Molybdenum Accumulation by Corn and Soybeans from a Molybdenum-rich Sewage Sludge
1986
Pierzynski, Gary M. | Jacobs, L. W.
An anaerobically digested sewage sludge containing 1500 mg Mo/kg was applied to add 0 to 300 kg Mo/ha in two separate experiments. This field study was conducted with corn (Zea mays L.) and soybeans [Glycine max (L.) Merr.] over a 3-yr-period to evaluate high Mo additions to soils from the application of Mo-contaminated wastes. A total Mo analysis of soils sampled after the third growing season accounted for 97% of the applied Mo in two sludge treatments. Concentrations of Mo in whole plant, diagnostic tissue, and grain samples from both crops were significantly increased with any sludge treatment. Lime residues in the sludge increased soil pH's from 4.8 to 7.1 resulting in further Mo accumulation in the plant samplings. Four soil extractants [1.0 M NH₄HCO₃ + 0.005 M DTPA, 1.2 M NaC₂H₃O₁,Tamm's acid ammonium oxalate, and 0.5 M (NH₄)₂HPO₄] in combination with soil pH were evaluated for their ability to predict Mo concentrations in the plant samplings. Soil pH became significant in the prediction equations when considering more than 1 yr of data. None of the extractants were proven to be clearly better or worse than the others. Further testing of the ammonium bicarbonate-DTPA extractant is recommended because of its potential for simultaneous use with other plant nutrients and heavy metals in the soil during multielement analysis, as well as the ease by which it can be analyzed using plasma emission.
显示更多 [+] 显示较少 [-]