ABSTRACT Given the challenges posed by climate change and the scarcity of water, it is essential to adopt sustainable irrigation practices that do not compromise crop yields. Research studies are crucial to determine the optimal deficit soil moisture levels to be maintained for cultivation in different soil types. This study examines the response of maize grown on loamy sand soil under different water deficit moisture contents by monitoring the variation of the crop growth in terms of the leaf area index, biomass weight, root depth and yield. The daily soil moisture is measured to understand the actual evapotranspiration from the study plots. From the experiments, the optimal moisture content identified is 13%, and the plot maintained at this moisture content has shown the highest evapotranspiration, yield and biomass. The yield response factor of the maize grown in water deficit conditions is also observed to be very close to the value reported by FAO. As expected, the yield response factor is found to be sensitive to water stress. The deficit irrigation at the optimal moisture content of 13% could be recommended for maize cultivation in loamy sand soil in North Indian climatic conditions. Such considerations will be vital for achieving sustainable irrigation goals.