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Clover Blog

How to Create Fertility without Buying Fertiliser

There is a common misconception in the farming world that’s harming your profits and potentially your future. We’re led to believe – in increasingly clever and technical ways – that we need fertilisers in order to increase the productivity of pasture or meadow. But just as humans aren’t ‘statin deficient’ when they have a heart attack, grasslands aren’t ‘fertiliser deficient’ if their performance is poor.

How to create fertility without buying fertiliser

The study of soils has come on enormously in the last few years. Before the 1980s, scientists had little idea that soil organisms were important to plant health, through the ‘green revolution’ agriculture has been dominated by chemical solutions. Now, due to recent scientific findings, I’m confident that the next wave of high production agriculture will be led by those who understand the biology of our soils.

Minerals come from rocks. Every soil in the world has the potential to grow plants. Some rock is weathered into soluble forms that plants can absorb directly through their roots and then are recycled back through the decay process – this is the ‘soluble pool’ that shows up in a soil analysis test. But how do we access the limitless ‘total pool’ available in the crystalline structures of the rock that can provide the full 42 of essential nutrients plants really need to be healthy and disease resistant?

This is where your underground army is required. Every spoonful of healthy soil contains a billion or more microorganisms. In healthy grassland there’s approximately the same weight in earthworm biomass as the weight of the cattle grazing above ground, not to mention the thousands of other tiny critters all shredding, digesting, dissolving and excreting to gradually improve your soils.

The mineral cycle is that; a cycle. But to understand it we should start – as the earth did – with bare rock and some bacteria, fungi and algae. These microorganisms use enzymes and acids to break down the rock and access the nutrients. With no soil in which to reside, the bacteria, fungi and algae form symbiotic relationships to create a plant-like species called lichens. These communities can then offer a home to mosses and lower ‘successional’ species. Gradually the cycle of growth, death and decay builds enough soil for whole plant communities to thrive.

The more complex the plant community, the better the overall access to the minerals in the soil will be. Different species have different root depths, soil preferences and water tolerance. The plant will grow deep roots if the foliage can develop mature leaf; this will help it access a higher concentration and wider range of the soluble nutrients. Minerals tend to leach downwards as rain passes through the soil layers; deep roots help transport minerals back upwards.

Dead plants, excretions from grazing animals and other organic matter pass some of these recycled minerals in a plant-available form back into the top layers of the soil again. But the real potential to make free fertiliser forever is in the so-called ‘microbial bridge.’

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When the sun shines, plants photosynthesise. The plant makes food, some for itself and the rest – 40%ish – is passed out of its roots as an exudate of sugar, carbohydrate and protein, or, as leading soil ecologist Dr Christine Jones calls it ‘liquid carbon.’

This juicy cocktail attracts and feeds bacteria and fungi that, through solubilising rock mineral, have a biomass filled with the essential nutrients our plants can’t access. In turn, these bacteria and fungi attract predatory organisms like protozoa and fungal-eating nematodes that eat them, releasing nitrogen, phosphorus, sulphur, magnesium, potassium sodium, iron, zinc and more, in a handy dandy plant-available form. The whole process takes seconds and conveniently happens right next to the plant roots where it can be easily absorbed – no waste, no leaching, just an ‘on tap’ source of everything your plants need.

But ... here’s the big but...

Most of the soils across the world – including the UK – are not able to make use of this miraculous free fertility. Because, frankly, we’ve knackered the system!

The biology in our soils is adaptable and resilient but some activities are catastrophic to our most important resource.

Inorganic fertilisers, herbicides, fungicides, insecticides, wormers, antibiotics, irrigation, tillage, overgrazing, monocultures or reduced diversity, and leaving soil bare are all hugely detrimental to our microbial army.

I recently walked the land with a cattle farmer who had noticed that the dung from some cattle she had bought in hadn’t broken down after three months on the pasture. The dung from her own herd broke down very quickly as she used no wormers or insecticides. She discovered the animals were treated with ivermectin not long before they arrived.

All wormers, insecticides and antibiotics are designed to kill; our soil organisms are an accidental victim. These pharmaceuticals don’t all break down naturally, so your muck or slurry could contain a cocktail of all the medication you have administered. You’re paying for it twice; once on the way in, once on the way out!

Inorganic fertilisers are also highly destructive to underground life. Nitrogen – even though it makes up 80% of our atmosphere – is a plant’s most limiting element. The stable triple bonded molecule makes it hard for life to access unless it is converted or ‘fixed’ into Ammonia (NH3). In a natural system, for nitrogen to be available to plants, it needs to be ‘fixed’ by nitrogen-fixing bacteria. This plant-available form of nitrogen soon gets gobbled up and, through the actions of a diverse soil food web - including bacteria, mycorrhizal fungi and their predators - is then recycled into different forms through excretions.

It’s now known that it’s not just legumes that are associated with the miraculous biological nitrogen fixing process; any green plants can be involved in exchanging liquid carbon for plant-available nitrogen. This process is very stable and happens ‘on demand’ with no leaching or wastage.

