Soil Nutrients: What You Need to Know to Improve Plant Health & Productivity

When it comes to online gardening tips, a certain amount of skepticism is healthy. For example, according to one popular gardening site, when soil nutrients become depleted, “that’s where fertilizer comes in.”

The site doesn’t provide any additional information or advice so the next logical question is, “What is fertilizer, anyway?”

Fertilizer is any substance used to increase the productivity of the soil.  Technically speaking, fertilizer can be 100% all-natural…like cow manure, for example.

Still, most people associate fertilizer with packaged commercial products—many of which contain synthetic chemicals. Moreover, to qualify as a commercial fertilizer, many products only need to have nitrogen, potassium and phosphorus (N-P-K) as their primary ingredients.

Fertilizer’s Quick Rush

Synthetic fertilizers are designed to give plants a quick rush of food, not unlike the “sugar rush” we get when we ingest a plate full of carbohydrates. They work fast, but they are just temporary fixes. Chemical fertilizers don’t do anything to rebalance the health of the soil—and they ultimately lead to its further degradation.

Synthetic fertilizers also don’t typically contain a balanced amount of secondary macronutrients and micronutrients like those that are found in naturally fertile soil and which are essential for healthy plant growth. Once these essential nutrients become depleted from heavy usage or from natural weathering, they are not easily replaced (and most certainly not through synthetic means).

The Importance of Secondary Nutrients

So what are some of the secondary macro- and micronutrients that are essential to healthy plant growth? They are:

  • Silicon (Si) – a key component of plant cell walls; improves plant structure and increases resistance to pest and disease
  • Calcium (Ca) and Magnesium (Mg) – regulate soil cation exchange capacity that determines the availability of many other nutrients in the soil
  • Iron (Fe) – a catalyst to chlorophyll formation; many synthetic iron fertilizers are ineffective because the iron converts rapidly to forms that are unavailable to plants
  • Magnesium (Mg) – the central atom in chlorophyll
  • Manganese (Mn) – necessary for photosynthesis, nitrogen metabolism, and synthesis of enzymes
  • Copper (Cu) – promotes seed production and formation; plays an essential role in chlorophyll formation.

These essential nutrients, and many others, are made readily available to plants growing in soil that has been remineralized with all-natural volcanic basalt. Basalt is an igneous rock that, when crushed into a fine powder and applied to the soil, mimics the earth’s own slow manner of regenerating the soil through geological activities such as volcanoes and glaciers. It is Mother Nature’s own way of making minerals available to plants in the balanced form they need to develop stronger roots systems; build resistance to pests and disease; and deliver higher yields.

The next time a gardening site recommends “fertilizers” to replace depleted nutrients, stop and consider what your soil really needs. Then head to the nearest natural gardening center and buy a bag of all-natural volcanic rock dust.


When looking for a soil amendment made of volcanic basalt, look for a high-quality product that is listed by the Organic Materials Review Institute (OMRI) for use in organic production. One product that meets this criteria is Cascade Minerals Remineralizing Soil Booster which is made entirely in the USA from all-natural volcanic basalt from Central Oregon.