The soil reaction value depend on the soil percentage base saturation degree and of the saturation type (predominantly with calcium or sodium). At the same time, the soil moisture regime, percolative or periodically percolative, the long application of nitrogen fertilizers, acid pollution, determine the deep leaching of bases. So, the upper part of soil suffers an acidification process especially under the conditions without liming. Generally, soil pH values less than 5,5 ensure conditions for strong solubilization of pollutants and their translocation into plants. Particular problems are raised by the very strongly and strongly acid soils (0,60% and 6,57%, respectively), some of the being specific for the mountainous pastures. In Romania are 1 867 000 ha acid agricultural land, representing over 12% from the total agricultural surface of the country. On the other hand, in Romania are produced annually from 0.18 to 0.2 million tones ladle slag (LF slag) from steel refinery, classified as a dangerous waste due to its alkalinity (alkalinity index 3.5-4.5)
