Atrazine-induced alteration in soil microbial activities and plant nutrient uptake efficiency in the soil

Abstract

The use of herbicides such as atrazine has gained wide acceptance by farmers
because of their ability to control numerous weeds, which has led farmers to
apply it without considering their recommended dose. This work aimed to
assess its effects on nutrient status, nutrient uptake by maize plants and
microbial activities as indicators of soil health. The soil nutrient status, nutrient
uptake by plants, soil enzyme activities and microbial population in the soil
were determined via the standard method. The results of the analysis revealed
no significant difference in the nutrient status of the soil or nutrient uptake by
the plants compared with those of the control. The average P content of the soil
was greater (7.12 ppm) in the soil treated with the recommended dose and
lowest (1.45 ppm) in the plot sprayed with two times the recommended dose.
The results of the enzyme activity assays revealed an increase in amylase
activity in the soil treated with twice the recommended dose, with an amylase
activity of 28.2 μg glucose/g soil, compared with that of the other treatments.
The lowest concentration was observed in the soil without any herbicide
treatment (12.8 μg glucose/g soil). A similar trend was observed in the
phosphatase activity of the soil, with the highest phosphatase activity of 13.20
μg p-nitrophenylphenol/g soil recorded in the soil after the recommended dose
was doubled. The results of these studies revealed that atrazine had a relatively
small effect on the soil and plants when the recommended dose was applied.