ASSESSMENT OF WATER QUALITY OF RIVER MINJIBIR FOR IRRIGATION PURPOSES IN KANO STATE, NIGERIA

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1 ASSESSMENT OF WATER QUALITY OF RIVER MINJIBIR FOR IRRIGATION PURPOSES IN KANO STATE, NIGERIA ABSTRACT Yahaya 1, M. N., Umar 2, F. G., Jibrin *1, D. M. and Idris 1, U. D. 1 Samaru College of Agriculture, Division of Agricultural Colleges, Ahmadu Bello University Zaria. 2 Department of Soil Science, Faculty of Agriculture, Bayero University Kano. *dahiru62@yahoo.com This study was conducted to assess the suitability of the water from river Minjibir, in Minjibir local government area of Kano state, for irrigation purposes. The physico-chemical study reveals the quality of water and its suitability for Agricultural purposes. Electrical Conductivity (EC), Sodium Percentage (Na %), Sodium Adsorption Ratio (SAR), Residual Sodium Carbonate (RSC) were used as a criteria for finding the suitability of irrigation waters. Major cations; Na +, Ca 2+, Mg 2+, B + and major anions; Cl -, SO 4 2-, HCO 3 -, CO 3 2- and NO - were determined from 18 Samples, Six Sampling points were established over a distance of 0.6 km upstream of the irrigation river. A total of 18 water samples representing three (3) samples from each established point were collected, from March 2013 to April 2013 to assess the hazards of salinity, sodium and bicarbonate. The study reveals that the water used for irrigation in river Minjibir contain salt; therefore, continuous use of the water for irrigation is highly discouraged as this could lead to soil salinity problem, which will in turn affect the productivity and sustainability of the irrigation activities along the river. This is because most crops (maize, tomato, pepper, okra, etc) are sensitive to salinity and only few are tolerant, which means only those few crops could be grown in that area. INTRODUCTION The world s cultivated area has grown by 12% over the last 50 years. Over the same period, the global irrigated area has doubled; accounting for most of the net increase in cultivated land, and world fertilizer use has increased more than fivefold (Drechsel et al., 2015). Driven by the fast expansion of irrigation and fertilizer consumption and the adoption of improved seeds and best management practices, which triggered a significant increase in the yields of major crops, agricultural production has grown between 2.5 and 3 times since the beginning of the 1960s (Drechsel et al., 2015). Irrigated agriculture is dependent on adequate water supply of usable quality. Water quality concerns have often been neglected because good quality water supplies have been plentiful and readily available (Islam et al., 1999). This situation is now changing in many areas. Intensive use of nearly all good quality supplies means that new irrigation projects, and old projects seeking new or supplemental supplies, must rely on lower quality and less desirable sources (Cuena, 1989). The physical and chemical parameters of surface water play a significant role in classifying and assessing water quality. The physico-chemical study reveals quality of water that is suitable for irrigation, drinking and industrial purposes. It is observed that the criteria used in the classification of water for a particular purpose may not be suitable for other purposes. It can be concluded that water suitable for irrigating crop in an area could not be used for growing the same crop in another area whose agro-climatology is different from the former. Scientists do not agree to any water suitability guidelines for irrigating soil and crop under all the condition (Bauder et al., 2006). The suitability of water for irrigation is determined not only by the total amount of the salt present but also by the kind of salt. Various soils and cropping problem develop as the total salt content increases, and special management practices may be required to maintain acceptable crop yields. Water quality for use is judged on the potential severity that can be