Influence of salts on the microbial activities in arid and semi-humid soils.

Abstract

The influence of salt mixtures consisting of Ca(H2PO4)2, trace elements, CaSO4, CaCO3, Na2CO3, NaCl and K2SO4 in different combinations on the nitrifying power, evolution of carbon dioxide and the total number of bacteria was studied in arid soils (sandy and alluvial) and semi-humid ones (chernozem and rendzina). Salt mixtures comprising of either mono-calcium phosphate or sodium chloride showed highly inhibiting action on the studied microbial activities in sandy, alluvial and chernozem soils, whilst mono-calcium phosphate stimulated the heterotrophs of rendzina. Trace elements stimulated the autotrophs of the clay soils. The other different salts mixtures acted according to the salt combination and nature of the microbial activity.