Analysis of soil properties on irrigated lands along Farin Ruwa, Mada and Antau Rivers in Northern Nasarawa State, Nigeria.

The quality of water used for irrigation if not properly managed, may result in the build-up of ionic substances at levels to reduce the productive capacity of soils and yields of many crops. This study therefore analysed soil properties on irrigated lands along Rivers Farin Ruwa, Mada and Antau in Northern Nasarawa State, Nigeria. Data for this study involved collection of 60 water samples and 24 soil samples from both dry and rainy seasons respectively. Both the water and soil samples were analysed for the concentrations of the physico-chemical properties affecting irrigation such as pH, sodium, potassium, calcium magnesium, phosphates, nitrates, chloride, nitrogen%, soil texture, carbonate and bicarbonate, trace elements such as boron, lead, iron and salinity caused by soluble salts. Indices such as Sodium Adsorption Ratio (SAR), Residual Sodium Carbonate (RSC) and Exchangeable Sodium Percent (ESP) were employed in determining sodium hazards of the irrigation water on soils of the study area. Results from the study showed a mean high value of electrical conductivity on soils along Farin Ruwa River ranging from 202-490uS/cm for the seasons. The Sodium Adsorption Ratio recorded for the rivers was between 0.27-0.45 and was within the 0-3 considered suitable with no problem for irrigation. Residual Sodium Carbonate (RSC) was between -29.8-17.0 due to the high values of calcium and magnesium recorded for this study. Though pH was generally alkaline for the water, it was acidic (4.92-6.12) for the soils. Exchangeable sodium percent was low for the soils ranging between 2.4 to 5.1%. The concentration of iron in the soils was from1.7 mg/kg to 2.2 mg/kg. Phosphate was from 2.0 mg/kg to 3.9 mg/kg while nitrate was between 0.05 mg/kg and 0.09 mg/kg. The results of soils from irrigated lands along the rivers covered by this study were generally low for most of the properties except for pH which was acidic for all the soils along the irrigated fields and the high salinity observed for soils along River Farin Ruwa. The study therefore recommends that there is the need to raise the pH of the soils by increasing the application of organic matter and fertilizers and increasing the frequency of irrigation water on soils along Farin Ruwa River to leach the high salts concentration observed for the soils.