Water Use Efficiency and Productivity of Irrigated Rice Cultivation in Nigeria: An Application of the Stochastic Frontier Approach

Abstract

In the face of declining water resources and low agricultural water productivity, it is vital to increase agricultural production efficiency and efficiency of water usage. The efficacy of irrigating rice fields in Nigeria is evaluated here using a stochastic frontier analysis. This is a parametric frontier that is assumed to have half-normal distribution, allowing the model to be separated from normal errors in a composite error model. Samples of 382 surveys were used in the study; out of the total number, 361 surveys were retrieved and used for the analysis. The analytical tools used in the study are: gross margin, water productivity analysis, and stochastic frontier approach. The results indicate an average yield of 4.69 and 4.94 tons/hectare, and net farm income of $415 and $364 for the farmers using canal irrigation and farmers using tube wells, respectively. The results also showed physical and economic water productivity of 0.51 kg/m3 and $0.11/m3 for canal water users, and 0.568 kg/m3 and $0.10/m3 for tube well users. The canal water users had a mean irrigation water use efficiency of 0.76, compared to 0.70 for the tube well users. The study recommends that effective extension services and their coverage be enhanced to provide adequate training to rice farmers on water use efficiency and the transfer of innovations and farming technologies to farmers.