Calphos Soft Rock Phosphate - Regular Powder (50 lb)

Calphos Soft Rock Phosphate – Regular Powder (50 lb) is a premium-grade soft rock phosphate and natural phosphate fertilizer ideal for enriching acid soil and slightly acidic environments. This finely milled rock phosphate powder is a rich source of calcium phosphate that gradually releases phosphorus, supporting healthy root systems, improving soil fertility, and promoting strong plant growth over the long term.

Key Benefits & Features

• Balanced Nutrients: Contains 20% P₂O₅ (with 3% immediately releasing phosphorus) and 18% calcium—ideal for optimal growth and maintaining proper soil pH.
• Slow-Release Formula: This phosphate fertilizer gradually releases nutrients and trace minerals, making it highly effective for improving soil structure and nutrient retention.
• Supports Healthy Soil Ecology: Boosts microbial activity and soil structure when used with organic matter, enhancing plant vitality and resilience.
• Minimizes Leaching: Nutrients stay in the root zone, reducing environmental runoff and making it a smart choice for sustainable farming.
• Long-Term Effectiveness: Provides a steady supply of phosphorus for up to 5 years, reducing the need for frequent reapplication.

Application Guidelines

• Soil Test First: Always perform a soil test to determine appropriate application rates for your crop and soil condition.
• Field Use: Apply approximately 1 ton per acre on acid soil or phosphorus-deficient ground.
• Tree & Orchard Use: Apply 1–10 lbs of Calphos powder per planting hole and mix thoroughly with surrounding soil.
• Pre-Planting or Blending: Incorporate into the soil before planting or blend with compost and other organic matter for a balanced soil amendment.

Why Choose Calphos?

• OMRI-listed for organic production
• Derived from ancient marine deposits for reliable nutrient quality
• Combines calcium phosphate and soft rock minerals to nourish slightly acidic soils
• Delivers long-term, slow-release performance for sustained results
• Excellent choice for row crops, orchards, and soil-building programs focused on enhancing soil naturally

For smaller applications, Calphos Soft Rock Phosphate is also available in a 5 lb bag.

Explore more options in our High Phosphorus Fertilizer Collection or shop the full range in Fertilizer & Growing Supplies.