Are SoilFixer products organic?

The answer is yes.

But for those conversant with the organic movement lingo and legislation, we need to explain the difference between an organic product and inputs for use in an organic growing system.

Recently our friends at Garden Organic blogged about the new EU legislation covering organic production and labelling (EU 2018/848). We thought it timely to give an overview of how the legislation affects SoilFixer.

Can we label SoilFixer products as “organic”

No – this is because the legislation defines an organic product as the output from an “organic production system” (think farm, grower) destined for human consumption (for example, in the photo, labelling apples are organic).

The relevant question for SoilFixer customers is:

Can SoilFixer products be used in an organic growing system?

Yes – 100%! Our products come under the definition of an “external input”. For an “external input” to be used in an organic growing it must be “natural or derived from a natural substance” (see Article 5, para (g), (ii and iii)). Biochar, our compost humification agent and SF60 are all derived from natural materials – i.e. wood and green waste composting systems.

Note: the organic grower has to demonstrate that any external input is necessary and conforms to the overall principles of organic growing.

The core principles of organic growing  (Article 6, para (a))

• Maintain or enhance soil life
• Maintain or enhance natural soil fertility
• Enhance soil stability
• Help with water retention
• Enhance or maintain soil biology
• Prevent the loss of soil organic matter (SOM)
• Prevent soil compaction
• Prevent soil erosion
• Provide nutrients through the natural soil ecosystem

A quick look at the biochar, compost activator and SF60 product information will confirm that our products supports ALL the core principles.

They also qualify under Article 6 para (c): “inputs from recycling waste plant and animal system”.

Are SoilFixer products accredited for Organic growing, eg via the Soil Association?

No, not at this stage. The accreditation schemes seek to audit that your production system meets the organic definitions and you follow the rules.

To date, most customers have been happy to use the product specification and details of production as evidence. EU2018/848 seeks to enhance the evidence within the whole organic supply chain.

We will monitor the situation as it may become easier to prove this via a badge.

How to use biochar for healthier trees and woodlands

As many as a third of all new trees planted are likely to die within the first two years (reported via Independent and other studies). Many mature specimen trees of local and national importance are suffering health issues due to compacted soil. Many urban trees suffer disease and pest issues due to soil conditions limiting the tree’s ability to fight off disease and pests. In this article, we answer questions about how biochar is being used by professional trees specialists (arboriculturists) and woodland managers to help solve these tree problems.

Uses of biochar with trees

• Adding biochar to the root zone of older specimen trees revitalises growth by reducing soil compaction and poor nutrient availability.
• Adding biochar into the planting hole or pot to help new tree rootstock to thrive and avoid disease
• Using biochar to help establish a ‘woodland soil ecosystem’ in a prior meadow or cultivated land soil ecosystems.

How does biochar help improve tree health?

We handle the wider topic of how biochar works in our full article on biochar. In summary, it helps trees by:

•    The carbon adsorbs nutrients acting as a reservoir for plant nutrients.
•    The biochar is porous and holds both air and water.
•    The granules do not compress, so it aids irrigation and airflow to the roots.
•    It acts as a ‘home’ for beneficial microbes and fungi. These form symbiotic relationships with root hairs and dramatically increase the uptake of nutrients.
•    The biochar does not decompose, so it lasts hundreds of years.

Biochar works best when it is in and around the root zone.

Mature specimen tree care using biochar, reducing tree soil compaction using biochar

A specimen tree could be anything from the glorious cherry tree that blossoms each spring, the Acer full of colour in Autumn to the ancient oak that has stood in the village for hundreds of years. If you are entrusted with the care of a special and often irreplaceable tree; care is needed.

The more mature the tree, the more likely health issues will be related to soil compaction which leads to problems with water infiltration, nutrient availability and aeration. This leads to stresses that limit tree health and makes them more vulnerable to disease, drought and waterlogging. The early evidence is biochar can help revitalise trees, so it is worth considering.

Biochar can be a significant help – but the solution needs to be down in the root zone.

A range of innovative solutions to get biochar into the tree root zone has pooped up in recent years. These include using air-spades to remove all the soil and then putting it back. There is also an advanced form of air injection to drill holes and backfill the hole with biochar (e.g. the Vogt injector supplied in the UK via Apex Tree solutions). A high-pressure drill hole is made 1m deep and then 100 psi air is pushed down. This breaks up the soil. The voids created are then backfilled with porous biochar enriched with nutrients. There are even more complex multiple drill systems such as the Ecosol Drill ‘n’ fill machine.

In all cases – you are looking to avoid damaging the main roots. Most projects start in the active root zone – a circle around the drip zone of the leaf canopy.  If you are going closer to the trunk – drill slowly and watch out for any signs of white wood coming out with soil. If this happens, stop immediately and move the drill hole by 30 cm.

