5 tips for trialling biological inputs

Jun 23

By Kim Deans

Experimentation to see how things work in our unique context is essential when we are restoring soil health. When we decide to trial any type of soil amendment in our context it is important to take a whole systems approach rather than a traditional, linear, input focused approach. This is particularly important when it comes to biological soil amendments.

It is easy to fall into the trap of applying biological amendments as a stand-alone add on to the system, sometimes side by side either with conventional or other biological inputs to “see if it works.” This approach has us watching the input in isolation to see what happens, looking for a short term, easily measurable visual response above the ground that we can connect to the input itself. When we take this linear, mechanistic approach, we are effectively trying to solve the problems with the same thinking that created them. The first step in trying biological inputs comes down to regenerating our mindset and taking a wholistic view of the soil ecosystem we are wanting to restore.

The reason taking a whole system approach is essential in assessing the use of ALL soil amendments (both mineral and biological) is because soil is a complex ecosystem. In complex ecosystems there are many interrelationships between interconnected parts and the consequences of our actions can be separated from the action itself in space and time. A change in one area can often lead to unintended consequences arising somewhere else, sometimes many years later. 1+1 may not equal 2. Emergence is built into natures design. Unexpected things emerge in natures complex ecosystems. Imagine we are seeing an egg and a chicken for the very first time. We wouldn’t expect an egg to come from a chicken by only examining the egg in complete isolation from its relationship with the chicken!

When we take a linear approach to investigating any soil amendment, we fail to pick up the unintended consequences of our actions. One example of this is the dead zones in our rivers and oceans that have been created by the runoff of fertiliser nutrients and pesticide residues upstream. Another is the declining carbon level in agricultural soils that have reduced the ability of soils to hold and store water that is creating desertification. We miss seeing these unintended consequences when we focus our attention only on the short-term response at the initial place of our well intentioned actions. When we look for responses from a product application, we can also easily miss the benefits of using biological amendments intended to restore soil health if we are not looking at the whole system over a longer period of time.

Factors to consider when we decide to try a soil biological amendment in our system to take a whole system, longer term view are:

You can’t buy soil health in a bag. Management is the foundation, not inputs. Without changing our management practices, we end up on an input addiction treadmill with ever increasing rates of application required to bring about a noticeable response as the health of the soil continues to decline.

“There is no system of production or soil amendment that will fix what is wrong with your soil. You must become a student of what makes soil healthy. It’s that simple and there are no short cuts.”
Jon Stika, A Soil Owner’s Manual

Soil biology needs a home to survive. We must build the home first. Without a habitat conducive to the survival of life, with air, water and organic matter to insulate from temperature extremes, soil biology cannot survive. Management is how we build a habitat for soil biology. We can’t buy soil structure, aeration, water holding capacity or health in a bag or a drum. Soil health restoration starts with restoring living ground cover, building the roof of the house. Managing this living ground cover through grazing and cropping decisions that prioritise capturing solar energy through photosynthesis to improve soil organic matter builds the walls of the house. Once we have built a roof and walls soil microorganisms have a habitat in the soil and can fulfill their role in assisting soil aggregates to form and build spaces for air and water to flow through so soil biological processes can start to function again.

Patience. Restoring soil health takes time, there are no quick fixes because it is our management that builds the foundation. Soil health restoration requires that we commit to a change in management practices for a minimum of three – five years, maybe longer in some contexts.

Understand the purpose of different types of inputs. Fertilisers, biological stimulants and biological inoculants all have completely different purposes. Comparing a biological input with a fertiliser application is like comparing apples with bananas. Check out the learning resources listed below on understanding biological inputs to make sure you understand the differences.

Measure soil health holistically. Don’t rely on soil mineral analysis in isolation. Soil health is comprised of soil physical, biological and mineral health. Undertaking yearly soil visual health assessments to monitor soil physical health for changes is essential. Conduct mineral analysis if you wish (every 3-5 years to see if there are changes in the minerals that rely on soil biology to cycle and function in nature) however the soil physical health is THE most important factor to monitor over time. You might decide to monitor soil biology through soil food web laboratory analysis (every 3-5 years), again this is most meaningful when done to complement monitoring of soil physical health. Soil physical health is a simple, cost effective and reliable indicator of what is happening with your overall soil health trends over time that you can do yourself.

One effective way to incorporate a longer term, whole systems approach to trying new ways of restoring soil health is by establishing a let it grow area. Instead of short-term trials of biological inputs with no change in management practices, consider allocating a specific area of land where you can afford to allow a longer-term approach of 3-5 years to experiment with a different approach. A let it grow area where you can change your management practices and build a home for soil biology to thrive along with incorporating biological stimulants and inoculants. A let it grow area will show and tell you way more than only throwing inputs around. This approach reduces the financial risk and can grow your confidence to successfully implement strategies appropriate in your unique context on a larger scale.

Soil biological inputs work when they are integrated (not separated) into a soil ecosystem where there is a web of diverse, interconnected relationships. Regeneration is first and foremost about replacing mechanistic, reductionist methods which rely on prescriptions with a holistic, living systems approach based on principles applied in context. The first step in a successfully restoring soil health is to regenerate our mindset and make management decisions about how we will capture sunlight through photosynthesis to restore soil carbon, the building block of soil physical, biological and mineral health of our soil.