Changing Pattern of Rainfall Amount and Raindays in Samaru, Northern Nigeria and Their Implications on Crop Production

The rainfall amount and number of rainy days determines the length of growing season, which equally determines the types of crops to be planted in a particular region. This study analyzed the pattern of rainfall in Samaru Zaria, Kaduna State, Northern part of Nigeria from 1961-2017 using data collected from the Institute for Agricultural Research Samaru, Zaria. The result from this research reveals that an inverse relationship exists between the amount of rainfall and the rainy days. Hence, the higher the rainfall amount the lower the rainy days and vice versa. This is attributed to the current change in climate which increases the intensity of annual rainfall but shortens the duration of the rainy days. The equations generated for amount of rainfall pattern was (y= 3.162x - 5270.9) and number of rainy days was obtained as (y = -0.172x + 417.85). As expected, the months of November to March had the lowest mean rainy days (MRDs) <1 day. As a recurrent pattern for the period of study, the onset of appreciable rainy days was observed in the month of April and the number of rainy days increased steadily to reach its peak in August and a sharp decline in October. From the obtained data, the onset and cessation of rainfall could be predicted to fall towards the end of April and September respectively.