title: Timing for a sustainable fertilisation of Glycine max by using HBED/Fe3+and EDDHA/Fe3+chelates.
abstract: BACKGROUND
  Efficient use of Fe chelates is crucial to avoid environmental risks and reduce economic losses. HBED/Fe3+has been recently approved by the European Union for soil fertilisation, but studies delving into the best timing for its application are necessary. In this work, a batch incubation experiment and two biological experiments were developed to determine the optimal physiological stage for a sustainable application of HBED/Fe3+in soil fertilisation compared with EDDHA/Fe3+fertilisers using57Fe.
  
  
  RESULTS
  HBED/Fe3+demonstrated a high durability in soils and soil materials, maintaining more than 80% of Fe chelated after 70 days, and its application at an early physiological stage resulted in a high Fe accumulation in soybean and soil after 36 days. In contrast, the stability of EDDHA/Fe3+decreased because of the retention of its lowest stable isomers. The best timing for chelates application was confirmed in a 52 day experiment. The application of HBED/Fe3+at the early stage increased the Fe translocation to fruits; while o,o-EDDHA/Fe3+accumulated more Fe in fruits when added at the fructification stage.
  
  
  CONCLUSIONS
  The high HBED/Fe3+stability in calcareous soil requires a differentiate application timing, and its addition at early physiological stages leads into the most efficient fertilisation. © 2016 Society of Chemical Industry.
authors.affiliation: Department of Agricultural Chemistry and Food Science, Faculty of Science, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
authors.forename: Clara
authors.initials: C
authors.lastname: Martín-Fernández
authors.affiliation: Department of Agricultural Chemistry and Food Science, Faculty of Science, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
authors.forename: Sandra
authors.initials: S
authors.lastname: López-Rayo
authors.affiliation: Department of Agricultural Chemistry and Food Science, Faculty of Science, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Hernández-Apaolaza
authors.affiliation: Department of Agricultural Chemistry and Food Science, Faculty of Science, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Lucena
mesh_terms: D000327:Adsorption; D003692:Delayed-Action Preparations / Q000737:chemistry*; D004492:Edetic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D005029:Ethylenediamines / Q000737:chemistry; D005308:Fertilizers / Q000032:analysis*; D007501:Iron / Q000737:chemistry* / Q000378:metabolism; D007502:Iron Chelating Agents / Q000737:chemistry*; D007536:Isomerism; D012987:Soil / Q000737:chemistry; D013025:Glycine max / Q000254:growth & development* / Q000378:metabolism
chemical_list: D003692:Delayed-Action Preparations; D005029:Ethylenediamines; D005308:Fertilizers; D007502:Iron Chelating Agents; D012987:Soil; C011813:ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid); C037740:N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid; D004492:Edetic Acid; D007501:Iron
keywords: 57Fe; EDDHA isomers; calcareous soil; chelate retention; iron fertilisers; soybean