Effect of zinc source applied to soils on its availability to navy bean

The objective of this study was to compare the mobility, availability, and relative effectiveness of Zn from liquid Zn-diethylenetriamine-pentaacetate-N-2-hydroxyethyl-ethylenediamine-triacetate-ethylenediamine-tetraacetate (Zn-DTPA-HEDTA-EDTA or Zn-D-H-E) and Zn-aminelignosulfonate (Zn-AML) sources applied to weakly acidic (moderate permeability) and calcareous (moderate to rapid permeability) soils at different Zn levels in a navy bean (Phaseolus vulgaris L.) greenhouse experiment during a 60-d period. Zinc behavior in soil was evaluated by single and sequential extractions. The addition of the two Zn complexes produced a considerable increase in Zn concentration in the water-soluble plus exchangeable and organically complexed fractions. The Zn-D-H-E source resulted in greatly increased mobility of Zn through the soils in comparison with the control (no Zn addition) and the Zn-AML source at the highest dosage (10 mg Zn kg(-1)); 11 and 32% of total applied Zn was lost in weakly acidic and calcareous soils, respectively, through leaching. Zinc application increased the plant dry matter yield compared with the control treatment in the weakly acidic soil; however, there were no significant differences between the Zn rates of 5 and 10 mg kg(-1). All sources of Zn increased the amount of Zn uptake in plants. The Zn-D-H-E was more effective than Zn-AML in the calcareous soil but had a similar effect in the weakly acidic soil. Soluble Zn extracted from plant dry matter with reactive 2-(N-morpholino)ethanesulfonic acid (MES) could be used to diagnose the nutritional status of Zn in navy bean.