ABSTRACT
This study was carried out to determine the effect of Atrazine on Bacteria and Fungi population of soil under Plantain plantation. The soil samples used were collected from a Plantain Plantation in located in the Crop science departmental research Farm, Capitol, University of Benin, Benin City, Edo State. The treatments were, the control (0 ml), recommended field rate (0.004485g) and twice the recommended field rate (0.00897g) of the herbicide, each applied to 3kg of soil. Bacteria and Fungi population were then determined at seven days interval up to the 14th day after treatment (i.e., day 0, 7 and 14) and the Physical and chemical properties of the soil samples were determined at the beginning, middle and end of the experiment (i.e. day 0, 7 and 14).
The results confirmed that Atrazine was able to increased the Chemical properties of the soil. At Day 0, it increased the pH, total Nitrogen, total Organic Carbon and Average Phosphorus from 6.05, 0.95gkg–1, 19.00gkg–1, 25.03 mgkg–1 (control) to 6.37, 1.04 gkg–1, 20.83 gkg–1, and 37.87 gkg–1 (RR) respectively as well as the Calcium, Magnesium, Sodium, Potassium, and Aluminium contents of the soil but the effect was slightly reduced in samples treated with double the recommended rate. The textural class remained Loamy sand. At Day 0, the Bacteria population increased from 7.10 cfug–1 to 11.70 cfug–1 when Atrazine was applied at recommended rate but slightly reduced to 7.73 cfug–1 at double the recommended rate, at Day 7, it increased from 7.90 cfug–1 (control) to 14.77 cfug–1 (RR) and then to 15.38 cfug–1 (2RR), at Day 14 it increased from 8.28 cfug–1 (control) to 16.97cfug–1 (RR) and then to 17.93 cfug–1 (2RR). For the Fungi population, at Day 0, it increased from 4.92 cfug–1 (control) to 14.67 cfug–1 (RR) and then to 15.55 cfug–1. At Day 7, it increased from 9.90cfug–1 (control) to 20.7 cfug–1 (RR) and then to 22.97 cfug–1 (2RR), at Day 14, the population increased from 8.28 (control) to 16.97 cfug–1 (RR) and then to 17.93 cfug–1 (2RR). The results further confirmed that Atrazine significantly affects soil properties.
