A Sahelian country, Niger has an arid climate. Socioeconomic development is essentially based on agriculture. This activity employs more than 80% of the working population in rural areas. Unfortunately, it is hampered by the scarcity and irregularity of water leading to a drop in crop yields and a risk of food insecurity. In this context, irrigation has established itself as an essential path for the sustainable development of agriculture in Niger. The objective of this study is the tensiometric monitoring of the evolution of soil water reserve. To achieve this objective, a device aimed at determining the reading on the tensiometer from which it is necessary to trigger the irrigation so that the crop does not suffer from water deficit, is installed on a clayey-sandy soil in the market gardening site of Birni N'Konni. The results led to the conclusion that the water supply is renewed each time the voltages observed are between 16 and 22 centibars. It should be noted that 24 hours after adding water, the voltages are between 05 and 06 centibars.