Evaluation of Crop Water Requirements of Maize in Nigeria Using FAO Penman-Monteith Model
No Thumbnail Available
Date
2018
Journal Title
Journal ISSN
Volume Title
Publisher
Nigerian Journal of Hydrological Science
Abstract
Irrigation practices are best done by estimating the crop water requirement in order to avoid over or under irrigation which may negatively affect crop yields. In this study, weather data spanned (1995-2015) were collected and analysed for eighteen weather stations in Nigeria. The data obtained include minimum and maximum temperature (oC), relative humidity (%), wind speed (km/day), sunshine (hr /day) and radiation (MJ/m2/day). The FAO Penman-Monteith model was used to compute the mean monthly reference evapotranspiration (ETo). The mean monthly ETo estimated for each weather station by FAO Penman-Monteith model were multiplied by the average crop coefficient (Kc) of Maize (0.60) to determine the crop water requirements. The results of the analyses showed that the mean monthly average crop water requirements (ETc) estimated for the six zones are 5.67, 6.95, 4.48, 3.30, 0.94, and 1.99 mm/day. The graphical relationship of mean monthly crop evapotranspiration (ETc) values across the period of record shows that ETc estimates at North-East ranked 2nd with the highest values from 1996 to 2000 and North-West also have the highest values of ETc in 1996, 2003, 2006, 2009, 2011, 2012, 2013 and 2015. The ETc estimates at North-Central ranked 3rd with highest value in 2014 and ETc estimates at South East and South West are in closest agreement followed by South-South ETc estimates which has the lowest ETc value except in 2002 that South-West has the lowest ETc value. Therefore, this study will be useful to the agricultural water management and regional water resources planning.
Description
Keywords
Irrigation, Evapotranspiration, Crop water requirement, Maize, Crop coefficient