EFFECT OF AGROCHEMICAL USE ON WATER QUALITY OF A STREAMFLOWING THROUGH THE FARM SETTLEMENT AT EWEJE, ODEDALOCAL GOVERNMENT AREA OGUN STATE NIGERIA

Abstract

The study examined the impact of agrochemicals (chemical fertilizers, herbicides and pesticides) used in crop production on the quality of surface water of a stream flowing through a farm settlement. Water samples were collected at four points along the stream, before the farm (BF), within the farm 1 (WF1), within the farm 2 (WF2) and after the farm (AF) on monthly basis in a 3-month period. Collected samples were analyzed using standard methods for parameters such as pH, Electrical conductivity (EC), COD, DO, Turbidity, Total Hardness, Nitrates and Phosphates and also for some agrochemicals active ingredients such as Glyphosphate, Atrazine, Cypermethrin, Mancozeb, Paraquat and Cyfluthrin. The results for the parameters listed above ranged from 5.72 - 6.75, 23.50 - 37.50 µScm-1, 1.38 - 13.72 mg/L, 3.63 - 23.48 mg/L, 18.45 – 10 mg/L, 5.63 - 37.5 NTU, 72.11 - 106.50 mg/L, 5.5 - 18.43 mg/L, 7.5 - 16.64 mg/L, 0.19 - 0.37 mg/L, 0.04 - 0.13 mg/L, 0.11 - 0.21 mg/L, 0.03 - 0.08 mg/L, 0.04 - 0.11mg/L, 0.19 - 0.3mg/L respectively. The results of the ANOVA and Principal Component Analysis (PCA) was significant (p <0.05) for pH, EC, Total hardness, Phosphate, Glyphosphate, Atrazine and Cyfluthrin between the locations and between months for all parameters except for Phosphate. Agricultural activities in the area polluted the surface water flowing through it.