CHANGES IN SOIL MICROBIAL-FLORA AFTER SODIUM-CHLORIDE APPLICATION WITH OR WITHOUT AMMONIUM-SULFATE ADDITION

The effect of the addition of NaCl at various concentrations or of a mixture of NaCl and (NH4)2SO4 to non-saline sandy loam soil in Thailand, and the changes in both number and kinds of soil microorganisms were examined periodically. The number of fungi increased with the increase of the NaCl concentration when NaCl was solely added to the soil and Penicillium sp. were dominant in the fungal flora. In contrast, the numbers of bacteria and actinomycetes decreased by the addition of NaCl. The combined addition of NaCl and (NH4)2SO4 decreased the number of fungi, although fungal population became more complex. In contrast, (NH4)2SO4 application to the NaCl-treated soils did not show an additional effect on the number of bacteria.