Fossil Fuel Fertilizers v. Compost Teas on the Farm

Rebecca Hosking
Friday, 18th May 2012

Conventional fossil fuel derived fertilisers destroy soil life and wildlife yet they have become like a drug habit to farmers. Rebecca describes her head-to-head (or field to field!) trials with NPK versus homemade compost teas on the farm.

Around the home and garden you may know it as Miracle-gro®, Phostrogen®, Baby bio®, Growmore® or by one of its other fertile names. On the farm its many forms may be referred to as 'super triple phosphate', Nitram®, '20:10:10', just 'nitrogen' or – rather euphemistically – fertilizer. On our farm it's simply known as NPK, the acronym of this compound's most common chemical ingredients – nitrogen, phosphorus and potassium.

Synthetic fertilizer was essentially developed to stave off the limits to population growth and it's been estimated that almost half the world's human population are currently fed as a direct result of its use. But, this once heralded silver bullet for 'feeding the world' has certainly come at a cost; from vast oceanic dead zones to accumulation of heavy metals in our top soils to the release of greenhouse gasses into our atmosphere.

I'm not going to get into debating the global merits or otherwise of synthetic fertilizer but, when it comes to our farm I will slam my wellied foot down with some defendable authority because there is another obvious drawback of NPK and that is its lack of sustainability in the true sense of the word. The P (Phosphorus) and the K (Potassium) are both mined from depleting mineral sources and the N (Nitrogen) is pulled from the air using large amounts of natural gas or coal.

The field on the right has that aqua green flush only given by NPK

Our goal on this farm is to create an economically, ecologically and socially resilient business so the notion of relying on a depleting, fossil fuel hungry overseas resource as the basis of fertility on the farm is completely nuts. However, stopping using NPK is not as straightforward as some might think. Even my father who has been merrily spreading it on the fields for decades describes it as a drug and farmers like junkies for using it.

The drug analogy isn't a new one but I don't think many people know quite how fitting it is on so many levels. Like a narcotic, the first hit is the best and from then on you're hooked.

One of the reasons the first rush is sooo gooood is that you actually still have functioning living soils at that point so you are genuinely adding 'extra plant nutrients' to an existing fertile system. I often wonder what wonderful growth rates my father and uncle must have witnessed when they first applied NPK to our then organic fields, what a hit they must have seen.

Naturally, essential plant nutrients and minerals in the soil are taken up by the soil biology. As the saying goes, "Once the mineral becomes life, it's available to all life," meaning once a mineral has been taken up by a soil microbe it's then a plant available nutrient or available to support the life of another microbe.

The sheer volume and variety of microscopic life in healthy soil is mind-boggling. Just one teaspoon of healthy organic soil carries around a billion soil microbes. If you're familiar with the work of such scientists as Dr Elaine Ingham or Dr Patricia Richardson you'll have probably seen incredible electron-microscope footage of this wonderful underworld.

A glimpse of our underworld

It's a world full of fungal forests and peculiar plants, of bizarre little grazing herbivores that are prey to fang-toothed hunters that in turn are devoured by positively petrifying looking apex predators whose dead bodies are scattered by innumerable little scavengers. They are all their under our feet, unseen.

What's not so commonly known is when you first sprinkle on the NPK these microbes die off in their trillions with each tiny body releasing a small package of nutrients to the plant roots around them. To the naked eye we just see an impressive surge in plant growth but on the microscopic scale it is the apocalypse!.

The pitiful sight of the dead and dyingIf, like us, you're one of those farmers or gardeners without your own electron microscope, there is one soil dweller we can observe that can tell us all we need to know about the life in the soil and the effects of chemical fertilizers – the earthworm. We all know that a soil rich in earthworms is healthy and fertile so you can imagine how distressing it was to find dead and dying worms scattered across one of our fields during the first rains after the NPK had gone down.

Like an addictive narcotic, once you start using synthetic fertilizers, it is a one way ride. Each application onto to fields burns off more and more soil biology which in turn severely reduces the amount of available minerals and nutrients from the soil to the plants. Each year you have to add a little more just to stand still and eventually it's a case of add the NPK or go out of business.