expected to develop during long term use (Ayers and Wescot, 1985). The study area is under intensive cultivation both during the dry and wet season. The objective of this study therefore, was to assess the quality of water in River Minjibri (Jakara) and its suitability for long term irrigation purpose, by comparing it physico-chemical properties with that of recognized standards of World Health Organization (WHO) and Food and Agriculture Organization (FAO). MATERIALS AND METHODS Location of study area Jakara irrigation project is located in Minjibir Local Government, Kano State, Nigeria. The project is situated in Wasai Village, about 20 km northeast of the state Capital, Kano. It has an area of 416 km 2 and potential irrigation area of 30 ha, out of which less than 25 ha is presently developed and irrigated. Surface irrigation method is practice in the developed area through gravity system. NJAFE VOL. 11 No. 3,

2 Figure 1: A Geographical Map of Minjibir Irrigation Scheme (Source: google maps, 2012). Method of sample collection and analysis A field study was conducted to evaluate the suitability of the water in Minjibir (Jakara) irrigation project for irrigation purpose. Nine (9) sampling points were established over a distance of about 0.6km upstream of the irrigation project along the river course. A total of twenty seven (27) water samples representing three (3) samples from each established point were collected during the cropping period of the peak dry season (March - April, 2013) to minimize error and heterogeneity. Plastic bottles were used for sampling. They were thoroughly cleaned and repeatedly washed and they were also sterilised with methylated spirit. The bottles were kept air tight and labelled properly for identification. Aeration during sampling was avoided by covering the bottle quickly. The temperature of the samples was measured on the spot using thermometer. The samples collected from the study area were carefully transported to the laboratory of the Department of Water Resources Engineering, Ahmadu Bello University Zaria using cooler and were preserved in a refrigerator for analysis. The analyses for the physical and chemical properties of the samples were carried out following the established analytical methods. Na + and K + were determined by flame photometry, Cl - and HCO 3 - by titration method (Jackson, 1967, Page et al., 1982); the Sodium Adsorption Ratio (SAR) was established by the equation using the values obtained for Na +, Ca 2+, Mg 2+ in meq l -1 (Todd, 1980). RESULTS AND DISCUSSION The identified physico-chemical parameters of all the twenty seven (27) samples were shown in Table 4 with their averages, ranges and standard deviations. The temperature plays a significant role in physical, chemical and biological behaviour of aquatic system. The temperature of the water samples were found to be in the range C, with an average temperature of 28 C. The ph of water samples ranged between with an average value of 8.42, which means the water samples is alkaline and is within World Health Organization WHO (1984) and Food and Agriculture Organization FAO (Ayers and Wescot, 1985) impermissible limits of good water quality ( ) from Table 2 and 3. Electrical conductivity is considered to be a rapid and good measure of dissolved solids. Conductivity is an important criterion in determining the suitability of water for irrigation (Gupta et al., 2009). The electrical conductivity of Minjibir Irrigation water ranges between mmhos cm -1 with an average value of 0.93 mmhos cm -1. Electrical conductivity values of all the samples lies in the range of low salinity zone and excellent water quality for irrigation according to both World Health Organization WHO (1984) and Food and Agriculture Organization FAO (1985) ( 0.7), from Table 1, 2 and 3. The carbonates value of both samples was found to be within the ranges of mg l -1 for carbonate and mg l -1 for bicarbonate and with an average mg l -1 and mg l -1 respectively. According to World Health Organization (WHO, 1984) ( mg l -1 ) and Food and Agriculture Organization FAO (1985) ( mg l -1 ) the average carbonate content in the water is within the impermissible limit for irrigation and the average bicarbonate content falls within the unsuitable limit for irrigation ( mg l -1 ), from Tables 2 and 3. The chloride content in Minjibir irrigation project ranges between mg l -1 with an average value of mg l -1 which is above the permissible limit (unsuitable for irrigation) according to World Health Organization WHO (1984) and Food and Agriculture Organization FAO (1985) (>335 mg l -1 ) from Tables 2 and Table 3. The sodium level in Minjibir irrigation project ranges between mg l -1 with an average value of mg l -1 and according to World Health Organization WHO (1984) ( mg l -1 ) the water is good or permissible for irrigation and Food and Agriculture Organization FAO (1985) the water is below the permissible limit and safe for irrigation ( 100 mg l -1 ) from Tables 2 and 3. The Ca 2+ concentrations ranges between mg l -1 with an average value of mg l -1 which lies between the good water quality for irrigation according to World NJAFE VOL. 11 No. 3,

3 Health Organization WHO (1984) ( mg l -1 ) from tables 2 and is above the permissible limit and harmful according to Food and Agriculture Organization FAO (1985) (>400 mg l -1 ) from Tables 3. The Mg +2 concentrations in Minjibir irrigation project ranges between mg l -1 with an average value of mg l -1 which is above the permissible limit and harmful according to World Health Organization WHO (1984) (>150 mg l -1 ) and Food and Agriculture Organization FAO (1985) (>120 mg l -1 ) from Tables 2 and 3. The SAR level in Minjibir irrigation project ranges between mg l -1 with an average value of 2.43 mg l - 1, the water is below the permissible limit but safe according to World Health Organization WHO (1984) ( mg l -1 ) and permissible or good for irrigation according to Food and Agriculture Organization FAO (1985) ( mg l -1 ) from Tables 2 and 3. The main sources of nitrate in water are human and animal waste, industrial effluent, use of fertilizers and chemicals, leaching through drainage system (Gupta et al., 2009). The nitrate level in Minjibir irrigation project ranges between mg l -1 with an average range of mg l -1 and according to World Health Organization WHO (1984) ( mg l -1 ) and Food and Agriculture Organization FAO (1985) the water is good or permissible for irrigation ( mg l -1 ) from Tables 2 and 3. The boron value ranges between mg l -1 with an average value of 0.05 mg l -1 and according to World Health Organization WHO (1984) and Food and Agriculture Organization FAO (1985) the water is good or permissible for irrigation ( mg l -1 ) from Tables 2 and 3. Sulphate is an essential element to the plants. However, where present in excessive amounts is extremely toxic. In Minjibir irrigation project the sulphate value ranges between mg l -1 with an average value of mg l -1 the water lies between the permissible limit according to World Health Organization WHO (1984) ( mg l -1 ), but according to Food and Agriculture Organization FAO (1985) the water is unsuitable for irrigation (>200 mg l -1 ) from Tables 2 and 3. Table 1: General interpretations of EC values Soil EC mmhos cm -1 Total salt content (%) Crop reaction Salt free 0-2 <0.15 Salinity effect negligible, except for more sensitive crops Slightly saline Yield of many crops restricted Moderately saline Only tolerant crops yield Satisfactorily Highly saline >15 >0.65 Only very tolerant crops yield Satisfactorily Source: WHO, 1984 and FAO, 1985 Table 2: Water quality for irrigation (World Health Organization Standards 1984) Parameters Excellent quality Good quality Unsuitable quality ph Electrical conductivity (mmhos cm -1 ) Sulphate (mg l -1 ) Nitrate (mg l -1 ) Bicarbonate (mg l -1 ) Carbonate (mg l -1 ) Magnesium (mg l -1 ) Chloride (mg l -1 ) Calcium (mg l -1 ) Boron (mg l -1 ) Sodium (mg l -1 ) SAR (mmol l -1 ) TDS (mg l -1 ) Phosphate (mg l -1 ) Manganese (mg