A Measurement of Drought - Crop Relationship in Northern Nigeria

Abstract

The relationship between drought magnitude and crop yield was examined on 5 crops in 5 states of northern Nigeria. The states covered include Sokoto, Kaduna, Kano, Borno and Bauchi, while the crops investigated were Maize, Millet, Sorghum, Groundnuts and Cowpea, Secondary data on rainfall and crop yield in the selected locations were obtained for a period of 13 to 30 years from Agricultural Development Programme Offices (ADPs) of the states and Office of the Federal Bureau for Statistics. The rainfall data was subjected to the standardized Precipitation Index (SPI) analytical technique to established drought occurrences magnitude. The inferential statistical techniques of correlation and regression test were carried out on the crop yield and 12 months SPI values generated covering the same period. Results obtained shows that for Sokoto. Maize, Sorghum and Cowpea are affected positively by SPI values. This simply means that SPI values with high values of negative sign will affect the yield of Maize, Sorghum and Cowpea negatively in the location. Another major finding reveals that drought magnitude exhibit very little effect on the yield of Groundnuts in Sokoto and Kaduna states. Both findings were significant at the 0.05% confidence level. The implication of findings for crop cultivation in northern Nigeria was thoroughly discussed and appropriate recommendations proffered. The research concludes that drought occurrences in the studied states were mostly "Near Normal" droughts of very low magnitude (0.00 to -0.99) and they hardly occurred back to thus its effect on crop - water need is quite minimal