‘Agriculture is the most Healthful, Useful and Noble employment of man’.

~ George Washington ~

Organic Fertiliser use & Phosphorus

Last time we decided that adding an organic component to any farming system would be beneficial to managing nitrogen.

This issue we will see if the same can be said of Phosphorus.


The diagram above gives us a hint as to the complexities of how phosphorus (P) behaves in soil.

With this in mind I thought I might break it up into the key points.

  •             Phosphorus is quite immobile in soil. Where you put it is where it stays. The only significant losses occur with crop removal, or if the soil itself washes away
  •            Organic Phosphorus is mineralised by the action of biology and so a healthy carbon source will be beneficial..
  •            The three “Lock up” mechanisms can work quite quickly. This has consequences when large amounts of soluble Phosphorus from mineral fertilisers is applied at once. Studies have shown as much as 85% of applied Phosphorus can be locked up.
  •            While not shown in this diagram pH is a crucial factor in Phosphorus efficiency. pH below 6 will quickly result in iron and aluminium binding your Phosphorus and locking it away, and with a pH above 7.5 calcium will do the same.


So where does all this leave us?


Job number 1 is get your pH sorted out, doing this will resolve 2 of the 3 lock up pathways.

However even with that done, we know that Phosphorus will not stay in a soluble form for very long anyway, so the idea of “Loading the soil up with Super Phosphate” and then forgetting about it probably won`t deliver very good value.

We could decide to wear our tractors out by applying it in small quantities more regularly. Or we can just use an organic version that will mineralise slowly, supplying the plant just what it needs, and feeding the soil biology as is goes.


With all that said, I guess that organics can play a part in the management of phosphorus.


Ross Cotton, Hervey Bay QLD

Ross Cotton lives in the coastal township of Hervey Bay, Queensland. Ross’s Herb & Vegetable garden has grown into a highly productive food production.

‘People ask me how do you keep your garden looking so healthy?
The answer is quite simple. STOP using second-rate products!’

Like most gardeners I’ve used the cheap potting mixes and slow release fertilisers resulting in slow growth plants that fall pray to Bugs and aphids. Then not so long ago while attending a festival I came home with a bag of Katek Organic Super Growth.

I could not believe the results the growth and colour of my plants was incredible to the point that I had more than I could use! I now supply a group of healthy eaters that purchase weekly Organic and Chemical free produce for their families.

To keep my supply running smoothly, I have a set regime when planting as follows; I give the whole patch a light fork over, and a dusting of Katek Organic Super Booster, then I add a layer of my compost, that I compost on site. I then follow that by a layer of Katek Superior Potting Mix.  If I am planting seed I cover the seed with Katek Superior Potting Mix as well.

The results are amazing! We are now picking 15 plus bunches of herbs a week; such as Dill, Lemon Balm, Sage, Italian Parsley, Afro Parsley, Green & Garlic Chives, Rocket, Radish, Kale, Oregano and much more!

We grow a wide variety of everything and all from 15 square metres that I call the “Veggie Patch”. I have been so impressed with the results from Katek products, that I am about to double my garden size to meet demand and to keep my rotation to a point of continuous supply.

Put LIFE back in your soil!


Super Growth Liquid Fertilizer is formulated to improve soil health and boost plant and root growth. Feeding through both the roots and leaves means fast results.

Combined with our composted POULTRY MANURE, Super Growth Liquid contains:

LIQUID FISH – Full of naturally balanced minerals and trace elements.  Supports earthworms and micro organisms.

KELP – Important in protecting plants during hot, dry weather or during times of frost.  Builds pest and disease resistance.

HUMIC & FULVIC ACIDS – To improve the soil, increase plant root growth and metabolism and help plants deal with environmental stresses.

Super Growth Liquid is currently being trialled on a wide range of crops including corn, cane and horticulture.

For more information on commercial applications contact Andrew on 0427 223 307.

It is also great for the whole garden, including palms, shrubs and natives.

Available in 1L & 5L Bottles, 20L & 200L Drums & 1000L Pods.