Extraction Methods for Estimating Available Manganese to Maize (Zea mays L.) in Acid Soils
Ernest U. Eteng *
Department of Soil Science and Meteorology, Michael Okpara University of Agriculture, Umudike, Nigeria
Damian O. Asawalam
Department of Soil Science and Meteorology, Michael Okpara University of Agriculture, Umudike, Nigeria
*Author to whom correspondence should be addressed.
Abstract
Twenty surface soil samples were used to evaluate status of soil Mn using five extraction procedures (Coca-cola, EDTA, HCl, EDTA + NH4OAC and NH4OAC methods). The results show that Coca-cola method extracted the highest amount of the Mn while NH4OAC extracted the least amount of Mn. The results also showed that among the five extractants examined, the highest regression coefficients were found between Coca-Cola and HCl, HCl and EDTA+NH4OAc and, EDTA and EDTA+NH4OAc-extractable Mn for Mn uptake, respectively. Accordingly, the study indicates that, the comparative extraction capacity of these extractants followed the order: Coca-cola> HCl> EDTA> EDTA+NH4OAc> NH4OAC.
Keywords: Acid soil, critical limits, extractants, grain yield, maize, Mn sulphate, Mn uptake, optimum levels