Improving tree planting success rates – biochar for new trees

Whether you are planting just one tree or many hundreds, the cost can be anywhere from £10-£300 / tree. As many as one-third of new trees are lost in the first couple of years. Giving them the very best start on planting is justified.

Dig the planting hole and then mix 10-20% by volume of biochar into the backfill soil before using it to backfill the planting hole. You can reduce the cost by adding a thin (1-2cm) layer in the base of the planting hole – but the effect will also be less. DO not get tempted to add more than 20%. Biochar affects soil texture – too much will start to impede rather than help growth.

Biochar for 3-10-year-old woodlands

Over the past 10 years, there has been and continues to be planting of new woodlands. A lot of these have been sponsored via one of the various Woodland Trust schemes.

There are some cases of top dressing by simply broadcast spreading biochar– but the benefits are going to be less than getting to the root zone.

Often these new woodlands will have 100-1000 trees. All fairly small and tightly packed (pending thinning). Not easy to get equipment in and around, and very labour intensive to do in via single drill holes. We think there is some scope to investigate re-using equipment designed for golf lawn care (e.g. the Ecosol Drill ‘n’ fill). These machines tend to be smaller and drill multiple holes. We will monitor for reviews and feedback.

New Woodlands – soil ecosystems

Quite often new woodlands are planted in grassland (meadows) or previously cultivated arable plots. We often see a grass field drilled and planted with saplings plus a stake and a green plastic shield.

This reminds us of the advice from a former colleague who was trained in permaculture. Soil ecosystems adapt to support the plants living on them, Hence grass and weeds have different fungi and microbes to woodland soils.  Planting trees in a meadow leaves trees roots in competition to the grassroots. We recommend tree planting of this type is supplemented with WOODLAND specific strains on mycorrhizal fungi (AMF)

There are many articles about the use of wood chips to help new woodlands.  A good article on the types of wood chip and their uses is presented by Linda Chalker-Scott. Whilst a lot of the focus is on water retention and preventing weed growth, we think there might be another benefit.

We are passionate that biochar supports soil microbes and fungi. It may well be the biggest effect they have is to support symbiotic fungi and give them an advantage because the porous structure gives them a defensive wall against predators that would otherwise eat them. If we extend this argument – well-rotted wood chip (at least six months old – do not use the raw new wood chip for mulching – it will hold onto your soil nitrogen) will have wood-based fungi. You are spreading a forest floor ecosystem that supports trees rather than grass.

Activating biochar

Don’t forget, raw biochar will adsorb and hold plant nutrients. This is what you want to happen as the soil microbes then inhabit the biochar and form symbiotic relationships with roots to transfer the nutrients to the plants.

However, to prevent short-term leaching of soil nutrients from the soil (and hence temporarily reducing availability to plant roots), you need to activate the biochar. Activation really just means filling up the adsorption sites with nutrients. This can be achieved by soaking the biochar in a dilute liquid NKP solution or by mixing the biochar with compost and leaving it to rest for a few weeks.

(Note SoilFixer has a proprietary method and product for activated biochar – SF60, our biochar super compost. We mix the biochar into the green waste with trace minerals allow it to compost under controlled conditions. The SF60 has a high % of colloidal humus. The humus accumulates in and around the biochar, not only activating it but radically changing the water retention and CEC properties. We call the activation agent our ‘compost humification agent’ and the resulting product is called SF60 Super Compost /Soil Improver.

Some case studies

Dr Glynn Percival: biochar helps prevent ash die-back. (As featured on BBC Countryfile)

Mattias Gustafsson: use of biochar to revitalise urban trees in Stockholm Biochar Project.

Giant sunflowers are grown using biochar super compost

We planted our sunflowers (Russian Giant) into the test beds very late this year, in early August, after the Charlotte potatoes came out. The thinking was simple; sunflowers need lots of water and nutrients and they will really test the different soil additive mixes.

If you have followed the earlier posts on potatoes and radishes, then you know we have five soil test beds.

One clayey soil (control), clay plus our super soil additive (code named SF60), clay soil plus compost from our HOTBIN®  (i.e. high colloidal humus compost), clay soil plus raw biochar, clay soil plus ‘shop’ bought compost.

The SF60 Biochar Super Compost (Soil Improver) formulation has resulted in 2.7m high Sunflowers and the earliest flower heads. They are 32% taller than the average.

The sunflowers grown with soil plus ‘raw biochar’ were 1.6m height. Those using compost from our HOTBIN® and shop compost were equal at 1.8 and 1.9m. The control is interesting; it is currently 2.2m – but!

The clay control sunflower has a fascinating story. A few weeks back, I noticed the soil height in all the tests beds had dropped some 10cm below the top rail. Basically the soil had compressed since filling for the first time back in September last year. The decision was taken to top-up at end of the season with like-for-like mixes. Then my neighbour tore up a path of garden to make a new patio and offered me one tonne of soil.

I wheelbarrowed it all back. I was running out of a space to store it. I thought well it’s same clay soil as the control – it won’t affect things if I add the extra soil in to one bin now. How wrong was that!

