For someone who is just learning about soil, they may want to know what the difference is between soil fertility, soil productivity, soil health and soil quality.
In this guide, we provide a brief outline of what each is, and how differ from each other.
Summary – Difference Between Soil Fertility, Soil Productivity, Soil Health & Soil Quality
It’s worth noting that different sources might have slightly different definitions of these terms, and use them interchangeably.
We’ve provided more detailed descriptions of each of these terms below.
But, a summary of each might be:
Soil fertility is how well the soil can deliver a certain level of production or yield, and is directly tied to the chemical, physical, and biological characteristics of the soil.
Some of those characteristics involve having adequate nutrients and water supply, the right physical soil structure, and beneficial living organisms in the soil.
You can also read more in this guide about how to improve soil fertility and overall soil quality.
Soil productivity is concerned with the end production of the soil.
Soil productivity for example could be expressed as the total tonnage of a crop that a square area of soil produces, or the tonnage of crop that is produced per square area.
Soil productivity might not have as much of a focus on the characteristics of the soil compared to what the soil can produce.
Some sources though use the terms soil fertility and soil productivity interchangeably.
Soil health goes beyond the fertility or the production of the soil.
Soil health is the condition that the soil is in for whatever use the soil is being used for, whatever functions it has to perform, or for whatever it is being assessed for.
The soil might be assessed from an agricultural perspective (and look at aspects of short term production, as well as long term sustainable production), but it could also be assessed from an environmental perspective (where agricultural production might not be as relevant as perform functions to serve an ecosystem).
The terms soil health and soil quality are used interchangeably by different sources.
Soil quality is very similar to soil health, and almost the same in a lot of ways.
It is the quality of the soil to serve whatever functions it needs to provide.
High quality soil serves it’s functions and uses at a high level, and low quality soil vice versa.
The quality of the soil (and it’s ability to serve whatever functions and uses it’s being assessed for), are usually tied to the the soil characteristics, how the soil is managed, and the environment around the soil.
As an example of assessing soil quality, this website has various tools and data for assessing the soil quality in each state across Australia
What Is Soil Fertility?
Soil fertility is the ability of soil to sustain a certain level of agricultural production or plant growth (as well as yield), by having favorable chemical, physical, and biological characteristics
Physical characteristics can include things such as soil texture, structure, porosity, soil density, drainage and surface hydrology
Chemical characteristics can include things such as the nutrient status, and pH level
And biological characteristics can include things such as the beneficial living organisms in the soi (like mycorrhizae, other fungi, bacteria and worms)
Soil fertility mainly involves the soil a) having the right supply of nutrients (macro and micro) and water, and b) also having the absence of harmful substances or chemicals that could inhibit production or growth
But, there are also a range of other factors that can determine the fertility of soil as well
So, with soil fertility, the soil itself, and what’s in the soil are important to assess
What Is Soil Productivity?
Soil productivity, as the name suggests, refers to the ability of the soil to produce whatever is being grown in it.
Specifically, it’s the ability of the soil to produce a certain level of agricultural yield, or support a certain plant or crop growth to a defined rate, level or amount.
As an example, the more total agricultural product that soil on a plot of land can produce per square area, the more productive that soil is.
Productive soil might also refer to the speed of growth, or any other metric of production.
Soil productivity is very similar to soil fertility, and many sources describe them as being the same thing (which makes sense)
Fertile soil is usually productive, and productive soil is also usually fertile.
But, soil fertility might be more concerned with the chemical, physical, and biological properties and characteristics of the soil. And, these characteristics obviously lead to an outcome (which is the level of productivity).
Soil productivity might be less concerned with looking at the properties of the soil (although the properties of the soil are obviously essential to the soil being productive), and more concerned with looking at the end measure of production that the soil produces e.g. what is it’s yield per square area, or what is it’s total yield in terms of weight of product produced?
Soil health goes beyond the fertility of the soil.
Soil health is the condition that the soil is in for whatever use the soil is being used for, whatever functions it has to provide, or for whatever it is being assessed for.
Soil health from an environmental perspective is the ability of the soil to meet it’s functions within an ecosystem and serve the environment i.e. it’s functions to support living organisms and maintain biological diversity, hold and filter water, store carbon, and for nutrient cycling. Importantly, some of these functions like the ability to filter water and contribute to water quality, and store carbon, also help humans and human health.
From an agricultural perspective, soil health might encompass soil fertility, soil productivity, and also soil sustainability for farmers that are wanting to preserve their soil. It’s more focussed on agricultural production than environmental health.
So, it’s possible soil can be healthy from an environmental perspective, but not an agricultural perspective, and vice versa. It depends who is assessing it, and what for.
Soil health takes into consideration physical factors like soil structure, and also biological activity.
But, it also takes into consideration environmental issues like land and soil degradation (like erosion and other forms of degradation) that can impact a soil’s ability to perform it’s functions.
rethink.earth has this description of soil health:
Soil health … ‘derives from a strong interaction between the physical, chemical, and biological components of the soils’ … Geology, topography, climate, vegetation, human activity, and time, shape these factors … and, in turn, determine soil fertility, biodiversity, nutrient recycling, physical structure, carbon retention, and other ecological functions that make for soil health.
Soil quality is very similar, and essentially the same as soil health (they are often used to describe the same things).
Soil quality is a measure of quality of the soil, when assessing the functions it needs to provide in either an environment unmanaged by humans, or in a managed scenario where it is being used by humans for something such as farming.
In a natural unmanaged environment (unmanaged by humans), high quality soil might support living organisms, help regulate water, sequester carbon, cycle nutrients, and more.
When managed by humans on a farm, high quality soil might retain water, retain nutrients, be considered a fertile soil, and have a high level of productivity (just as a few examples)
Takes into consideration the ability of soil to support and sustain the needs of eco-systems and the environment, plants and animals, air and water quality, and human health.
A few other different descriptions of soil quality:
… Soil quality is the capacity of a specific kind of soil to function, within natural or managed ecosystem boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and support human health and habitation (wikipedia.org)
A healthy soil has biological, chemical and physical properties that promote the health of plants, animals and humans while also maintaining environmental quality. (soilquality.org.au)
You can find an example of a Soil Quality map at soilquality.org.au
The different factors that make up each soil quality indicator (biological, chemical and physical are listed and grouped with data)
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