Abstract

Water availability for Abeokuta, a sub humid part of Nigeria was determined using Blaney-Criddle method and applying 21 years of data on precipitation, sunshine hours, wind speed, minimum and maximum temperature and relative humidity. The water need of certain crops within the study area such as cotton, maize, pepper and tomato were derived. This was done by calculating the evapo-transpiration values for each month within the study period, estimating the growth stages of the crops, the crop factor for each growth stage, the crop factor for each of the month during the growing season, calculating the daily crop water need and the monthly crop water need. Result showed that the crop water need for the growing season of maize is 375 mm. It also showed that maize can be planted conveniently within its growing season without irrigation in Abeokuta. The result obtained for cotton showed that the crop water need for the growing season is 588 mm and that the plant could be planted during its season in the study area with irrigation. The result obtained for tomato showed that the crop water need for the growing season is 498 mm and that it can be planted conveniently within its growing season without irrigation in Abeokuta. The result obtained for pepper showed that the crop water need required for the growing season is 513 mm. It also showed that pepper can be planted conveniently within its growing season without irrigation in Abeokuta.