Effects of irrigation water quality on soil Microbial Enzyme activities and Crop quality in Minna, Niger State

Abstract

The quality of irrigation water is of paramount importance in the knowledge of the end products of cultivation, as well as the subsequent health of the soil. To this effect, soil samples were collected from five locations under urban and peri-urban agriculture in Minna metropolis and its environments, which are principally irrigated from canals running through the city. Across the locations, soil samples collected at a depth of 0 - 15cm, were analyzed for physical and chemical properties. Soil pH, Electrical Conductivity, Total Nitrogen, Available Phosphorus, and Organic Carbon contents were 8.23, 193µ2/cm, 0.16mg/kg, 4.32 mg/kg, and 1.14 %, averagely, across sites. So also, water samples were collected at a depth of 0-15cm, yielding ranges of pH, Electrical Conductivity, Organic Carbon, Lead and Zinc, of 6.56-7.98, 0.14 - 1.04ds/m, 0.53-0.72 mg/l, 0.00-0.02 mg/l, and 0.04-0.44 mg/l, respectively. The results of analysis and evaluation of water samples across treatment locations revealed that the water is suitable for irrigation based on results of EC, SAR, Specific ion toxicities, and Heavy metal analysis. Their suitability/quality for irrigation purposes occurred in the following order: Kanfanin Kutare>Gidan Mangoro>Morris> Opposite Federal Secretariat> Ketaren Gwari. Water sampled from Ketaren Gwari is noted to be the zone of increasing problems. The results of the analysis of plants in these locations showed that vegetables in Gidan Mangoro, Kafanin Kutare, Opp. Fed. Secretariat showed no traces of lead contamination. there was no trace of copper across three sites namely: Kafanin Kutare, Opp. Fed. Secretariat, and Morris. Cadmium content of the plants in Gidan Mangoro, Morris and Ketaren Gwari exceeded the permissible limits set by FAO (2015). Further analysis of enzymatic activities showed that dehydrogenase, Urease and Alkaline phosphatase activities were positively correlated with most of the water quality parameters which indicates that an increase in the concentration of the chemical properties of irrigation water will lead to a significant increase in the activities of Dehydrogenase, Urease and Alkaline Phosphatase.