A Soil Sample Case Study

Does your soil have enough of the appropriate minerals in the right balance to grow truly nutrient dense food? A soil sample will tell you.

Vegetables, fruits and grains are a major source of vital nutrients, but generations of intensive agriculture have depleted our soils to historic lows.

As a result, a soil sample would tell you that the broccoli you eat today may have less than half the vitamins and minerals it would have had less than a century ago.

We can grow our own vegetables using lots of compost and avoiding chemicals, but how do we really know our soil has enough of the appropriate minerals in the right balance to grow truly nutrient dense food?

In Issue 14 of Pip, we explore the idea of adding minerals to your soil to ensure it has the full range of nutrients required to grow nutrient dense food. This is on top of adding compost and other organic materials.

Below is a chart of nutrients, what they do, what a deficiency looks like and how to add them to the soil.

To really be sure what nutrients are lacking in your soil, a soil sample test is needed, which we delve deeply into in Issue 14.

Nutrient Table


What is does

What a deficiency looks like

Form it comes in

CalciumImportant part of the plant’s cell wallBrowning of leaf tips

Bulb and fruit grow abnormally

Stunted growth

Limestone (calcium carbonate)

Agricultural (Ag) lime

Dolomitic lime (contains some magnesium)

Gypsum (calcium sulfate)

Oyster shell lime (calcium carbonate)

MagnesiumBuilding block of chlorophyll, vital to photosynthesisYellowing of leaves between leaf veinsDolomite

Magnesium oxide

PotassiumProtein synthesis, buffers plants against the effects of droughtBrowning of leaf tips

Reduced plant growth

Potassium sulfate
SodiumAid metabolism and synthesis of chlorophyll in plantsExcess more common (looks like wilting and stunted growth)Sea salt
PhosphorusPart of plant cells, essential for plant development and plant energyDiscoloration of leaves and stunted growthHard rock phosphate

Soft rock phosphate

Bone meal


SulfurEssential for protein synthesis and chlorophyll productionYellowing of leaves between leaf veins, affecting youngest upper leaves firstYellow sulfur
BoronTransport of sugars in plants, cell division, seed developmentStunted, distorted growth, particularly on the growing tipLaundry borax
NitrogenVital for photosynthesisYellowing of leaves between leaf veins, affecting lower older leavesGreen manure crops

Seedmeal, feathermeal, fishmeal

Composted animal manures

Minors: Iron, Zinc, Manganese, CopperPromote growth, photosynthesis, cell wall, plant hormonesLeaf curling and death, yellowing of leaves between leaf veins, stunted growth.Zinc sulfate, manganese sulfate, copper sulfate
Traces such as cobalt, selenium, molybdenumPromote growth, essential in small amounts, uses are variedMottled leaves, white stripes on leaves, yellowing leaves, stunted growthLiquid or granualised kelp or azomite

Soil Sample at Pip Headquarters

We took a soil sample from all our vegie beds at Pip Headquarters and sent them away to be sampled. They came back showing high levels of nitrogen, phosphorus, chloride, magnesium and potassium. Apparently this is typical of a soil where too much manure and compost have been applied.

We are working with a soil specialist to talk about what we need to do to bring the soil back into line. Stay tuned!

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