Frontier Analysis of Agricultural Water Use Efficiency in Nigerian Irrigated Agriculture: Stochastic Frontier and Data Envelopment Analysis

This study applies stochastic frontier analysis and data envelopment analysis to measure and explain water use efficiency in Nigerian irrigated agriculture, contributing original methodological and empirical insights to a critically underresearched dimension of agricultural resource economics in the country. Water scarcity is an emerging constraint on Nigerian agricultural productivity, particularly in the North West and North Central zones where irrigation is expanding rapidly. Understanding how efficiently water resources are used in existing irrigation schemes is essential for sustainable irrigation expansion policy. This study uses farm-level data from 380 irrigated farming households in four major irrigation schemes across Sokoto, Kebbi, Kano, and Niger States, collected through a specially designed irrigation economics survey. A stochastic frontier water production function is estimated alongside a DEA water efficiency model. Both approaches compute farm-level water use efficiency scores and identify determinants of efficiency variation through second-stage regression. Determinants assessed include irrigation method, crop type, farmer experience, extension contact, water user association membership, and water fee payment compliance. Findings reveal average water use efficiency of 0.67 using SFA and 0.71 using DEA, indicating significant scope for improved water productivity. Water user association membership is the strongest positive efficiency predictor, operating through improved water delivery scheduling and conflict resolution. The study contributes an original comparative SFA-DEA water efficiency framework for Nigeria and recommends water user association strengthening and deficit irrigation technique extension.

Keywords: water use efficiency, irrigated agriculture, stochastic frontier, Nigeria, data envelopment analysis.