Efficiency of a new strategy involving a new class of natural hetero-ligand iron(III) chelates (Fe(III)-NHL) to improve fruit tree growth in alkaline/calcareous soils.
BACKGROUND
Iron (Fe) chlorosis is a serious problem affecting the yield and quality of numerous crops and fruit trees cultivated in alkaline/calcareous soils. This paper describes the efficiency of a new class of natural hetero-ligand Fe(III) chelates (Fe-NHL) to provide available Fe for chlorotic lemon trees grown in alkaline/calcareous soils. These chelates involve the participation in the reaction system of a partially humified lignin-based natural polymer and citric acid.


RESULTS
First results showed that Fe-NHL was adsorbed on the soil matrix while maintaining available Fe for plants in alkaline/calcareous solution. The effects of using three different sources as Fe fertilisers were also compared: two Fe-NHL formulations (NHL1, containing 100% of Fe as Fe-NHL, and NHL2, containing 80% of Fe as Fe-NHL and 20% of Fe as Fe-ethylenediamine-N,N'-bis-(o-hydroxyphenylacetic) acid (Fe-EDDHA)) and Fe-EDDHA. Both Fe-NHL formulations increased fruit yield without negative effects on fruit quality in comparison with Fe-EDDHA. In the absence of the Fe-starter fraction (NHL1), trees seemed to optimise Fe assimilation and translocation from Fe-NHL, directing it to those parts of the plant more involved in development.


CONCLUSIONS
The field assays confirmed that Fe-NHL-based fertilisers are able to provide Fe to chlorotic trees, with results comparable to Fe-EDDHA. Besides, this would imply a more sustainable and less expensive remediation than synthetic chelates.
CIPAV TimacAGRO International-Roullier Group, Polígono Arazuri-Orcoyen, Orcoyen, Spain.
Marta
M
Fuentes
María F
MF
Ortuño
Francisco
F
Pérez-Sarmiento
Eva
E
Bacaicoa
Roberto
R
Baigorri
Wenceslao
W
Conejero
Arturo
A
Torrecillas
José M
JM
García-Mina
D000327:Adsorption; D002957:Citrus / Q000254:growth & development* / Q000378:metabolism; D005029:Ethylenediamines / Q000008:administration & dosage; D005290:Ferric Compounds / Q000008:administration & dosage* / Q000378:metabolism; D005308:Fertilizers; D006863:Hydrogen-Ion Concentration; D007501:Iron; D007502:Iron Chelating Agents / Q000008:administration & dosage* / Q000378:metabolism; D012987:Soil / Q000032:analysis*
D005029:Ethylenediamines; D005290:Ferric Compounds; D005308:Fertilizers; D007502:Iron Chelating Agents; D012987:Soil; C011813:ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid); D007501:Iron