Authors : Christopher O. Akinbile and Kola Ogedengbe
Abstract: Two models, Davis and Fok and Bishop were explored to determine their furrow advance prediction accuracy in comparison with actual field observation in Nigeria. An expression that relates the intake rate with accumulated intake time using Kostiakov-lewis equation for field observation was found to be Y = 0.71t 0.76 Correlation coefficients between actual field observation and Davis model ranged from 0.99 to 0.81 and from 0.85 to 0.98 for Fok and Bishop model which indicated that the latter is more applicable as the stream size increases. Their generally high coefficient values indicated their usefulness in prediction. The field data analyzed and fitted by least square method of curve fitting to yield equation of the type X = a(t)b for a given irrigation condition. The equations relating the advance length and time at discharge (Q) 1.2 litres/sec and 0.6% slope are X = 4.8t 0.3 (Davis), X = 2.6 t0.57 (Fok and Bishop) and X = 2.5t0.55 (field observation) while at discharge (Q) 2 litres / sec and the same slope, X = 6.2t0.45 (Davis), X = 3.2t0.59 (Fok and Bishop) and X = 3.0t0.56 (field observation). Fok and Bishop model thus affords a more accurate prediction of the advance wetting front, having the least deviation within the context of this study.
Christopher O. Akinbile and Kola Ogedengbe , 2006. On the Dynamics of Advance Wetting Front in Furrow Irrigation in Nigeria. Agricultural Journal, 1: 221-229.