SKU: 22967337996
calcium phosphate fertilizer for plants

calcium phosphate fertilizer for plants Calphos

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Description

calcium phosphate fertilizer for plants CalphosCalphos Soft Rock Phosphate is a natural phosphate fertilizer made from finely ground soft rock. It is OMRI listed for organic use and is especially effective in acid soil and slightly acidic environments. This product is a reliable source of calcium phosphate and trace minerals that gradually release into the soil. The slow release of nutrients supports healthy plant growth, improves soil fertility, and provides benefits that last for the long term.

Calphos Soft Rock Phosphate is a natural phosphate fertilizer made from finely ground soft rock. It is OMRI-listed for organic use and is especially effective in acid soil and slightly acidic environments. This product is a reliable source of calcium phosphate and trace minerals that gradually release into the soil. The slow release of nutrients supports healthy plant growth, improves soil fertility, and provides benefits that last for the long term.

Why Use Calphos Soft Rock Phosphate?

Unlike many synthetic phosphate fertilizers, Calphos is a natural phosphate source that feeds plants steadily over time. Because it gradually releases phosphorus, it does not wash away easily with rain. Instead, it stays in the root zone, helping plants build strong root systems and maintain healthy soil structure. This makes it an excellent choice for growers focused on enhancing soil naturally while reducing the need for frequent reapplication.

Calphos contains about 20% P₂O₅, with 3% immediately releasing phosphorus for quick results and the rest breaking down slowly for long term benefits. It also provides around 18% calcium, which helps maintain proper soil pH and supports optimal growth.

Key Benefits of Calphos Soft Rock Phosphate

  • Balanced Nutrition: Supplies phosphorus and calcium phosphate in a form that plants can use steadily.
  • Slow Release Performance: A true slow release fertilizer that feeds plants for up to 5 years.
  • Supports Healthy Soil Ecology: Works well when mixed with organic matter, encouraging microbial activity and improving soil structure.
  • Minimizes Nutrient Loss: Reduces leaching and keeps nutrients available in the root zone.
  • Versatile Applications: Useful for row crops, orchards, trees, and general soil-building programs.

Application Guidelines

For best results, always start with a soil test to understand the nutrient needs and recommended application rates for your soil type and crops.

  • Field Use: Spread about 1 ton per acre on phosphorus-deficient or acid soil.
  • Tree & Orchard Use: Apply 1–10 lbs of Calphos in each planting hole, mixing it well with the surrounding soil.
  • Pre-Planting or Blending: Incorporate into the soil before planting or blend with compost and organic matter for a balanced amendment.

Because Calphos gradually releases nutrients, it provides both immediate and lasting results, reducing the need for repeated fertilizer use.

A Sustainable Choice for Plant Growth

Calphos Soft Rock Phosphate is derived from ancient marine deposits, giving it a natural balance of phosphorus, calcium, and trace minerals. By combining these nutrients, it helps create fertile soils that support healthy root systems, vigorous crops, and healthy plant growth.

Its natural composition makes it one of the most reliable phosphate fertilizers for gardeners and farmers who want to focus on enhancing soil rather than relying on quick fixes.

Why Gardeners and Farmers Choose Calphos

  • OMRI-listed for organic production.
  • Reliable, natural source of phosphorus and calcium phosphate.
  • Excellent for slightly acidic soils and acid soil.
  • Improves fertility while supporting healthy microbial life.
  • Provides both quick and long term nutrient availability.
  • Ideal for row crops, fruit trees, and soil-enrichment programs.

Available Sizes

This 50 lb bag is perfect for larger gardens, farms, and orchards. For smaller applications, Calphos Soft Rock Phosphate is also available in a convenient 5 lb bag.

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.

