Effect of Various Herbicides on the Respiration of Soil Microorganisms

Abstract

The effect of Ametryne, Atrazine, Bromacil, Diuron, Fluometuron, Linuron, Prometryne, Terbacil, Trifluralin, and 2,4-D on soil respiration was studied employing the Warburg apparatus. These compounds were used in various concentrations, i.e., 0, 10, 100, and 250 p.p.m. The 10 compounds fell into three categories with regard to their effect on respiration of soil microorganisms: 1. A significant inhibitory effect on oxygen uptake was brought about by adding 2,4-D and Trifluralin to Coto and Fraternidad soils. 2. A weak inhibitory effect on oxygen uptake was noted for low concentrations of Bromacil, Diuron, Trifluralin, and 2,4-D, and for high concentrations of Ametryne, Bromacil, Linuron, and Diuron in soils. 3. A weak to moderate stimulatory effect on oxygen uptake was recorded with low concentrations of Ametryne, Diuron, Fluometuron, 2,4-D and for high concentrations of Atrazine, Linuron, and Terbacil in soils.