenediamine disuccinic acid (EDDS) are novel chelating agents whose efficacy in simultaneous fertilisation of Zn, Mn and Cu is unknown. This work evaluates the effectiveness of both ligands compared to traditional ligands (EDTA, HEEDTA and DTPA) applied as micronutrient chelate mixtures to soybean and navy bean plants grown in soil-less cultures at high pH by analysing the SPAD and micronutrient nutritional status, including the Composition Nutritional Diagnosis (CND) analysis tool.
  
  
  RESULTS
  The application of micronutrients using o,p-EDDHA was more effective in providing Mn and Zn than traditional ligands or sulfates. The application using EDDS increased the Zn nutrition. The results are well correlated with the chemical stability of the formulations.
  
  
  CONCLUSIONS
  The combined application of Mn and Zn as o,p-EDDHA chelates can represent a more effective source than traditional chelates in micronutrient fertiliser mixtures in soil-less cultures at a high pH.
authors: Departamento de Química Agrícola, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
authors: Sandra
authors: http://orcid.org/0000-0002-5035-0311
authors: S
authors: López-Rayo
authors: Departamento de Química Agrícola, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
authors: Paloma
authors: P
authors: Nadal
authors: Departamento de Química Agrícola, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
authors: Juan J
authors: JJ
authors: Lucena
mesh_terms: D017756:Aquaculture; D002614:Chelating Agents / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D005308:Fertilizers / Q000032:analysis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D008345:Manganese / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry
chemical_list: D002614:Chelating Agents; D005308:Fertilizers; D019216:Metals, Heavy; D008345:Manganese; D003300:Copper; D007501:Iron; D015032:Zinc
keywords: CND; micronutrients; navy bean; soil-less; soybean