Assessment of Agoro irrigation scheme water quality and its effect on soil quality

Abstract

ix ABSTRACT “Whenever we irrigate our crops with the scheme water, even the previously well-established crops starts wilting,” Farmers at Agoro irrigation scheme claimed. The main objective was to investigate the quality of water and soil at the scheme. Laboratory method of analysis was used and data were obtained based on experiments. For the first and second sets of the experiment, the average values for the parameters for samples at source were; Electrical Conductivity- 0.855dS/m, Nitrates- 4.22mg/l, Chlorides- 2.945mg/l, Boron- 0.52mg/l, Sodium- 0.31me/l and SAR- 0.546. For samples at reservoir; Electrical Conductivity- 2.43dS/m, Nitrates- 4.14mg/l, Chlorides- 1.64mg/l, Boron- 0.63mg/l, Sodium- 0.314me/l and SAR- 0.529. For samples taken from three points along the canal, the results were; Electrical Conductivity-2.285dS/m, Nitrates-3.85mg/l, Chlorides-2.21mg/l, Boron-0.58mg/l, Sodium-0.313me/l and SAR-0.511. The soil samples taken from 19 plots were investigated for pH and electrical conductivity before and after applying water into it and averaged. The pH values for plots were grouped in ranges of acceptance as; 6-8.5 for plots M, L, T, R, N, A, J, P, O, G, H, Q, B, C and F. pH in the range of non-acceptance as >8.6 for plots D, K and S. The Electrical Conductivity values were grouped in a range of 0.8-3 dS/m which restricts growth of some crops and all plots were within that range. Salinity problem maybe originating from the reservoir as the EC values showed. The water from canal which comes from the reservoir has an effect on the soil since both the pH and the EC values increased when water was applied.