Evaluation of the Suitability of Water in Rivers for Irrigation in Northern Nasarawa State, Nigeria
1Samaila Kunden Ishaya, & 2Kwarfwang Kevin Jack
1Department of Geography, Nasarawa State University Keffi.
2Department of Geography Plateau State University, Bokkos
Email: ikunden@yahoo.com
ABSTRACT
Water high in both the physical and chemical properties when used directly for irrigation is likely to result in the built-up of substances at levels to affect the productive capacity of the soil and lower crop yields. This
study evaluates the suitability of water in rivers for irrigation in Northern Nasarawa State, Nigeria. Data for this study involved the collection of a total of 60 water samples from the three rivers (FarinRuwa, Mada and Antau) for rainy and dry seasons. Standard laboratory methods were used to determine pH, electrical conductivity, total dissolved solids, sodium, potassium, calcium, magnesium, chloride, phosphates, nitrates,
carbonates and bicarbonates, boron, lead and iron. The results show the electrical conductivity of the rivers ranged from 44.5 for River Mada rainy season to 280.9uS/cm for River Antau dry season, pH was between 7.13 for River Antau dry season to 7.50 for river Antau rainy season. Sodium adsorption ratio was between 0.25 for River Mada dry season to 0.45 for River Antau dry season. Residual sodium carbonate was from -29.8
for River Antau dry season to -17.0 meq.l for river Mada dry season. Bicarbonate was highest 3.13 for River Antau dry season and lowest for River Mada rainy season. Boron was between 0.23 for River FarinRuwa
rainy season to 0.52 for River Antau dry season. The results showed most variables of water from the rivers for the seasons were generally low and fall within the limits considered safe for irrigation by FAO, (1994) and
Ayers and Westcots (1985). The suitability of the water was rated class 1 suitable 1 which indicates the water being excellent for irrigation without undesirable accumulation of dissolved salts, sodium and toxic metals at
intensities to impact negatively on the soil and yields of crops. The study recommends that Farmers should utilize these rivers for dry season farming to boost food production and that both irrigation and rain-fed
agriculture should be practiced on lands along the rivers as the water quality of the rivers is suitable for irrigation and have not impacted negatively on the soils. Keywords: Irrigation, suitability, water quality, salinity and classification.
