Rainfall variability and the impact on maize and rice yields in north – central Nigeria

Rainfall variability in terms of amount, distribution (spatial, seasonal and diurnal), intensity and frequency of rainy days influence crop production and yield. This paper examined rainfall temporal trend inter-annual and spatial distribution and the implication of mean annual rainfall on maize and rice yield in North – Central Geopolitical Region of Nigeria. Daily rainfall records of thirty years period (1987 – 2016) at six stations in the region, namely; Abuja, Ilorin, Jos, Lokoja, Makurdi and Minna were obtained from the archive of the Nigerian Meteorological Agency (NiMet), Abuja and maize and rice yield for the period 1994 – 2016 obtained from the Bureau of Statistics of Nigeria were used for the study. The rainfall data were subjected to statistical analysis using descriptive analysis. Mann-Kendal test and Kriging method were used for the spatio–temporal rainfall distribution while the impact of rainfall amount on maize and rice yields was investigated using regression analysis. The annual rainfall amount experienced in study area was between 1100 mm and 1700 mm. Out of the six stations studied; only Abuja indicated statistically significant increased trend while the other five stations in the region showed no significant trend. Rainfall distribution in the region is largely influence by the Jos Plateau rather than Latitudes or Longitude. Generally, rainfall influences maize and rice yield positively but at varying degree from station to stationKeywords: Rainfall variability, Trend, Distribution, Impact