Holistic Rancher Greg Judy sums it up by saying, "When you put chemical fertilizer down on your farm you're killing your farms future, and the fertilizer companies are laughing all the way to the bank because you've now got sterile soil, and they know you've got to comeback to them to buy more of their fertilizer."

That's the trap my father and uncle are seemingly in, the only way they view they are going to get any growth out of our fields is by mainlining a direct hit of chemicals straight into the plants roots because they no longer can rely on the now impaired soil biology to help grow healthy plants.

It is possible to wean your farm off chemical fertilizer but it's not easy – it's called 'organic conversion'. As any farmer who has made the move to organic can tell you, going cold turkey from synthetic NPK can be a painful business. Curiously it is not just the land that becomes addicted, the whole way of working the land changes and, in effect, the farmer is just as hooked as his soil.

Intriguingly over the last couple of years since we've started applying pressure for my father and uncle to stop using the stuff, that junkie farmer mentality has unwittingly risen to the surface.

The tale starts four years ago, Tim (my other half) and I sat down with my father and discussed the damaging nature of synthetic NPK. He completely agreed with us and promised not to spread it on the fields on the west side of the farm as a small trial.

The depressing shaker sound of the fertilizer spinnerThe following week I heard the unmistakable rumba-shaker noise of the fertilizer spinner... it was in the next-door field to me. Dad had purposely driven the long way round the farm to avoid driving past Tim and myself so he could 'fertilize' the fields he promised not to touch.

That was just the start or this behaviour; since then they've taken to hiding their NPK 'stash' behind the backs of barns in the hope we won't find it. Each year they may have got away with it if the deliveries hadn't been the same size as a grey whale.

They promise not to buy as much only to either buy the same amount if not more each year. Even the language they use sounds like an addict, "Oh I've only used a little bit", "I used to use a lot more then I do now – I've cut right back", "You're right we should give it up... but we've bought it all for this year now so we can't waste it".

The point being my father fully admits NPK is bad for wildlife and knows it damages the soils and is dangerous in waterways and doesn't like using the stuff yet, like a person with a habit, he'll go into complete denial when actually out scattering it on the fields.

The not so secret stashAs a result we realised pretty early on that if we were going to make any headway we needed to find an equivalent to soil methadone to try and wean the Old Boys off their magic white granules.

Our answer came in the form of cold brewed aerobic compost tea. Compost tea (or more correctly, we think, compost beer) has grown and grown in popularity over the past few years, particularly with gardeners but is now making headway into the world of farming. You can make it at home for next to no cost and, if brewed correctly, it's packed full of beneficial micro-organisms who then provide the  'fertilizer effect' by making biologically available those nutrients already present in the soil.

We started using it three years ago and risked a head to head challenge to prove to my father and uncle this bizarre alternative had some merit.

homemade compost brew bubbling awayMy father doused half a field in NPK and we sprayed the other half in compost tea. When it came to hay harvest time we all walked the two sides of the field to compare the results. Stupidly I never took any photos that day but although the sward wasn't as heavy with the compost tea it still held its own to the fertilized side. Particularly seeing we made the tea for pennies compared to the hundreds of pounds spent on fertilizing the other half. As a result of that trial, the following year we were given the go ahead to spray an additional field and this year a couple more.

In our case, the biggest benefit from using compost tea was to stop the NPK going down which is essential if our soil life is to start building again. Rule one for regenerative agriculture should be the same as in medicine – do no harm! The added bonus of compost tea is that by adding trillions of beneficial microbes it should also be helping to jump-start the biological cycle within the soil.

Tim's made from scrap and less than £50.00 compost tea sprayer

There are some farmers we know of who swear by compost tea and apply it in quantity several times a year but, for us, we see it as a temporary measure. By changing our land management and grazing practices, we hope to rebuild a truly healthy, self-sustaining cycle of life in our soils powered solely by the sun. Compost tea application will definitely have a role to play in getting things started but hopefully we won't have to apply it for too many more years. To use a thoroughly inappropriate analogy, compost tea is our starter motor and we will only be using it until the main engine kicks in.

