A Comparative Evaluation of Three Tests for Determining Plant-Available Manganese in Soils
1982
Sharpe, R. R. | Parks, W. L.
Amounts of manganese extracts from soil by three well-known methods were compared to each other and to soil levels of Ca, P, Fe, and K and soil pH. Seventy-one soil samples, representing seven soil series, which are members of either the Ultisol or Alfisol orders, were used in the comparisons of soil extraction procedures. The average amount of soil Mn extracted by each procedure was determined for each soil series. The correlations among extractants were very high and the Mehlich-1 procedure extracted three to four times more Mn than the DTPA procedure and five to six times more than the NH₄0Ac procedure. As the pH of a soil decreased, the amount of extractable Mn increased. The relationship between the Mehlich-1 procedure and pH was less than between the other extractants and pH. Plant samples were collected in conjunction with the soil samples and soil Mn as determined by each method was correlated with plant concentrations. Correlations between plant Mn and soil Mn indicates that the Mehlich-1 extractant may not be as reliable as the NH₄0Ac or DTPA extractants because the correlations between Mehlich-1 extractable Mn and Mn in cotton and corn plants were poor.
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