Neutralising acid soils for the indespensable microelements mobility

Abstract

As a highly vital issue, plant nutrition on acid soils is known for the fact that increasing content of some elements (Al, Fe, Mn) may also increase in the plants causing a symptomatic toxicity to plants. Likewise, the presence of such elements in the soil adsorptive complex leads to lower saturated colloid soils with alkali cations. Allowing for P binding to barely soluble Al, Fe and Mn phosphates, the shortage of P in the soil could be also expected.

Therefore, liming is recommended to help grow crops on the acid soils. An efficiently performed liming on them is manifested in an altered micro- and macroelements content, further subdued to changes in the plant nutritional system. Some of the amelioration measures exerting changes in the soil acidity were also attempted, with a special emphasis given on reducing mobile Al content and on the available Fe and Mn forms, having been extremely high before the experiment.

A 3-year experiment was conducted on the pseudogley soil of an extremely acid reaction (pH/KCl 3,52-3,58) and of an extremely high mobile Al content (37,9-41,7 mg/100 g soil), with bentonite along with CaO and CaO+MgO used to reduce soil acidity, and maize as a test crop.

Research results demonstrated that the lower soil acidity was, the lower Al and available Mn and Fe forms were, so being directly correlated with increased pH, but not with Zn and Cu values which remained nearly the same. Mn, Fe, Cu and Zn contents in maize leaf and grain seemed to be slight, thereby not manifesting lawfulness to the amelioration measures taken.