The thesis is structured into three interconnected chapters that jointly explore the effects of the digital extension service for agriculture on crop yields with a focus on India under the umbrella of Regional Science and Agricultural Economics. In the initial chapter, we identify clusters of districts with high and low seasonal yield performances for the major food grains in India: paddy, wheat, and millets. In the following chapter, we examine the impact of access to agricultural information from India's farmers (\textit{Kisan}) call center (KCC) on seasonal paddy and wheat yields at the district level, focusing on selected ten States representing India. Finally, in the third chapter, we evaluate the influence of mobile-based agricultural information services (KCC) on the state of regional convergences of seasonal paddy yields, taking into account the district-level technical efficiency of seasonal paddy cultivation (β-convergence) and the trend of seasonal paddy yield outcomes (σ-convergence).