Climatic Water Balance Over Two Climatic Periods and Effect on Consumptive Water Need of Selected Crops in the Chad Basin, Nigeria

Abstract

Agriculture is a critical part of Nigeria’s economy as it employs a large proportion of the population. However, climate change is a threat to agriculture in many parts of Nigeria especially the north-eastern part where the Lake Chad basin is a prominent victim. Yet, the Lake Chad basin is crucial to food security in Nigeria as most of the grains are grown there. Thus, prudent management of water resources and agricultural planning is required to ensure the sustainability of crop production in the basin. This study applied the Thornthwaite water balance model to compute the water balance of select crops in the basin to devise a better farming practice based on the findings. The study period was divided into two, the base period (1945–1979) and the second period (period of change 1980–2014). The findings show that there is a significant change or variability in climate between the two periods. However, the change is higher in Nguru which may be due to its higher latitudinal location and the desert encroachment due to poor land-use management. However, with the proposed bi-annual cropping of the select crops, it is possible to have double seasons of planting in the study area. The first season will be from May–September and the second from October–February. Since the water need of these crops is not so demanding, the crops can be grown twice with prudent water management via rainwater harvesting and minimal groundwater withdrawal. Further studies are suggested to work out the irrigation schedule for the different crops to minimise waste and losses due to over-irrigation. Hence, it is recommended that improved seed crops with very short growing cycle and/or drought-tolerant species as well as developing all-year-round planning is a panacea to human and environmental concerns in the basin.