The Complex Effect of Soil Temperature and Soil Moisture as Factors Regulating the Soil Flora

D. FEHER THE investigations of the last years have shown that the quantitative occurrence of soil microorganisms is subject to continuous variation and temporar y fluctuation. Because of this pulsating lif e of the soil, directly and indirectly, its biochemical composition is continuousl y changed. The soil consequentl y becomes a dynamicall y active living mass. Our most recent investigations have had the object of establishing the fundamenta l causes of the variations which we have followed in their characteristic s for ten years. These investigations have led to the following conclusions : Temperatur e and moisture of the soil are regulative biofactors which work in a complex way and influence it mutually. By mathematica l treatment involving three dimensional analysis, we were able to bring proof that the product , temperature , X moisture = R, a regulative factor complex representin g the climatic factors through dependenc e upon which is caused the periodicity of the soil life. The establishmen t of this R value and its associate d physiological action is unequivocall y described in the gas analysi s coordinat e system. So long as the two component s stay within their optimum limits, they are favorabl e physiologi cally. If one or both component s pass their optimum limits, they act unfavorably. We were able to extend the validity of the law also to the temperatur e and water content of the higher plants. The possibility occurs that through a suitabl e extension of the mathematica l treatment similar investigation of other variable factors may be success full y undertaken. — Author abstract translated by Alvin W. Hofer.