Shipping Notes
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  • Delivery to the USA:
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Exchange/Return Notes
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  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
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SKU: 22967337996

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Amber Danielle Farmer-Sutherland
Fort Morgan, US
★★★★★ 5
Perfect!
Size: 24inch, Color: Walnut, Size: 24inch, Color: Walnut
Perfect! Just what I wanted. Sturdy, came with all the pieces, and very pretty wood.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on November 20, 2025
K
Verified Purchase
KB
Boise, US
★★★★★ 3
They worked for replacing shelves but I wouldn’t mount them on my wall
Size: 24inch, Color: Walnut
I specifically bought these shelves because of their dimensions. I have a built-in cabinet and when we moved in 6 or so years ago, the previous owners must have taken them with them when they moved. It’s been bothering me the whole time I’ve lived here and wanted to make some but just never found the time to get around to it. I measured them out and these floating shelves were perfect for the dimensions I needed to replace the missing shelves. Would I put these on my wall(s)? Absolutely not unless I corrected the mounting issues. One thing that really stuck out to me was how bad the design was for mounting these shelves. When I took them out of the packaging, the brackets were falling out of the back everywhere. This did not inspire too much confidence that if I hung them up, they would be stable. I’ve had a ton of floating shelves similar to this mounting design, but the arms that the boards slide into on the wall for this particular shelving are thin and flat (while being easily mailable with your hand alone) in comparison to every other one I’ve had being round, or at least decently thick, sometimes with additional screws that you can insert under the board and into the mounting arms for extra stability. Also, any time I’ve ever had to mount a similar floating shelf, it took some finesse and strength to release the mounting arms from the back of the shelf because they fit very snugly. The fact that the mounting brackets were falling out of the back means that they are not snug and prone to be very loose. Another thing that stuck out to me is that the shelves are hollow. Now, for my purposes, this is fine, but again, detracts significantly from the confidence that these would be stable if mounted on the wall and would most likely droop when weight was applied. I also took issue with the fact the boards had no protective covering and were jammed into a box, with the hardware pressing against one of the boards tightly. I just flipped the shelf over to mask the defect from packaging but the side I wanted to use because it had better coloring was the damaged side. Mine did not come with any mounting directions but some common sense would be all you needed to put up something so simple. However, it did not come with a template to mark the wall for spacing, which adds to the difficulty because you have to have precise DIY measurements to slide the boards onto the mounting arms correctly. To be honest, if I were to mount these, I would bypass the shoddy mounting provided and go with some heavy, durable brackets underneath. Overall, these shelves worked for my purposes but I can see how the reviews would be very mixed in terms of mounting and quality. I did get these on a limited time deal and they were priced at approximately $8 per shelf, which was a really good deal to get 4 shelves for that price in comparison to the “normal” price resulting in approximately $11/shelf. I wouldn’t have paid full price for these and would have been highly disappointed had I with the intention to mount them, especially since I would have needed to provide better and more stable mounting hardware. They are lesser quality than others within the same price range and I think you could do much better if your intention is to mount them.
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Reviewed in the United States on January 11, 2025
A
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Amazon Customer
Draper, US
★★★★★ 5
Would purchase again
Size: 48inch, Color: Light Walnut
I was not sure what to expect when I purchased these. I thought maybe they were going to be a fake particle board. But this was a solid wood. Easy to install, no directions were in the box. There was a few chips in the corner of the wood but overall I would purchase again.
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Reviewed in the United States on January 20, 2026
A
Verified Purchase
Amazon Customer
Birmingham, US
★★★★★ 5
Love these and will be getting more. Very pretty.
Color: Oak, Size: 39.4"L x 8"D, Set of 2, Color: Oak, Size: 39.4"L x 8"D, Set of 2
Very nice shelves they look great up and were easy to install. Same color shown in picture. They seem very sturdy on the wall and I love the look of them. They are light weight and a good size just a little plunder 40 inches. Good quality for the price. I'll be buying again.
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Reviewed in the United States on March 25, 2026
M
Verified Purchase
Myers3
Los Angeles, US
★★★★★ 5
PERFECT!
Color: Walnut, Size: 23.6"L x 8"D, Set of 2, Color: Walnut, Size: 23.6"L x 8"D, Set of 2
Just as good as expected! Great quality, no issues. Easy to construct and look amazing!
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Reviewed in the United States on May 15, 2026

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