Comparative Assessment of Soil Fertility in Irrigated and Rainfed Farmlands Using Exchangeable Cations and Cation Exchange Capacity in Kura, Kano State

The productivity of all farming methods is largely dependent on the soil's fertility, and soil's ability to provide nutrients to crops is the most common way that soil fertility is characterized. The aim of this study was to compare the Exchangeable Cations and Cations Exchange Capacity (CEC) between selected irrigated and rain-fed farmlands of Kura Local Government, Kano State. Soil samples were collected from selected irrigated and rain-fed farming plots at a depth (0-20cm). The BaCl2 Compulsive Exchange method was used to assess the Exchangeable Cations and Cations Exchange Capacity (CEC) samples. The study revealed that the soil samples from irrigated plots have medium to high Ca (2.60-4.05Cmol/kg), Mg (1.625-2.250Cmol/kg), K (0.534-0.897Cmol/kg), and Al (0.094-0.367Cmol/kg) concentrations. Rain-fed plots samples analyzed also had medium to high Ca (3.00-4.90Cmol/kg), Mg (1.625-2.250Cmol/kg), K (0.240-0.897Cmol/kg) and Al (0.094-0.367Cmol/kg) concentrations. The irrigated soil samples had low to medium CEC (5.3 cmol/kg to 7.30 cmol/kg), while the rain-fed soil samples had medium CEC (6.07 cmol/kg to 8.90 cmol/kg). The mean values of the soil parameters analyzed were obtained, and the results were compared with the standard critical limits. The results indicate that soil samples from rain-fed farmlands have higher levels of Exchangeable Cations and Cation Exchange Capacity (CEC), except for potassium, which was found to be higher in the samples from irrigated farmlands. Statistical analysis revealed significant differences (p<0.05) between the irrigated and rain-fed samples mean of Magnesium Cation, while the analysis revealed insignificant differences (p>0.05) between the means of Calcium, Potassium, Aluminium, and CEC. However, both the values fell within the range of fertile soil. These findings fit with the existing literature on semi-arid West Africa, stressing the importance of CEC-driven approaches and tailored strategies for increasing agricultural productivity. The research supports the use of combined organic and inorganic fertilizers, referred to as integrated nutrient management, to maintain soil fertility in both systems. Regular testing of the soil is encouraged in order to monitor the nutrients and modify the amendments accordingly.