At the time of addition (four weeks ago) the clay soil sunflowers were second to last place.

But four weeks later, one week of heavy rain and two weeks of fantastic late summer sunshine and bang – they caught up the best performer. I’m pretty sure this is all down to water. The extra clay not only holds water; it has stopped the layer below drying out as fast – they had more water than other tests beds.

So this brings us back to the test.

The sunflowers tests indicate water retention within the soil additive as one of the most critical features, especially when looking at flowers in the late summer months.

Those who have read up on biochar as a soil additive will be asking – but surely biochar holds water. Why did the Sunflowers in biochar do poorly? Surely compost also holds water?

All these are true – the key question is “how much water (holding capacity) and, in terms of the biochar article, how long for (water retention time)”.

Why Does Biochar Super Compost work?

Consider this table of soil raw material properties:

Compost and biochar improve poor soils. Colloidal humus retains a lot more water. Just as importantly it holds onto to it for far longer. Compost dries at 100C in about two hours. A similar size colloidal humus sample would only be dry after 8-10 hours – it just doesn’t let go!

Not sure? You can try for yourself by taking 100g samples of BBQ charcoal, compost, clay soil. Wet them, roll into a ball in palm and leave them out in sun. Every hour check to see if they fall apart or are still pliable. The alternative is to use the kitchen oven to dry – but best check first. We might know all germs are killed within minutes at 100C, it still doesn’t mean the cook will be happy.

Colloidal humus is remarkable stuff. Even small amounts have a profound impact on soil. So why not just add loads of colloidal humus to the soil. Well, you need balance. Pure Humus is a sticky mass full of water. It does not let the soil breath (roots need oxygen). In essence, the soil needs more colloidal humus, but not too much!

What we are attempting to create with SF60 is the world’s best, (completely natural and sustainable) soil additive. OK we know that’s a huge goal for a small team, but we are very close. Want to test for yourself? Buy SF60 here!

PS: want to know how not to grow tall sunflowers? Plant seeds direct into poor clay soil, next to shed (shaded for part day and protected from rainfall. Leave them to fend for themselves and compete with weeds. Do not provide extra water. The seeds we planted have been in twice as long as those in test beds (16 weeks versus eight weeks). They are pathetic weaklings at 0.3m height and no signs of flowers. That’s a huge eight fold smaller. Nature has such huge capacity to change plant growth!

This blog was updated in March 2023 to reflect latest information on the new SF40 biochar multi-purpose compost.

SoilFixer has been supplying Biochar and SF60 (Biochar Super Compost) for many years. Our biochar-humus-rich compost is added to your topsoil to improve soil health and plant growth – it’s the closest means yet for you to make your own Terra Preta!

Many customers grow plants and vegetables in raised beds, containers, planters, and hanging baskets using “all-purpose compost” rather than soil.  (We are not fans of using the term compost to describe a soil-less growing media (mix) – especially when very few of the growing media mixes use any green waste compost. Most are formulations of peat/coir/wood fibre!)

Our goal is to find a better-performing raised bed mix that is also environmentally friendly – not just peat-free, but actually carbon negative (i.e. it locks carbon into the mix for hundreds of years). With a bit of annual care, our mixes should not need replacing each year.

Below we cover our journey to date.

Raised bed and container mix challenges

Container mixes present special challenges – they lose water and dry out faster than soil and the roots have a limited space to grow.  If you add lots of material that holds water (e.g. clay or humus), the mix can become ‘airless’ which restricts the root even more leading to stress, and disease problems like damping off (stem rot). It is not easy – ask any of the big growing media companies who have spent millions working on peat-compost alternatives.

We have been using our knowledge of compost, biochar, soil, and colloidal humus to create a fantastic raised bed container mix. We have looked at two routes: adding SF60 to the soil, and creating a wholly new mix from biochar and compost (now called SF40).

We tested the two options last year:

• Raised bed one: two parts finely sieved PAS100 green waste compost, 1 part SF60, to give a 10cm layer on clayey soil base
• Raised bed two, two parts PAS100 and 1 part biochar, 10cm layer on clayey soil base.

The differance is SF40 is a mixture, SF60 is made by co-composting biochar with green waste, then sieving the final compost-biochar mix.

SoilFixer raised bed mix benefits

Both work extremely well – giving 100% increase in plant growth. There are differences in water retention and growth in different plants towards the end of the season.

• Enhanced growth results
• Strong water retention and resistance to drying out
• Good re-wetting ability
• Viable cost for the “biochar raised bed mixes”
• Re-usable year on year (with some minor care)
• 100% peat-free
• Climate positive – unlike other raised bed mixes, biochar-based will lock carbon for +100 years

What next?

• SF40 is our preferred option for supplying a growing media – in part because it is much easier to make and control
• We need to test SF40 at a much larger scale… ongoing
• We believe SF60 will be the default for soil improvement