The Nutrient Cycle Episode 4 in the Garden Soil Series

On todays episode we are going to talk about the nutrient cycle in your garden. Last time we spoke about the Nitrogen Cycle however this is only one of the essential elements for plant growth.

Plants require 18 elements to sustain growth. Carbon Dioxide from the atmosphere and water or H20 provide the bulk of the Carbon Oxygen and Hydrogen for energy production and major structural elements. The other 15 elements generally come from the matrix the plant is growing in.

The 15 elements traditionally come from the soil. These are the nutrients of the nutrient cycle. They can be broken down into two general categories: Macronutrients and Micronutrients.

Macro and micro refer to the quantities of which they are required by the plant for growth. They are not categorized by their necessity for the plant as they are all necessary for healthy growth.

Macronutrients required are things like Carbon, Hydrogen, Oxygen Potassium, Calcium, so on and so forth. They typically form most of the plants mass. The full list is on the screen now.

Micro nutrients are required in much smaller quantities and are things like Iron, Boron, Nickel ext… They typically originate from the parent material as the rock degrades over time.

Both macro and micro nutrients can come from other organic material.

The plant takes up what it needs from the soil incorporating most of it into the plant itself. When the plant dies it decays releasing the component materials back into the environment. This is essentially the nutrient cycle.

Although there are many process involved in the nutrient cycle it does not have to be complicated in your garden.

Compost is a great way to recycle and add more of the organic material and add the essential elements back to your soil. With a diverse feedstock of plant and other organic materials such as eggshells compost can contain the elemental raw materials you require for healthy plant development.

You can add compost a number of different ways to your garden. I choose to compost using traditional composting methods and adding the organic material as mulch on top of my garden soil.

Some of the elements need to be in a certain either organic form like Nitrogen or inorganic form such as Calcium, this is referred to as the bioavailable form. In most cases beneficial organisms are responsible for converting the decaying material to a bioavailable form.

In order to make sure the garden soil, compost or mulch has the beneficial organisms it needs to make the elements bioavailable you can do a number of simple things to help them out.

Actively aerated Compost teas and Steeped Compost extractions both provide plant available nutrients but the bacteria that are essential to a lot of decomposition processes. They also serve as food sources and nutrient stores for other organisms that consume them and release their waste which contains more bioavailable nutrients.

Worms are your best friend. They not only eat and help decay the organic material in your garden but they release bacteria and plant growth hormones into the soil.

You can add them to your garden using compost created by giving organic material to composting worms. This is called vermicomposting. You can then add the compost and worms directly to your garden.

Alternately you can simply provide a nice home the native earth worms in your area. If your using mulch and composting you probably have already given them a nice home !

Finally and simply planting cover crops of green manure that culture bacteria or help repel harmful ones not only helps with the bacterial communities but can fix nitrogen and provide more organic material for your compost.

Common garden problems that are not caused by disease can often be attributed to deficiencies in one or more of these elements.

In summary setting the stage using compost, mulch, compost tea and vermilculture set the stage for active beneficial organism communities in your garden soil and compost will help keep the nutrient cycle turning. A healthy nutrient cycle will result in healthy garden plants that produce more for you and are much more disease and stress resistant.

About Stephen

The Alberta Urban Garden Channel hopes to promote organic gardening that is simple, sustainable and does not have to cost a lot. We do this by investigating the Science behind gardening, methods, practices and products to make sure that you will have the best chance of successfully growing your own food at home.