Estimation of Water Requirements of Selected Field Crops in South- West and South- East Nigeria

Abstract: Estimation of crop water requirement of some selected field crops was carried out based on twenty-one years and ten years meteorological data at Abeokuta and Umudike respectively. These crops include as maize, pepper and tomato. Reference evapotranspiration was calculated using BlaneyCriddle model for Abeokuta and Penman Model for Umudike. The result obtained showed that the seasonal crop evapotranspiration (ETcrop) for maize, pepper and tomato were 378.33, 558.51 and 505.92mm/month in Abeokuta and 353.13, 130.97, and 464.82mm/month in Umudike. Effective rainfall (ER) was lower than the water requirement in the months of May and June for maize cultivation in Abeokuta, similarly, effective rainfall was lower that the water requirement in the months of March, April, May and August for pepper in Abeokuta. This indicates that supplemental irrigation was needed during these months. Irrigation water requirement (IR) was 11.73mm for soils of Umudike. The study also established that pepper and maize could be grown conveniently during their growing season without supplemental irrigation in Umudike. However, the sufficient water availability for crops in Umudike during their growing season will produce good yields and good quality crops compared to Abeokuta.