Impact of Climate Variability on Irrigation Water Needs and Irrigation Schedules of Maize and Cucumber in Aba, Abia State

In an attempt to address the discrepancies in the food production and population growth rates in Nigeria, this study estimated the irrigation water requirements of maize and cucumber in Aba, Abia State. Meteorological parameters (rainfall, minimum and maximum temperature, relative humidity, wind speed, sunshine hours) were collected from NiMet Abuja for 20 years (2000 to 2020). CROPWAT version 8.0 was applied to determine the Crop ETo and irrigation schedule of maize and cucumber. The hypothesis: Impact of climate variability does not influence irrigation of maize and cucumber was tested using Pearson correlation coefficient. The result shows that during the early and late planting season of maize, the crop water used are 338.6mm and 276.6mm, effective rainfall 478.8mm and 782.8mm and the total rainfall 740.0mm and 1028.6mm. For cucumber, the water used by the crop is 334.9mm and 285.8mm, and effective rainfall 332.6mm and 663.9mm. There was no irrigation schedule for maize and cucumber during the early and late plating seasons. It shows that water requirement for maize and cucumber was enough during the seasons. The highest crop ETo and temperature was in the month of March (4.57mm/day) and January (33.7°C). The study also reveals that the impact of climate change on irrigation water need at 0.05 significant level is IR=192.811-0.089(TR). The result shows a negative slope (-0.089), which means a negative relationship between Irrigation required and total rainfall over the 20 years period. This indicates that as rainfall increases, irrigation required decreases. The study therefore, suggests that maize and cucumber should be planted in Aba all year round; since there is enough rainfall for the crop

Decadal Assessment and Distribution of Rainfall Anomaly Index (1991 – 2020) for Benin City, Edo State, Nigeria

This study was designed to provide valuable insight into the temporal patterns of rainfall in Benin City, Edo State, Nigeria using rainfall data from 1991 – 2020 (30 years) collected from Nigerian Meteorological Agency (NIMET), airport station, Benin City. The data were assessed based on 10 years interval (decade) identified as decadal A (1991-2000), decadal B (2001-2010) and decadal C (2011-2020). The data was analysed descriptively using charts and graphs. Also, Rainfall Anomaly Index (RAI) was determined for each decadal. Findings from the study reveal that rainfall pattern changes significantly based on statistics for each decadal. In decadal A, rainfall usually began in the month of July to October, June to September in decadal B while May to September in decadal C with rainfall going above the annual precipitation (2679 mm) for the City. The rainfall anomaly over the city revealed that there was a composite nature in which some dry years were mixed with wet years and vice versa and this occurred in all decades. RAI revealed that decadal C recorded the highest number of years (7) of intense rainfall compared to decadal A and B. The trend for the average annual rainfall showed a significant trend based on the decade. The average annual rainfall increased with time (decade) as the trend rose from 1886.9 mm in decade A to 1890.0mm in decade B and 2078.8 mm in decade C. The year of greatest positive value was 2016 (decadal C), with an average RAI of 6.53 classified as extremely humid. Based on these findings, the study concludes that the climate in Benin City has significantly changed