l -1 ) Iron (mg l -1 ) Source: World Health Organization (WHO) Standards 1984 In Minjibir irrigation project the TDS value ranges between mg l -1 with an average value of mg l -1 which means the water lies between the permissible limit according to World Health Organization WHO (1984) ( mg l -1 ) and Food and Agriculture Organization FAO (1985) ( mg l -1 ) from Tables 2 and 3. CONCLUSION The water samples from Minjibir irrigation were assessed for their quality in terms of their potential for irrigation. The results revealed that the water in the study area have an average temperature of 28 C and is alkaline. The electric conductivity, concentration of chloride, sodium, calcium, magnesium, sulphate, TDS and SAR recorded in the water samples lies in the impermissible limits set by World Health Organization WHO (1984) and Food and Agriculture Organization FAO (1985). The concentration of carbonate, bicarbonate, nitrate and boron are NJAFE VOL. 11 No. 3,

4 unsuitable for irrigation according to World Health Organization WHO (1984) and Food and Agriculture Organization FAO (1985). This research may serve as a preliminary study to provide baseline information that may direct future water quality assessment studies in the study area. RECOMMENDATION Based on the result of this study, the following recommendations are given that the water in river Minjibir need to be treated before using it for irrigation. There is need for periodic irrigation water quality analysis. Table 3: Water quality for irrigation (Food and Agriculture Organization Standards 1985) Parameters Excellent quality Good quality Unsuitable quality ph Electrical conductivity (mmhos cm -1 ) Sulphate (mg l -1 ) Nitrate (mg l -1 ) Bicarbonate (mg l -1 ) Carbonate (mg l -1 ) Magnesium (mg l -1 ) Chloride (mg l -1 ) Calcium (mg l -1 ) Boron (mg l -1 ) Sodium (mg l -1 ) SAR (mmol l -1 ) TDS (mg l -1 ) Phosphate (mg l -1 ) Manganese (mg l -1 ) Iron (mg l -1 ) Source: Ayers and Westcot, 1985 REFERENCES Ayers, R. S. and Westcot, D. W Water quality for agriculture, Irrigation and Drainage Paper 29, FAO Organisation of the United Nations Review 1. Bauder, T. A., Waskom, R. M., Sutherland, P. L. and Devis, J. D Assessing the suitability of water (Quality) for Irrigation - Salinity and Sodium. Pp3-5. Ceuna, R. H Irrigation System Design. Prentice Hall, Eastern Limited, New Delhi, India. Pp Drechsel, P., Heffer, P., Magen, H., Mikkelsen, R., Singh, H., Wichelns, D Managing water and nutrients to ensure global food security, while sustaining ecosystem services. In: Drechsel, P., Heffer, P., Magen, H., Mikkelsen, R., Wichelns, D. (eds). Managing water and fertilizer for sustainable Agricultural intensification. IFA, IWMI, IPNI, and IPI publication. Pp 1-8 Gupta, P., Ranjeeta, C., and Monica, V Assessment of water quality of Kerwa and Kaliasote rivers at Bhopal district for irrigation purpose. International Journal of Theoretical & Applied Sciences, 1(2): Islam, M. S., Hassan, M. Q. and Shamsad, S. Z. K. M Ground water quality and hydrochemistry of Kushtia District, Bangladesh Journal Asiat. Soc. Bangladash Sci. 25(1):1-11 Jackson, M. L Soil Chemical analysis. Prentice Hall Inc. Englewood Cliffs, NJ. USA. Pp Todd, C Ground Water Hydrology. 2 nd ed., John Wiley and Sons Inc. New York, USA. Pp World Health Organization (WHO) Guidelines for Irrigation Water Quality, Vol.1, recommendations, Geneva, p.130. NJAFE VOL. 11 No. 3,

5 Table 4: Results of the physical and chemical properties of the irrigation water samples of the River Minjibir (Jakara) Irrigation Scheme Sampling point Temperature ph EC W (mmhos NO - (mg l -1 ) SO 4 B (mg l -1 ) Na + Mg 2+ CO 2-3 (mg l -1 ) HCO 3 Ca 2+ Cl - (mg l -1 ) SAR (mg l -1 ) TDS (mg l -1 ) ( O C) cm -1 ) (mg l -1 ) (mg l -1 ) (mg l -1 ) (mg l -1 ) (mg l -1 ) UP Stream Up Stream Mid Stream Mid Stream Down Stream _ Down Stream _ Up Stream Up Stream Mid Stream Mid Stream Down Stream Down Stream Up Stream Up Stream Mid Stream Mid Stream Down Stream Down Stream Average Range S.D NJAFE VOL. 11 No. 3,