But, this guide specifically addresses improving your soil’s fertility, quality, health, drainage and structure.
*These are general principles that can help with improving soil. Actual and specific soil improvement plans will differ on each plot of land and in each region in the world
What Are The Differences Between Soil Fertility, Health & Quality?
Read more in this guide:
Where To Read More About Soil Fertility
In regards to soil fertility specifically, you can read more about that in this guide:
What About Soil Drainage & Soil Structure?
These two are interrelated.
Soil structure is how the soil particles arrange or clump together to form pores, spaces and gaps in the soil as a whole. Soils like clay tend to clump together very tightly because of the small soil particle size, and soils like sand tend to be far more loose and have less structure due to the large particle size.
Good soils needs space for both water and air to move between the soil particles, but should also be able to retain some water and nutrients for the plant roots to absorb, and not allow them to completely wash away. Soils with good drainage can do this.
How To Improve Soil Fertility
The factors that impact soil fertility, and the ways to improve those aspects of soil fertility might be:
- Nutrients (Macro, & Micro Nutrients)
Two of the easiest ways to get nutrients into the soil are through the break down of organic matter (mulch, compost, manure), and the addition of fertilizers (synthetic fertilizers, or organic manures).
- pH of the Soil
You can test soil pH with a simple soil pH testing kit. Once you know soil pH, you can either pick plant life that grows in that natural pH range, or you can apply soil amendments to change the soil pH to a pH range of the plant life you want to grow.
- Parent Rock/Soil Material
This is out of your control unless you pick a plot of land (prior to growing or setting up a gardening patch) that has parent material that helps produce the type of natural soil that you want.
- Clay Content, & Cation Exchange Capacity
CEC is the soil’s ability to hold onto nutrients.
Soils with a certain level of clay content tend to hold onto nutrients better. Overall, CEC is determined by clay %, the type of clay, soil pH and amount of organic matter.
So, make sure these factors are in the right balance so the soil can hold onto nutrients.
If we look at loam type soil for example, which is seen as a fertile soil for growing many types of vegetables and plants. a good loam composition might consist of 40 percent sand, 40 percent silt, and 20 percent clay.
- Bulk Density
Soil that is too compact is not fertile for a number of reasons, with poor water drainage and aeration being just two reasons.
Extreme clay soils and heavy soils tend to have a high level of bulk density, so, it’s important to have a soil that strikes that balance between having decent soil structure that clumps together well enough, but is also loose enough to allow air and water to pass through it.
- Moisture & Water Content
Soil needs regular watering to ensure the moisture and water content of the soil is at the right leve.
- Soil Structure
See below under the ‘how to improve soil structure’ section
- Presence of Micro-Organisms & Beneficial Bacteria/Fungi In The Soil
You can add fungal spores and beneficial fungi like Mycorrhizal fungi to soil, but, if you regularly add organic matter to soil and keep the soil healthy, you’ll create a natural environment for micro organisms like fungi, bacteria, worms etc. to thrive in the soil and break down organic matter for nutrients in the soil.
- Nutrient Release Capability Of Soil
Assuming the soil has a good supply of nutrients, having a well balanced soil texture (soil type), and the right amount of air and water in the soil impacts the release capability of the soil.
- How Well Soil Retains, & Drains Water & Air
Discussed in other sections of this guide
- Presence Of Groundwater
If there is groundwater close to the level of the soil you are growing in, make sure the groundwater isn’t saline – or it can cause salinity problems in your soil
- Usable/Exploitable Depth Of Soil
The depth of the soil you are growing in has to be deep enough for the plant life you are growing to establish it’s roots properly in. So, it helps to know the depth the roots grow to, and make sure you have enough soil depth to accomodate.
An external factor that can impact soil fertility. For example, heat makes clay soils dry up and go solid or crack, and wet conditions can lead to wet clay soil that goes sticky and compact.
Sloping land vs flat land.
Sloping land can cause soil degradation issues as one example, especially with wind and water erosion.
How To Improve Soil Health
Soil health goes beyond soil fertility.
It considers some of the following factors:
- Soil Structure
Discussed in the ‘how to improve soil structure’ section below
- Biological Activity In The Soil
How well micro-organisms, beneficial bacteria and fungi, and other lifeforms like worms can thrive. Organic matter to break down, well aerated soil, and soil that retains and drains water contributes to biological activity in the soil.
Also, limiting synthetic or harmful chemicals like pesticides and herbicides can help preserve beneficial bacteria populations over time.
- Preventing Soil Health Issues Like Soil Erosion, Acidification, Salinity etc.
Soil erosion can be minimised by protecting the soil from water and wind damage (cover crops, using flat soil, good soil drainage can all help with this).
Soil acidification can be minimised by controlling the amount of nutrients you add to the soil – mainly nitrogen based fertilizers. Acidification happens when there is an excess of hydrogen cations added to the soil, which lowers the pH.
Soil salinity mainly occurs due to saline groundwater reaching a high level just below the soil level.
How To Improve Soil Quality
Soil quality takes into consideration the needs and health of humans, animals, plants and the environment when using the soil.
Good soil fertility benefits humans because productivity will be high.
Healthy soil benefits micro-organisms and plants because they have an environment in which they can thrive.
Looking at the use of sustainable and organic growing practices (limiting synthetic pesticides, herbicides and fertilizers, along with other practices like reduced tillage) can benefit the environment in the long term by limiting land degradation and other forms of environmental pollution. The leaching away from the soil of fertilizers and pesticides can lead to water pollution at other source points for example. Nitrogen based fertilizers can also lead to long term problems with air pollution as another example.
How To Improve Soil Drainage
Good soil structure contributes heavily to good soil drainage.
Heavy soils and clay soils can have poor soil drainage due to their structure. Some people have had success adding sand (and sometimes silty soil) to clay soil to loosen it up.
But, for others like those at provident-living-today.com, they’ve found adding sandy soil to clay can in fact harden it up. They found that adding organic matter consistently over an extended period of time worked better.
Some soils may be unworkable, or may only be workable for experienced gardeners and growers. In this case, raised garden beds with imported soil, or growing plants suited for the soil you have may be the best options rather than trying to amend the soil too much (and risking wasting your time and money).
How To Improve Soil Structure
As discussed above, soil structure can be improved by firstly identifying the type and texture of soil you have.
Once you know that, you can work on adding other types of soil to the mix, and adding and mixing in organic matter.
Planting cover crops, minimising tillage and disturbance to the soil, and adding a thin mulch layer to the soil can also improve soil structure to differing extents.