Adaptability of Infiltration Equations to the Soils of the Permanent Site Farm of the Federal University of Technology, Minna, in the Guinea Savannah Zone of Nigeria

Abstract

Infiltration refers to water moving into soil from rainfall or irrigation and is the first stage of water movement in the soil. Infiltration rate usually shows a sharp decline with time from the start of the application of water. The initial soil moisture content at any given time was considered to influence the initial rate and total amount of infiltration, both decreasing as the soil moisture content rises. The infiltrometer rings were placed at random distance from each other and the measurement was taken to the nearest centimeter. Water from jerry-cans was poured into the infiltrometer compartments simultaneously and as quickly as possible. As soon as the jerry-cans were emptied, the water level from the inner cylinder was read from the float (rule) and the local time was also noted. Repeated readings were taken at intervals of 0, 1, 2, 5, 10, 15, 20, 30, 45, 60, 75, 90, 100 and 120 minutes. The percent count of R square values from the curve fittings from which it could be observed that the Kostiakov’s equation has the best fit with 99.35% for fallowed land and 98.79% for cultivated land. Although Philip’s equation had a R square value of 53.10% for cultivated land and 55.22% for fallowed land, when compared with the R square value of Kostiakov’s, it was far lower, since Philip’s model is limited to swelling homogenous soils and for vertical flow while Kostiakov’s equation has no limitation. It is also known to apply to the three dimensional flow.