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Globally, irrigated agriculture is the largest extractor and the most frequent consumer of groundwater resources, with important groundwater-dependent and largely spread agro-economies. Quality of irrigation water is one of the key factors which have either direct or indirect impact on plant growth, soil and water management practices and plant yields. This work aims at highlighting the importance of periodic assessment of groundwater quality for irrigation, impact of different chemical parameters on plant yield and agriculture and water management practices needed in adverse irrigation water conditions. This study was conducted in semi-arid area where salinity and alkalinity are considered the main threats to the sustainable irrigation agriculture. Thirty representative samples were collected for chemical analyses from various sources of groundwater, within an area of 36 km(2), lying in the north-east of the Lakki Marwat district Pakistan. The standard values suggested by WAPDA, FAO and USDA Handbook 60 were used as benchmark for comparison. The electrical conductivity and pH values together classify groundwater as saline-alkaline. It is revealed that none of the water samples has an adverse impact on the yield of barley, sorghum and wheat while 7% and 17% of this water respectively reduce the yield of corn and onion by 50%. Besides, 7% of this water reduces the yield of alfalfa by 25%. This work recommends management practices such as deep ploughing, provision of adequate drainage and crop rotation for improving the use of such water.