Umus Degradation under the Influence of Simulated "Acid Rains"

1990

S. 419-443

6 Abb., 4 Tab., 4 Lit. Ang.

Unselbständiges Werk

200085940

The purpose of these investigations was to define the changes going on in soil under the influence of simulated "acid rains". It wachachieved by treating three kinds of soil with water solutions with pH: 2.0, 3.0, 4.0, 5.0, 6.0, 7.8 for two vegetation periods. As the result, in the examined soils differences were found in the pH of soils amounting to 2.5 of the unit, in the sorption complex the content of H+ ions increased and the sum of bases decreased considerably. Significant changes in the number of bacteria, fungi, macromycetes were found - in the most acid solutions they decreased by 100%. The processes of nitrification, cellulose decomposition and soil respiration were reduced, whereas ammonification was stimulated. Under the influence of "acid rains" the content of crbon and nitrogen remained unchanges, while the content of both fulvic and grey and brown humic acids was reduced. Together with the increase in soil acidity grew the content of hymatomelanic acids. No significant changes in the content of bitumen, humins, humic carbon and the (Formel) index of colour were noted under the influence of simulated "acid rains".