Integrated Nutrient Management in Black Gram improving soil fertility and yield using bio-fertilizers and organic manure (Research on Crops, 2025).

Research on integrated nutrient management (INM) in Black Gram (Vigna mungo L.) for 2025 highlights a critical shift toward balancing soil health with high productivity. Recent studies, notably those published in Research on Crops (June 2025), emphasize that combining bio-fertilizers with reduced chemical doses and organic manures significantly outperforms conventional 100% synthetic fertilization.+1

📈 Key Research Findings (2025)

1. Optimal Treatment Combinations

A pivotal study published in Research on Crops (Vol. 26, Issue 2, June 2025) by Verma et al. identified a specific “Best-Practice” formula for Black Gram:

• The Mix: 50% RDF (Recommended Dose of Fertilizer) + Vermicompost (@ 1 t/ha) + Enriched FYM (@ 2 t/ha) + PGPR + PSB (seed treatment each @ 20 g/kg).
• Yield Results: This combination achieved a grain yield of 1,492.68 kg/ha, significantly higher than treatments relying solely on inorganic sources.
• Growth Attributes: The dual inoculation of PGPR (Plant Growth-Promoting Rhizobacteria) and PSB (Phosphate Solubilizing Bacteria) led to maximum plant height (approx. 51.93 cm) and dry matter accumulation.

2. Soil Fertility & Health Improvements

Beyond yield, the 2025 research underscores the “Self-Healing” nature of INM-treated soils:

• Physico-Chemical Shift: INM practices lowered soil pH and EC (Electrical Conductivity) while significantly increasing Organic Carbon levels.
• Nutrient Availability: The use of vermicompost and bio-fertilizers created a steady nutrient release, improving the availability of Nitrogen, Phosphorus, and Potassium in the rhizosphere.
• Microbial Density: INM led to a surge in microbial populations and enzymatic activity (e.g., dehydrogenase activity), which facilitates long-term soil sustainability.

3. Economic and Quality Parameters

• Nutrient Uptake: In studies from Rajasthan and Tamil Nadu (2025), INM treatments recorded the highest N, P, and K uptake in both seed and haulm.
• Profitability: The 75% RDF + FYM + PSB treatment was noted for the highest Benefit-Cost (B:C) ratio (up to 3.69:1 in some trials), making it a pragmatic choice for resource-constrained farmers.
• Protein Content: The integration of Zinc (Zn) and Molybdenum (Mo) with organic manure was shown to enhance protein assimilation in the grains.

🔬 Summary of Bio-Fertilizer Roles

Conclusion: The 2025 research consensus confirms that 50–75% RDF supplemented with organic manures and bio-fertilizers is the superior strategy. It reduces environmental pollution from chemical runoff while ensuring the soil remains productive for succeeding crops (like mustard or lentils).