Assessment of Precision Land Levelling Benefits for Water Use Efficiency in Smallholder Rice Paddy Fields in Kebbi State

This study assesses the benefits of precision land levelling on water use efficiency and rice paddy yield in smallholder irrigated rice fields in Kebbi State, North West Nigeria. Land levelling, the grading of paddy field surfaces to uniform elevation, is a fundamental irrigation management practice that significantly affects water distribution uniformity and irrigation efficiency. Unlevelled paddy fields experience uneven water distribution, with ponding in low areas and dry conditions in elevated zones that collectively reduce water use efficiency and yield uniformity. This study uses a before-after comparison design, measuring water use efficiency and rice yield on 30 paddy plots before and after precision laser-guided levelling treatment at Argungu and Jega irrigated areas. Field topographic surveys use a total station instrument. Water application volumes are measured using water meters at plot inlets for two growing seasons. Rice yield is assessed by harvesting six representative sub-plots per field. Findings reveal that precision levelling reduces field elevation range from a pre-levelling average of 14.2 centimetres to 2.8 centimetres post-levelling. Irrigation water application is reduced by 28 percent with no significant yield reduction. Rice yield uniformity improves significantly, with spatial coefficient of variation declining from 31 to 12 percent. The study concludes that precision land levelling generates significant water saving and yield uniformity benefits for Kebbi State smallholder rice paddy farmers. It recommends a state-supported precision levelling service using hired laser levelling equipment made available to farmer cooperative groups at subsidised rates.

Keywords: land levelling, water use efficiency, rice paddy, Kebbi State, laser levelling.