Did you know that as little as 10% of phosphate you apply with SSP is available to plants at any given time? The problem with most soils is often not a lack of phosphate, but a lack of available phosphate. That’s why at The Growing Group we have concentrated on increasing the plant-available phosphate in your soil. The result is CarboPhos, a phosphate fertiliser that is applied at half the rate of SSP, and doesn’t need subsequent lime as a result of its application.

Click here to download our CarboPhos flyer.

Comparing CarboPhos to SSP

Traditional fertilisers are typically 75-85% water soluble, resulting in leaching, nutrient loss, and pollution. Our very low-leaching product provides all the benefits of phosphate fertiliser in a low soluble form – less than 20%. Formed into 2-5mmm granules for easy application, it aims to provide a replacement for traditional phosphate products such as superphoshate and DAP. This product boosts soil and root performance, overcomes pollution from leaching, improves nutrient retention, and balances soil acidity – requiring no subsequent lime application.

Improve your soil biology

Did you know that a plant can only draw phosphate from about 26mm away from its roots? So to improve phosphate uptake in the plant you can do two things: increase the ability of a plant’s roots to grow; or build up soil biology that can move the phosphate to the plant’s roots. Traditional fertilisers that harm soil biology decrease the availability of phosphate, as well as many other elements that are essential for plant growth. CarboPhos has high organic carbon content, fuel for the beneficial biology in your soil.

Finely ground raw materials

By grinding our raw materials extremely finely we have increased the surface area available for the soil biology to break down the elements within CarboPhos. The finely ground phosphate is then chemically reacted within the soil, making it available to the plants. The benefits of finely ground phosphate have been known for a long time, however the application of ground powder makes it extremely difficult to handle (on a windy day most of it ends up on your neighbour’s farm!). So we have reformed these powders into 2-4 mm granules which can be applied just like you would any other granular fertiliser.

What are the benefits?

CarboPhos assists with a number of functions that improve phosphate availability, whereas SSP inhibits most of them. Farmers already take simple measures to make phosphate more available through the application of lime. This increases the soil pH, which is just one (very simple) way of increasing phosphate availability. Below are just a few more of the complex interactions that CarboPhos promotes to improve your soil:

CarboPhos contains organic Carbon from coffee bean residue, seaweed, sugar. All of these are beneficial to the soil biology, which in turn is critical for soil availability. For example, mycorrhizae are soil fungi that form a symbiotic association with plant roots. They connect with plant roots and extend into the soil, acting like extensions of the plants root system by absorbing nutrients and transporting them back to the plant roots. In exchange, the mycorrhizae receive sugars manufactured by the plant. In some cases this can increase phosphate uptake by 50%.

Nutrients are more available when they are finely ground. The more finely ground, the greater the total surface area. Fertiliser needs to be broken down (by weathering or biology) before it can be reacted with other chemicals to form available nutrients. Increasing the surface area reduces the amount of time required to make this beneficial reaction occur.

Soil acidity affect many functions within soil. With regards to phosphate, when soil pH is less than 6 Aluminium becomes strongly positively charged. If it becomes even more acidic (less than 5), there is a similar effect with Iron. Conversely if a soil’s pH is greater than 7 (alkaline), the positive charge of Calcium increases. In any of these instances, phosphorus will bind to these elements, and becomes largely unavailable. Once it is fixed, Phosphate can remain in the soil for decades. This is the reason why farmers apply lime – to release the phosphate that is bound to Iron and Aluminium. CarboPhos has the equivalent pH of fertile soil, so it doesn’t need lime applied afterwards.

CarboPhos includes an extensive list of trace elements that farmers miss out on when they apply SSP. These include: Calcium, Silicon, Iron, Molybdenum, Carbohydrates, Selenium, Zinc, Humates, Sulphur & Boron

Lower application rates result in lower applied costs & transport costs for the farmer. Environmentally, this means that Phosphate (an irreplaceable resource that it expected to run out by the end of the century) is being used more efficiently than with SSP.

CarboPhos is much less water soluble than SSP, giving a more consistent dosage of phosphorus to your soil, which is available for longer

Want to know more?

As you probably know from your farming experience, SSP has the disadvantage of diminishing returns – each year more is required to provide the same results. This may be fairly common knowledge for farmers, but it came as a bit of a shock to Chris when he purchased the farm in Kekerengu (especially since he had been trading traditional fertilisers for 25 years). So after 10 years of research, a lot of questions, and collaboration with scientists we managed to get a phosphate product that is directly substitutable for SSP, without the problems of diminishing returns (which may not be the best business model, but we are certain it is good for repeat business!).

The generation 1 product was developed and trialled in Europe & New Zealand in 2008 with seemingly good results.

We believed we could do better and worked to develop a new formulation and address aspects of the earlier work we believed were missing. Results have shown we were correct  and the product we ow market is the result of that work. We have been granted a patent for our product, branded CarboPhos. This has been extensively trialled in New Zealand, and shows an even better performance.

The focus of SSP is to increase the amount of phosphate in the soil. The focus of CarboPhos is to increase the nutrients avaliable to the plant. To do this you need to work with the soil’s natural ability to deliver nutrients to a plant. Instead of just increasing the phosphate quantity in the soil, it is important to ask – how can I make the phosphate more available? The answer isn’t just more phosphate! There are endless interactions being performed within the soil, mostly by soil biology.

Phosphate must be in one of two forms to be plant available: Primary orthophosphate anion & Secondary orthophosphate anion. All Phosphorus sources applied to the soil must be converted to the orthophosphate forms before a plant can utilize them. However, applying these forms of Phosphorus to the soil does not guarantee that they will remain in that form for very long. Because phosphorous is highly reactive, it is readily converted to other, less soluble forms. The particular forms that are created depend on other soil factors such as the soil pH, temperature, moisture, other elements, and others.

In most situations there is very little soluble Phosphorus in the soil at any point in time. It has been estimated that at any point in time, the solution/available forms of Phosphorus in many soils may only amount to from 0.01 to 0.06 ppm (10-50 grams P/acre). This Phosphorus will typically move no more than about 2.5 mm in the soil. Roots quickly deplete the 2.5 mm cylinder of soil around each root and must continually grow into new areas of the soil to maintain adequate Phosphorus intake.

The soil is the key here – the more fertile the soil, the more efficient it is. Fertility is not just measure of phosphate quantity, it is a measure of organic matter, biology, pH, temperature, moisture etc.





  • contact us

    25 McPherson St
    Richmond 7020
    New Zealand

  • follow us

  • sign up for our mailing list.