Soil… the sustainable fossil fuel?

UK Agriculture continues to address the carbon conundrum after being labeled one of the main contributors to Greenhouse Gas (GHG) emissions in recent times. Although it’s fair to say Agriculture isn’t the main cause, there is no denying the fact it’s been a significant contributor. The good news is that Agriculture, or should I say the soil, has the capacity reverse global warming.

In the UK, ELMS (Environmental Land Management Schemes) is going to replace the Common Agricultural Policy (CAP) and will focus on public money for public goods. This means future payments will depend on management of landscapes, protecting water courses and reducing emissions. No bad thing. This emphasis on protecting the environment, however, means a rethink when it comes to everyday agricultural practices, again, no bad thing.

The last agricultural revolution, somewhat ironically named “The Green Revolution”, came after the second world war and saw a significant increase in the use of inorganic fertilisers and chemicals, however, the real Green Revolution is happening now. This time record-breaking yields, monocultures and increased fertiliser / chemical use will be replaced with improved efficiencies, the regeneration of lost top soil and the rebuilding of organic matter and carbon stored within the soil.

Fossil Fuels 

The world in which we live has finite resources. Fossil fuels are a prime example of this; millions of years ago fallen trees were compressed to form coal. Coal, like other fossil fuels, is stored carbon and energy and takes millions of years to make yet can be used in seconds. This finite resource is being consumed and is not being replaced. Luckily, technology has advanced and fossil fuels can been replaced with sustainable energy like wind or solar. Another form of energy generation is the soil. The soil has always been thought of as a medium to grow crops but it is so much more than that. Soil, and the plants grown from it, make the world in which we live habitable. The soil recycles carbon, nitrogen and other elements, and, by way of photosynthesis turns these atoms into apples. The soil can provide all the energy needed to sustain life indefinitely.

There are the same amount of carbon atoms in the world today as there was one million years ago, even one billion years ago. If we can return at least the same amount of nutrients to the soil as we take from it we will live in balance or harmony, its only when we upset this balance that things go wrong. The amount of carbon hasn’t changed but where that carbon is stored, has. It is thought that somewhere between 50 and 70% of carbon stored in the soil has been released by modern farming practices. This means that we are taking from our soils without returning anywhere near enough, or, eating the food in the fridge without every going to the supermarket to re-fill it.

The recycling of carbon throughout the soil, plant, animal, manure cycle is what sustains life on this planet and without it, life would look very different.

What can we do about it?

The understanding of this cycle and the increasing knowledge of soil science is showing us that agriculture can feed the world and that regenerative practices are sustainable and profitable.

When you consider 1kg of organic matter in soil can hold up to 4kgs of water and contains approximately 50% carbon by weight, increasing organic matter in soils by 1% would mean an increased water holding capacity of 160,000 litres/ha, and, a very rough figure of 40,000kgs/ha extra carbon would stored. This addresses the lions share of objectives set out by ELMs. Less flooding, less CO2 in the atmosphere, healthy soil, healthy ecosystems and plenty of nutritious food for a growing population.

If looking after soil and increasing organic mater, is the answer, then Bokashi is the solution. To support Bokahsi and reaffirm our beliefs, Agriton commissioned a three year trial comparing Bokashi to traditional composting and a control. The trial highlighted a number of positives with the results promising enough to extend the trial for another four years.

What is Bokashi? “Fermented organic matter”

Decomposition is the chemical breakdown of organic matter into its constituents by the action of bacteria and other micro-organisms. In other words, it is the completion of the soil-plant-animal-manure cycle and the returning of nutrients and energy into the soil for the next generation of living organisms to be grown. There are a number of different ways in which organic matter can be decomposed or composted.

Composting has received a lot of press lately, largely good, but a simple Google search highlights the large quantities of misleading advice and misinformation. This misinformation can be put down to personal bias or a less than full understanding of the decomposition process.

In Agriton’s opinion, which is now supported by the trial data, fermentative decomposition provides the greatest returns with minimal environmental impact compared to the accepted industry standard; aerobic composting. The trial looked at which method provided the best decomposed material to be used as a soil improver for the regeneration of soils as well as the carbon footprint of both methods.

The results

After three years the data showed that Bokashi increased soil organic matter over the control by 13.1% and by 10.6% over composting. In real terms a soil with a starting organic matter content of 2% would see a 30% increase in total organic matter and the ability to capture an additional 96,000 litres of water/ha. As well as this increases were also seen in Carbon, Nitrogen, Potassium, Phosphorus, Magnesium and Sulphur stored in the soil making it healthier but also more fertile.

Using Bokashi for three years also improved average yields and had less instance of disease and lodging compared to both the control and composting. When all the results were considered there was a significant amount of evidence highlighting the benefits of Bokashi and ensuring the trial was extended to further show the longer-term benefits of using Bokashi as a soil improver.

Of particular concern were the losses observed during aerobic composting. From the starting material (13,400kgs) aerobic composting lost 59% of the carbon or 2.3 tonnes of CO2. Comparatively Bokashi lost 3% of the Carbon or 0.1 tonnes of CO2 meaning Bokashi saved 20 times more Carbon than composting.

To conclude

Aerobic composting is not bad, Bokashi just happens to be more efficient. Returning nutrients, in any form, back into the soil is a good thing and will ultimately improve the soil health.

Bokashi has many benefits and thanks to farmers and growers there are now multiple way of establishing a Bokashi heap that fits into your system. There are, like aerobic composting, costs involved but making Bokashi is almost always cheaper and easier than aerobic composting.

There isn’t a one method fits all way of making Bokashi so it is worth speaking to an Agriton Advisor to work out the best way of introducing it into your farming or growing set up.

More information can be found on our Bokashi page.

Written by

Andrew Sincock