Stability of Ecological and Biological Properties of Soils to Chemical Pollution.
Anna A. Popovich, Alena V. Evreinova, Diana K. Aznaurjan, and Sergei I. Kolesnikov. Rostov State Univ, B. Sadovaya str., 105, Rostov-on-Don, 344006, Russia
A series of modeling experiences has been carried out. As objects of research have been used: chernozems, kaschtanozemz, brown wood soil, sandy soils, rendzina. These soils occupy the basic territory of the South of Russia. They essentially differ among themselves on the properties determining stability of soils to chemical pollution, such as the contents of humus, gН, the contents of carbonates, granulometric structure, absorbing ability, biological activity, etc. The soils for modeling experiments were selected from arable horizons. Studies of soil pollution by chemical substances concerning different groups of polluting substances were considerably distinguished on properties. As the representative of heavy metals used copper, nonmetals pollutants - fluorine, organic pollutants - oil. All these substances are priority pollutants in the South of Russia. Studied action of different concentration of polluting substances: copper and fluorine - 1, 10, 100 maximum concentration limits, oil - 1, 5, 10 % from weight of soil. Maximum concentration limit in soil Cu and F is 100 and 500 mg/kg of soil. Copper existed in ground in the form oxid and fluorinewas found in the form of fluoride of calcium. Natural and anthropogenous pollution of soils by fluorine occurs, as a rule, in the form of fluorides, and heavy metals - in the form oxides. Laboratory-analytical measurements were carried out 30 days after pollution. Laboratory-analytical tests have been executed with use standard methods of soil science and biology. The quantity of bacteria, micromycetes, Azotobacter, catalase, invertase, urease and activity, speed of carbamid decomposition, fitotoxicity, the contents of organic matter гумуса, gН and others were determined. As a result of research the following is established. Copper rendered more negative influence than fluorine. On a degree of sensitivity (a degree of reduction in values) the investigated biological parameters settle down as follows: number of Azotobacter > number of micromycetes > number of bacteria > catalase activity > invertase activity. On a degree инфоgмативности (narrowness of correlation with concentration of polluting substance in soil) biological parameters settle down as follows: cellulytic activity > catalase activity > invertase activity > number of bacteria > number of Azotobacter > number of micromycetes. Thus, microbiological parameters appeared more sensitive, and biochemical parameters were more informative. It testifies to expediency of their sharing. Chernozems, kaschtanozemz, rendzains are steadier to pollution, and brown wood soils and sandy soils - more sensitive.