Useful links

PDF from Elaine Ingham on compost tea

Video clips of Paul Taylor on making compost

Teaming With Microbes - the organic gardener's guide to soil food webs reviewed by Patrick Whitefield.

Nick Bailey |
Fri, 18/05/2012 - 16:48
Thank you for this, recommended to me by Alys Fowler. I was struck by the similarity with using pesticide encapsulated seeds as investigated on Country File the week before last. There the farmer uses these 'seeds' which look nothing like - black pellets with some seed buried deep inside. The effect is that the seedling grows up absorbing this pesticide which then stops the aphids eating the crop. Now frankly there are hundreds of reasons why this struck fear into my heart (it's killing bees, it's killing aphids, it's killing who knows what else, and surly, if the pesticide is in the plant, in the flower, in the nectar then it's damn well going to be in the seed - which then ends up in us). But the similarity with this article is the addictive nature by which farmers are hooked on these industrial alternatives. I'd always assumed that farmers, like me, save 10% of their crop each year to sow again next year. But if the seeds are inert (F1?) then this is impossible. Or even if they are viable - you'd risk loosing the crop to the evil aphids - so best to pay vast sums for evil black seeds which promise an abundant crop. I'm really staggeringly worried about farming. For a long time I've been quite against farmers because I foresaw them as simply attempting to rape the land. But perhaps I'm wrong, perhaps it's the same industrialisation that is threatening the modern food chain by peddling processed foods into our children and weaning us of real whole foods. These industrial giants have not only got the supermarkets by the short and curlys, but also all the farmers supplying them - as you say, farmers are hooked and can't help but use more fertilisers and more pesticides. I think this is something that could do with the attention of Country File. Perhaps it's worth contacting Tom Heap. I really feel encouraged by this article, I truly hope we can wean ourselves off this mad cycle of over industrialisation of our land. I hope that the threat of a global population 9 billion will not stimulate further investment in agrochemicals, but instead simulate more like you to explore the natural alternative, so that we no longer need an 'organic' certification, but instead demand a 'non-organic' (or perhaps 'pesticide rich') label. (I also long for a 'non-fair trade' label). Thank you for your encouragement.
Peter Wadham |
Sat, 19/05/2012 - 00:53
A very good article. I agree with what you are talking about. When I started in Agriculture I did this too.I have talked to many people starting gardens and having started on the journey to convert to one of the organic systems. The number of times I have come across people who say to me we don't use sprays on our garden/farm. Then in the next breath they say that garlic and pyrethrum is very good at killing aphids. After some careful questioning I find that they have replaced all the "Bad" chemicals with "good" organic chemicals. When I challenge them, many just don't get it. I try to talk to them about system thinking. About how a tree drops its leaves on the ground which are broken down by larger insects and the left overs are broken down by smaller and the waste of one animal is eaten by another creature. Eventually this then gets into the soil and the bacteria, fungi and microscopic creatures break it down further. This process releases the nutrients the plants need. It also holds the nutrients until it is needed. I call this system thinking. It is thinking about the whole of the system rather than just part of it. Everything is linked. When we do something here it has an effect over there. To my mind the aim as a gardener/farmer is to get the system to the point where it requires minimal intervention from me.
Jim Thomas |
Sun, 20/05/2012 - 21:27
When we moved onto our land it was about as used and abused as could be, in fact it was degenerating into real desert, and our first compost was a cubic metre construction of greens and browns without any added manure which we positioned in the shade of a scraggy nondescript almond tree. That compost was very successful and kick started not just our garden but my interest in composting and so the next season we moved the location to a place that was more suited to larger batches. Anyway the point is that the almond tree leapt into life and grew vigorously over the following years, far outgrowing its neighbours, producing lots of new wood and good crops of almonds and aptly validating your point about kickstarting the fertility cycle. One good tip if you are using the basic barrel and aquarium aerator setup to make compost tea is to use a tea bag made from ladies tights thus eliminating the problem of clogging the sprayer. Then depending on how you like your tee you can have one leg or two. We also make a nice seaweed tea which is said to have hormonal properties. This problem of chemical damage to the topsoils prompted a great deal of research in the middle of the last century and works by such as Sir Albert Howard, G.T Wrench and Maye e Bruce amongst others can be read on the Journey to Forever online small farms library.
