Adoption of Soil Health Cards, Fertiliser Use Efficiency, and Crop Yield Outcomes Among Smallholder Farmers

The Soil Health Card (SHC) scheme, launched by the Government of India in February 2015 with the objective of providing every farmer in the country with periodic soil nutrient assessments and site-specific fertiliser recommendations, represents the most ambitious soil information programme in India’s agricultural policy history. Despite nationwide issuance of over 22 crore SHCs across three scheme cycles, adoption of the scheme’s fertiliser recommendations by smallholder farmers has been inconsistent, and the relationship between SHC adoption and measurable improvements in soil health indicators, fertiliser use efficiency, and crop yield has been documented only in fragmented, geographically narrow studies that do not account for district-level variation in soil type, cropping system diversity, extension service quality, and farmer literacy levels.This study addresses this gap through a district-level analysis integrating IARI soil testing database records with a structured farm household survey of smallholder farmers across ten districts of Tamil Nadu, comparing soil nutrient status, fertiliser application patterns, and crop yield outcomes between SHC adopters and matched non-adopters using propensity score matching to control for selection bias. The analysis assesses the dose-response relationship between SHC recommendation compliance and yield improvement, identifies district-level and farmer-level characteristics that predict adoption and recommendation compliance, and examines whether the scheme’s benefit varies across the five major soil nutrient dimensions that Tamil Nadu’s agroclimatic zones are characterised by — findings that can inform the SHC scheme’s restructuring under the PM-KISAN digital agriculture platform.