Which government initiative primarily aims to enhance land productivity by encouraging the judicious application of crop nutrients based on soil testing?

The correct answer is Soil Health Card Scheme.

Step 1: Concept and Purpose of the Initiative
The primary goal of the initiative mentioned in the question is to assess the fertility status of agricultural soil through systematic testing and to advise farmers on the balanced use of plant nutrients. By addressing nutrient deficiencies and preventing the overuse of chemical fertilizers, the scheme aims to improve overall land productivity and lower cultivation costs for farmers.

Step 2: Key Features of the Soil Health Card Scheme
1. Soil Testing: Launched by the Government of India in February 2015, the Soil Health Card (SHC) scheme collects soil samples from farmers' fields and tests them across 12 crucial parameters, including macro-nutrients (N, P, K), micro-nutrients (Zn, Fe, Cu, Mn, Bo), secondary nutrients (S), and physical parameters (pH, EC, OC).
2. Issuance of Cards: A customized Soil Health Card is issued to each farmer detailing the specific nutrient status of their field along with dosage recommendations for various crops.
3. Judicious Application: The tailored recommendations enable farmers to apply fertilizers judiciously, avoiding unnecessary expenditure and preserving long-term soil health.

Step 3: Overview of Other Initiatives
• Pradhan Mantri Krishi Sinchayee Yojana (PMKSY): Aimed at enhancing access to irrigation ("Har Khet Ko Pani") and improving water utilization efficiency ("More Crop Per Drop").
• Pradhan Mantri Fasal Bima Yojana (PMFBY): A crop insurance scheme aimed at providing financial support to farmers suffering crop loss/damage due to natural calamities.
• Paramparagat Krishi Vikas Yojana (PKVY): Focuses on promoting organic farming practices through a cluster-based approach.

Therefore, the government initiative that specifically encourages the judicious application of crop nutrients based on soil testing is the Soil Health Card Scheme.