Pre-1868, 97% of all nitrogen-supporting life was fixed biologically and the only available form of manufactured nitrogen fertiliser was processed animal manures. Now only approximately 60% is provided through natural and biological processes. Through the development of the ‘Haber-Bosch’ process, it was possible to synthesise ammonia by combining atmospheric nitrogen with hydrogen under intense heat and pressure while circulating over a catalyst.

This changed the world forever and humans were no longer required to be part of a closed loop biological system – or so we thought. Over 100 million tonnes of synthetic fertiliser is now used annually; it has facilitated massive population expansion. Now, approximately two billion people rely on food produced from a high energy, unsustainable form of fertility.

Humanity is writing cheques our planet can’t bank!

If you use synthetic nitrogen fertilisers it isn’t helping YOUR bank account either. Up to 80% of applied fertiliser is lost and ends up in our water courses and eventually the ocean.

Nitrate runoff causes an explosive growth of algae which in turns sucks oxygen from the water as the algae decay. This sucks the life out of the seas, causing so-called ‘dead zones’, like that of the ‘Gulf of Mexico dead zone’ which extends over 20,000 square miles every summer due to the chronic overuse of fertilisers on farmland in Spring.

Even the small amount that remains to be utilised in your soil could be causing more harm than good. Every form of synthetic fertiliser disrupts the balance and damages the potential effectiveness of your soil biology. If your plants can gain easy access to soluble forms of applied nutrients, the underpinning biology doesn’t get its liquid carbon and dies off. Like a muscle that’s never used, it weakens and eventually can no longer perform well.

We know from long-running scientific field trials in North America that the application of synthetic nitrogen has other detrimental effects on soil health including depleted soil carbon, reduced soil water-holding capacity and a reduction in soluble nitrogen levels – yes, adding a lot of inorganic nitrogen means you have less available in your soil!

Fertility applications can have a potentially disruptive effect on livestock too. Even a ‘natural’ product like lime applied to a field is often in a ratio that is not optimal for the plants. It can mess with the overall balance of magnesium, calcium and sodium and can cause calcium deficiency in your foliage which translates into animal health issues associated with changes in magnesium and calcium levels.

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As leading Soil ecologist Christine Jones says, ‘inorganic nitrogen applied as fertiliser often ends up in plants as nitrate or nitrite, which can result in incomplete or ‘funny’ protein. This becomes a problem in cattle if it turns up as high levels of blood urea nitrogen (BUN) or milk urea nitrogen (MUN). Nitrates cause a range of metabolic disorders including infertility, mastitis, laminitis and liver dysfunction. There is also a strong link between nitrate and cancer. In some places in the United States, it is not safe to drink the water due to excessive nitrate levels. Milk can also have nitrate levels above the safe drinking standard, but people happily consume it, not realising it’s unhealthy’.

Other common modern agricultural practices such as ploughing and leaving soil bare have a hugely negative effect on the delicate yet essential mycorrhizal fungi strands which build soil structure, support the microbial bridge and are essential to effective water retention.

So how can you tell if you have a sub-optimal biology?

You can pay for a soil biology analysis, but the easiest way to tell is to see if you get a flush of grass when you use fertilisers or apply manure. If so, then your plants are not making their own fertility through symbiotic relationships; they’re waiting for you to feed them! Getting a strong plant response from a fertiliser application is a sure sign that there has been significant damage to your free fertiliser machine. In a natural ecosystem, plants can get everything they need all the time; you don’t see nitrogen deficient plants in natural environments.

It’s not that we’re taking more out of the system than would occur in nature either. Natural grasslands and ancient woodlands can support a biomass far greater than what we’re trying to achieve in livestock production today. Think of the enormous herds of wild herbivores that used to roam the earth and the mind-boggling diversity it could support.

How can we fix it and create fertility without fertiliser?

We’ve been taking our advice from those trying to sell products that are addictive, and have ended up playing with our farmland like it’s a Meccano set – this leads to many unintended consequences. Holistic management can help us better understand how to work with nature’s complex systems and maximise our most important asset. It’s the only long-term way for farmers to thrive.

In the UK and Ireland, farmers have a huge opportunity to maximise results from a tried and tested regenerative system developed in parts of the world with a less forgiving climate. Those who maximise their ecosystem processes can expect to drastically increase productivity and profitability with a few simple changes.

We need to keep the soil covered, minimise tillage and increase the diversity of species we grow. We need to ensure proper cycling of plant matter and enhance the conditions for soil microbiology through planned grazing that allows for optimal recovery and animal impact. We need to stop relying so heavily on harmful chemicals and medicines, and instead, learn how to minimise disease and pests through proper land and livestock management.

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Caroline Grindrod is a holistic management consultant who combines her skills in regenerative agriculture and environmental conservation. This abridged article was reproduced with kind permission from Caroline’s website If you’re interested in regenerative farming and holistic management please sign up to her mailing list or get in touch to discuss their training programmes.