effect of irrigation on soil properties in jakara kano, nigeria

soil samples from the jakara irrigation project site were evaluated with respect to possible degradation caused by irrigation. most of the soils were neutral to alkaline with ph values ranging between 6.58 + 0.04 and 10.45 + 0.03. the electrical conductivity ranged from 0.3 + 0.01 to 75.2 + 0.06 dsm-1 which implies low to very high salinity. the concentrations of the exchangeable cations in the soils follow the order na+ > mg2+ > ca2+ > k+ with respective concentrations of 8.70 + 0.4 to 187.8 + 0.5 cmolckg-1, 1.06 + 0.05 to 5.49 + 0.05 cmolckg-1, 0 to 15 + 0.05 cmolckg-1 and 0.36 + 0.02 to 2.73 + 0.05 cmolckg-1. it was noted that na+, a non-essential cation is dominant in the soil samples. the results showed esp values much greater than 15% for all the soil samples studied which implies high soil degradation. the available p and c:n ratios ranged from 1.0 + 0.01 to 4.9 + 0.06?gg-1 and 0.2 to 11.0 respectively while the available k ranged from 8 + 0.02 to 138 + 6?gg-1 . it was observed that less than 17% of the total k was available for plant uptake. the soil was noted to be clayey in nature with cec values ranging between 20 + 2 and 86 + 5 cmolckg-1 with a ranking model indicating low fertility indices.