Rainfall variability and agricultural production in the Lower River Region (Gambia): Case of rice and maize

In the Gambia, particularly in the Lower River Region, agricultural production in mt has increased over the past two decades despite variability in rainfall conditions. In response to this finding, the study aims to analyze the evolution of rice and maize production in the Lower River Region, and to determine, in particular, the dependence or independence of each production on rainfall and cultivated areas. To do this, data on production in mt and hectare cultivated areas of rice and maize between 1981-2016, and precipitation data over the same period are used. These data are derived respectively at the level of the Gambia Department of Agriculture Planning Services and the Department of Water Resources. Their treatment was based on statistical data, including descriptive statistics, Pearson correlation, and simple linear regression. The calculation of the simple linear regression at the p<0.05 threshold indicated a non-significant relationship between rice and rainfall. In other words, rice does not depend on rainfall. This is not the case for corn, where the linear regression equation was found to be significant with b=0.395, (1,34)=-0.606, p<0.05. On the other hand, with respect to cultivated areas, the results show that rice production is highly dependent on it. The linear regression equation was found to be significant with b=0.679, (1,34)=2,485, p<0.05. Adjusted R² is 44.5%. It is even more significant for corn with an adjusted R² of 100%.