Rainfall variability and crop production in the North-western semi-arid zone of Nigeria

摘要

This research work examined the implications of rainfall variability on some major food crops of the semi - arid region of northern Nigeria in a changing climate. Fifty years of daily rainfall data (1963 - 2012) were collected from the Meteorological unit of the Institute for Agricultural Research, Ahmadu Bello University Zaria and the data were processed using VISUAL-BASIC.NET programme. The concept developed by Ashok Raj (1979), "onset of effective monsoon and dry spells” was adopted in the present study. Grain yield data were also sourced from states’ agricultural development projects. Correlation analysis was employed to assess the relationship between crop yield and dry spells. The result indicated about 10 days shift from the normal planting period. The result also showed negative relationship which is significant at 1% level of confidence for sorghum and maize and significant at 5% level of confidence for cowpea and rice. The smallholder farmers and policy makers were advised on the implications of the reduced and erratic rainfall pattern to agricultural productivity and science-based mitigation and adaptation strategies (such as water conservation techniques, genetic improvement of crops and improved irrigation techniques, water harvesting, etc.) were suggested.