Maddy Harland |
Tue, 22/05/2012 - 06:42
Thank you Jim for the tip about ladies tights - very useful!
greenfinger |
Thu, 07/06/2012 - 19:57
Thanks for a fantastic heart felt article Rebecca. I just know so many farmers just like you describe! I have been using both nettle and Comfrey teas for a few years now and can certainly attest to their efficacy. There are a few points in your article I would appreciate if you could expand on which are rather intertwined so I will try and phrase it as clearly as possible. The first concerns organic fertilisers generally. Do not organic fertilisers, e.g. blood and bone, seaweed, animal dung etc in fact contain exactly the same N,P and K chemical constituents as chemical fertiliser and thus have the same negative effects on soil microorganisms as the use of chemical fertilisers you describe? Your description of the action of teas seems to imply they operate in a different manner to other "fertilisers". Perhaps I am confused here but I had got the impression that teas contain the same Ns, Ps and Ks as all the other fertilisers and this was the way they worked to promote plant growth. In particular I believe nettle tea is nitrogen rich and thus promotes leaf growth whilst Comfrey tea is Potassium rich and promotes root development and is particularly good for tomatoes and potatoes. This is maybe a bit simplistic but I would appreciate any light you could throw on the subject.
Liz Beavis |
Tue, 12/06/2012 - 06:36
We bought a farm that has cultivated areas that are addicted to fertiliser. We planted oats and used "organic" fertiliser, but of course this has been very ineffective, as there is no life in the soil (haven't seen any earthworms at all), the oats look terrible, but we don't want to keep feeding the addiction. It looks like we need compost tea, we just bought a spray boom for our tractor. I'm just wondering now about application rates, do you have any advice? If we make a 1000L container of tea, how much should we dilute it and how much should we spray onto 20 A? I realise that we will need to work this out by trial and error, I was just hoping for some rough figures to get us started. Thanks so much, I finally understand the difference between liquid manure and compost tea, can't wait to try it!
Patrick Whitefield |
Mon, 02/07/2012 - 19:49
To answer Greenfinger's questions. 1) Organic fertilisers may contain the same NPK as artificials but it's in an insoluble form, whether rock or an organic compound. It can only be made available to plants by the action of soil microbes. Artificials are highly soluble. They're immediately available to plants and are also harmful to soil life in various ways. 2) Aerated compost tea is not a liquid manure. It's a culture of microbes, made by bubbling air through water which contains a small amount of comost. This causes the beneficial microbes to multiply many times over. When applied to the soil or to the plants these microbes help in many ways, including by making insoluble nutrient more available to plants.
Сергей Трущенков |
Fri, 06/07/2012 - 10:37
Compost tea is probably a useful thing. But the matter is that it takes a lot of time to be prepared and nobody knows what kind of bacteria and funguses he grows. Together with useful bacteria there can live harmful fungi and other plant diseases in your compost. Instead of it you can take already done and guaranteed microorganisms which will work in the soil and on plants as fungicides and insecticides. Any harm, any lost time, any equipment. The whole you need is the biological preparation and water. To be sure visit the page Believe me you’ve never seen something better.
tedjevanasseldonk |
Wed, 09/01/2013 - 07:23
Rebecca and Tim, thanks very much for sharing your experiences. Saw the film and it was very very inspiring to us, as we had just bought a farm (7 ha, half of it woods) in Italy. It has been a conventional dairy farm so we see many similarities in your story. We are now in the process of making hugelbets and planting food trees and shrubs everywhere. We want to have only a few animals and concentrate on medicinal herbs & fruits & wild / forgotten vegs. Allthough permaculture is very popular on the internet now, most people are engaged with small scale (town) gardens, so we are glad that you try to get it going on a larger scale, just as we try to do. In fact we have nice(r?) neighbours being all hobby- or organic farmers and some are already working synergetic and permaculture-like. Pretty soon we will maybe have a kind of permiesgroup here. We'll keep you informed. Please keep on writing and ofcourse wishing you all the best with the farm!