Enzymatic activities in salt affected soils

Activities of dehydrogenase, urease, and phosphatase (nuclease) as affected by the anionic and cationic form of inorganic salts (SO₄, CO₃, and CI for Ca, Mg, K, and Na) applied at 15 meq/100 g soil to alluvial clay and calcareous sandy loam soils, during incubation, were studied. Most of the applied salts stimulated the enzyme activities of soils tested. Carbonates showed the most distinct effect, while chlorides were the least. Nuclease in both soils was activated by all of the applied salts. Dehydrogenase in the calcareous soil was stimulated by all types of salts used. Urease, in the alluvial soil, was promoted by all sulphates and chlorides applied. Urease, in the calcareous soil, was inhibited by chloride salts. In the alluvial soil, sodium as combined with each of the three aniones favoured the enzyme activities; potassium and magnesium showed intermediate figures, while calcium was extremest. In the calcareous soil, potassium in its different forms favoured the enzyme activities; sodium and magnesium showed intermediate results, and calcium gave the least values.

In alluvialem Ton sowie kalkhaltigem sandigen Lehm wurde die Wirkung von Ca, Mg, K und Na in Sulfat-, Karbonat- und Chloridform (15 mval/100 g Boden) auf die Aktivität von Dehydrogenase, Urease und Phosphatase (Nuklease) geprüft. Die meisten Salze stimulierten die Enzymaktivitäten, die Karbonate am deutlichsten, die Chloride am wenigsten. Nuklease wurde bei beiden Böden durch alle Salze aktiviert. Urease wurde im alluvialen Boden durch die Sulfate und Chloride gefördert, im kalkhaltigen sandigen Lehm durch die Chloride inhibiert. Im alluvialen Boden begünstigte Na in jeder Salzform die Enzymaktivitäten, Kalium und Magnesium nahmen eine Mittelstellung ein, Kalzium bewirkte die geringsten Stimulierungen. Im kalkhaltigen Boden förderte Kalium in Verbindung mit allen Anionen die Enzymaktivitäten Kalzium hingegen kaum.