By Ruth Anita Vaughan
REGENERATIVE agriculture (regen ag) is the new buzz in farming. Regen ag is an inclusive agroecosystems approach to conserving land and soil, biodiversity, and improving ecosystems services within farming systems.
It focuses on the regeneration of the living soil, improved hydrology (water movement and storage), and conserving biodiversity at all levels while enhancing input use efficiency. Simply put regen ag refers to farming practices that improve the environment with soil health and soil function taking a key role. Regen ag is not a specific farming system, but rather a set of farming principles:
- Minimise the soil disturbance.
- Keep the soil covered.
- Keep living roots in the soil.
- Maximise plant diversity.
- Maximise microbial diversity.
- Integrate livestock into the farming system.
And there are many different farming systems that incorporate these principles, including permaculture, synotropic agroforestry, many mixed farming and smallholder farming systems. Why practise regen ag? We have an increasing global population to feed and finite resources to do it with.
Modern agricultural practices have increased yields but at the expense of losing a great deal of soil fertility and previously productive land. Couple this with global warming and we have a looming food production crisis. It becomes paramount to use farming practices that are sustainable and maintain or improve soil health and yield potentials, while buffering against climate change.
What are we trying to achieve with regen ag? Healthy soil gives us clean air and water, bountiful crops, forests and grazing land, diverse wildlife and beautiful landscapes. Using regen ag principles in farming, farmers are sequestering more carbon, increasing water infiltration and storage and improving wildlife and pollinator habitat, all while harvesting better yields and profits. Being able to monitor the effect of different farming practices on the soil health is key to researching and building sustainable farming systems. A holistic look at soil health combines physical, biological and chemical properties of the soil. There are many ways and tools to monitor soil properties, and it can be confusing. It is important that any system used is useful, affordable, easy to interpret, sensitive to changes in the farming practices and that the results are consistent and reproducible.
Some of the tools available to us are as follows: –
Hands-on observation, touch, feel, smell.
Digging soil pits, looking at soil profiles, looking for insects, plant roots, soil clumps (aggregates), pouring water on the soil to get an idea of infiltration, feeling the soil texture and hardness. This is a more qualitative approach, which can be complicated and requires a high level of training, but it is free!
Laboratory analysis – samples can be taken and sent to a laboratory for analysis. Labs with ISO17025 accreditation have demonstrated that they are competent and generate valid results. Lab analysis is only suitable for testing properties that do not change when the soil is disturbed, for example compaction.
Lab analysis is only suitable for testing properties that do not change when the soil is disturbed, for example compaction reduces the minute you dig the soil.
Gadgets and apps can help us observe and test soil properties in situ. Soil moisture probes give us hydrology data, penetrometers measure soil compaction, there are soil health card apps, soil colour apps, slakes aggregate stability apps, and numerous apps to help us identify plants and insects. Microscopes open up the world of living soil to us that the naked eye cannot see.
Satellite imagery is especially useful to look at changes in land use, soil types and soil cover historically and through different seasons.
good to do a baseline study on the soil, to look at any risks or limitations. This will bring up any action points required to improve the functionality of the soil. On-going monitoring of critical soil properties (every 1-4 years) enables the farmer to know the impact of the farming practices and allows adjustments to keep a soil health plan on track.
Physical soil properties – Soil texture is impossible to change and can only be managed. Is the soil deep enough? Can your soil store enough water for the crop? Does it drain or will it become waterlogged? A professional physical soil map can be extremely useful for proper project planning.
Chemical properties of the soil can be measured from samples taken for single fields or on GIS points to create chemical soil maps for variable rate farming. The chemical properties should be measured in a lab. Measuring the pH, salinity, and nutrients will identify missing or excessive nutrients and enable the farmer to develop a proper soil health plan to maximise yields and minimise inputs. It is also recommended to check for heavy metals, pollutants, and pesticides.
It is crucial to measure organic matter and active carbon levels as these control many physical and biological soil properties. Biological properties of the soil are much more difficult to measure but extremely important. Macro fauna (insects) can be assessed through field observation and quadrant counting, but microbes cannot be seen with the naked eye, and it is estimated that there can be 50 billion in a teaspoon of soil! Looking at the soil under the microscope will give an idea on the microbial diversity on the soil but even then, it impossible to id most of the microbes.
Plating out on agar plates is time consuming and restricted. There is a great deal of exciting new, emerging technology for monitoring microbial activity and diversity in the soil. Soil respiration analysis measures the carbon dioxide released over time after the soil is dampened to activate the microbes and gives a very good idea on the biological activity and microbial biomass in the soil.
Some labs extract the DNA from the soil and run it against a database to give an idea of the quantity and species of microbes in the soil. Soil microbes are responsible for two main soil ecosystem services, namely filtering and buffering potential pollutants (detoxifying) and the recycling of nutrients (mostly carbon, nitrogen, phosphorous and sulphur).
Some of the most useful lab analyses look at measuring the speed at which these processes occur, others measure the enzymes produced by the microbes as they re-cycle the nutrients. Assessing soil health and developing a soil health management plan to improve and protect the soil fertility is essential to having sustainable yields and maintaining the health of our planet. It can be complicated! Sometimes it is better to allow farmers to concentrate on their core business and get a professional soil health consultant in to help!