Colloidal Soft Rock Phosphate (ACO Organic calcium phosphate)

Colloidal Soft Rock Phosphate (ACO Organic calcium phosphate)

Colloidal Soft Rock Phosphate is a clay based calcium phosphate rock, a slow phosphorus and calcium source for living soil, compost and garden beds. It is not the same as hard rock phosphate: the colloidal clay form is finer and releases to soil life more readily.

At a glance

• Type: amendment (phosphorus and calcium)
• Organic input status: ACO registered farm input 456AI (NTS). See the details and dates.
• Analysis: 8 to 9% phosphorus (18 to 21% as P₂O₅), 19.3% calcium, 15 to 26% silicon
• Use for: slow phosphorus and calcium in soil mixes, compost and beds
• Rate: 130 g to 650 g per square metre, broadcast and incorporated
• Certification: ACO (Australian Certified Organic) input, as stated in the product name
• Pack: bulk 500 kg and 1000 kg by quote

What it is

Soft rock phosphate is a colloidal clay based calcium phosphate, supplied by Nutri-Tech Solutions. It is not to be confused with regular (hard) rock phosphate. It carries 8 to 9% phosphorus (18 to 21% as P₂O₅), 19.3% calcium, 15 to 26% silicon and a range of trace elements, and is part of our soil regeneration programme as a microbe friendly phosphorus source.

Bulk is available in 500 kg and 1000 kg quantities. Email store@seaclifforganics.nz for a quote.

What it does

• Phosphorus drives energy transfer in the plant (ATP), early root growth, flowering and seed set. A shortage shows as purple old leaves and slow, cold roots.
• Almost none of the phosphorus is water soluble. Root acids and soil microbes release it over seasons, so it feeds the soil rather than spiking one crop.
• Phosphate binds to soil within millimetres of where it lands, so losses by leaching are small. That also means it needs to be mixed into the root zone, not left on top.
• The calcium and silicon come along with the phosphorus: every amendment brings passengers.

Analysis

Typical analysis (Nutri-Tech Solutions), % by weight

• Nitrogen (N) 0.00%
• Phosphorus (P₂O₅) 20.62%
• Phosphorus (P, elemental) 9.00%
• Potassium (K₂O) 0.84%
• Potassium (K, elemental) 0.70%
• Sulphur (S) 0.15%
• Calcium (Ca) 19.30%
• Magnesium (Mg) 0.46%
• Sodium (Na) 0.00%
• Iron (Fe) 2.00%
• Silicon (Si) 15 to 26%
• Manganese (Mn) 1100 ppm
• Zinc (Zn) 260 ppm
• Copper (Cu) 130 ppm

How to use

• Compost: 650 g or 500 mL per cubic metre.
• Modified media and potting soil: 650 g to 3.5 kg, or 500 mL to 2.5 L, per cubic metre.
• Modified media and potting soil: 32.5 g to 175 g, or 25 mL to 135 mL, per 50 L.
• Soil grown crops, broadcast and incorporate: 130 g to 650 g per square metre (1300 to 6500 kg per hectare).

Learn more in fifteen seconds

• Phosphorus: what it does
• Phosphate stays where it lands
• Too much P turns mycorrhizae down

Handling and storage

• Wear a mask to avoid inhaling particles and open the bag in a well ventilated area.
• Wear gloves and eye protection, and wash hands after use.
• Once opened, keep sealed and dry.