Effect of selected herbicides on activities of microorganisms in soils |
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Authors: | C M Tu |
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Institution: | Pest Management Research Centre , Agriculture and Agri‐FoodCanada , 1391 Sandford Street, London, Ontario, N5V 4T3, Canada |
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Abstract: | Abstract With the exception of EPTC, herbicide treatments showed inhibitory effects on bacterial colony counts in a sandy loam soil for the first week. Monolinuron and simazine were stimulatory to the growth of fungi in the organic soil after 2 wk. None of the herbicide treatments affected nitrification during the first week of incubation. Except the treatment of EPTC in organic soil, all herbicides inhibited nitrification after 2 wk in both soils. All herbicide treatments stimulated SO4 formation during the 8‐wk period in the sandy loam soil. Simazine and tridiphane also stimulated sulfur oxidation after 4 wk in an organic soil. With the exception of EPTC and nitrapyrin, no significant inhibitory effect on the amount of biomass‐C was observed in the organic soil. A stimulatory effect on denitrification was observed with EPTC for 2 wk and monolinuron for 1 wk in the sandy loam soil and with simazine and tridiphane after 2 wk in the organic soil. It is apparent that the indigenous soil microorganisms can tolerate the effects of the chemicals for control of soil weeds. |
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Keywords: | Herbicide microorganism nitrification denitrification sulfur oxidation biomass‐C oxygen‐consumption soil |
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