RPR

For pricing please contact your DD Area Manager

Reactive Phosphate Rock (RPR) is a non-water soluble (slow release) natural phosphate source that can be applied directly to crops and pasture. RPR is best suited to soils with both low and high phosphate retention characteristics as it will reduce the amount of phosphate that is both leached and locked up in the soil. The result is an improved phosphate utilisation and plant production.

Categories Autumn, Calcium, Lime, Phosphate, Solid, Spring, Summer, Winter

NitrogenN: 0

PhosphateP: 13%

PotassiumK: 0

SulphurS: 0

CalciumCa: 35%

MagnesiumMg: 0

Why Use RPR?

RPR should be considered as a phosphate source in situations when:

Soils have a low pH (pH<6)

A soil at a lower pH will speed up the break down of RPR, while the RPR will also help improve the soil pH.

Soils have a low Anion Storage Capacity (ASC) (ASC<40)

Low ASC soils have low levels of phosphate binding sites therefore a limited ability to hold onto phosphate ions. Non water-soluble phosphate sources such as RPR on these soil types slowly release phosphate reducing the leaching losses and improving phosphate utilisation.

Soils have a high ASC (ASC>60)

High ASC soils contain large amounts of iron and aluminium oxides, which adsorb phosphate ions reducing its availability to plant roots. Therefore these soils require more phosphate to overcome deficiency and benefit from the use of both water soluble and non water-soluble phosphate sources such as RPR to improve phosphate utilisation and plant production.

Soils require only maintenance applications of phosphate

RPR is an efficient alternative to water-soluble phosphate sources on soils that have good phosphate levels and only have maintenance requirements.

A larger phosphate application is being applied (<40 units of P), i.e. capital P application

In this instance Dickie Direct often recommend considering a blend of water-soluble (fast acting) and non water-soluble (controlled releasing/RPR) giving a balance between short and medium term production gains, improving phosphate utilisation and extending the response.

Product FAQs

When to Use

Summer, Autumn, Winter, Spring

Precautions

RPR should be used in conjunction with Triple Super or DAP when a more immediate release of phosphate is also required.
When transitioning from more conventional phosphate forms RPR should be used in conjunction with Triple Super or DAP until sufficient phosphate has started to be released from the RPR, this can be 1-2 years depending on the soil environment and climatic conditions.

Phosphorus's Role in Plants

The most important role of phosphorus is the storage and transfer of energy that is generated through photosynthesis along with the metabolism of carbohydrates.
Phosphorus is an essential compound of Adenosine Triphosphate (ADP), the energising component driving plant development.
Phosphorus deficiency has a huge impact on plant growth and reproduction, reducing the plant processes noted below.
Processes aided by phosphorus:
- Large root growth
- Early formation of plant shoots
- Improved stalk and stem strength in crops
- Improved fruit, vegetable, and grain quality
- Seed formation
- Resistance to moisture and colder temperatures

Calcium's Role in Plants

Calcium is vital for both plant and animal growth
An essential part of the plant cell wall and membranes, aiding in plant structure and stability
Earthworm activity is increased by the presence of calcium in the soil profile, therefore natural soil aeration is also increased
Boosts soil microorganism activity, improving soil structure
Calcium deficiency affects fruit crop quality and growth, and limits biological activity
Calcium and magnesium work in synergy to promote stable soil structure
Involved in the signalling of the availability of other nutrients (e.g. potassium), through its secondary messenger characteristics
Assists in protecting the plant from biotic stresses

Key Benefits of RPR

The slow release nature of RPR improves phosphate utilisation and extends the response to phosphate in between applications, especially on soils with both high and low ASC.
RPR has a high calcium content, having a neutralising effect on pH. It is also not acidifying the soil like other forms of phosphate fertilisers. Save money on a reduced requirement for liming when using RPR.
Enhances soil health and biology. Soil microbes which are a vital component of healthy soils are more active in basic soil conditions, the non-acidic nature of RPR protects this environment. Get your soils doing more of the work for you.

What Makes Our RPR the Best in the Market?

Contains a high P content compared to alternative RPR’s resulting in lower freight and application costs.
Citric solubility ranges from 36%-40% as a result of the product being ground to an average particle size of 74 Micron. Allowing the phosphate to be made available to the plant faster than other RPR fertilisers.
A faster release period of 2-3 years in typical conditions; a quicker/better return on your fertiliser investment.
Very low heavy metal content with cadmium testing at 1-2ppm.
Blend with Sulphur 90S (slow release) to to meet medium and long term sulphur requirements.
Blend with DAP and/or TSP to achieve a balance between fast and slow release phosphate.

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RPR