Hydroponics

Back in the 1940s, Eve Balfour wrote a book called The Living Soil that became, along with Sir Albert Howard’s An Agricultural Testament, the bible of the organic movement.  Albert and Eve were going to call farming in harmony with nature ‘Biological’ farming, but J.I.Rodale, Eve’s pal in the US, persuaded her that ‘Organic’ was a better name.  Organic farming is biological’  farming in that the carbohydrate produced by plants fuels the biological engine of microbes, worms and other creatures in the soil that converts soil nutrients into food for the plant.

So…what happens when there’s no soil involved?

When hydroponic farming came along, the organic movement was divided.  How could we not grow things in soil and call them ‘organic?’  The proponents said that hydroponics mimicked soil by using peat or coir as the growing medium, infused with water and organic nutrients.  The Soil Association allows peat and coir, but only for starting plants out or to improve soil, but not as a growing medium on its own. So as hydroponics wasn’t ‘soil’ it wasn’t approved. The EU organic regulations also prohibit hydroponic growing.  However, the US organic regulations do allow hydroponic growing. They require that the nutrients are organically approved and no pesticides or other prohibited inputs are used.  It’s what they call ‘bioponic’ – in other words as long as the biological activity is the same as in organic growing, where microbes in the soil interact with nutrients and plants, it is the same, functionally, as growing in soil.

We have an equivalence agreement with the US that allows the import and export of organic foods even where there may be some differences in regulations.  This is one of those differences and it’s now being reviewed on both sides.

I should declare my interest.  Our company Carbon Gold sells soil improver to organic greenhouse growers who benefit from the benificial biological impact of enriched biochar which encourages the active microorganisms that typify healthy soil.  It does it by providing a huge surface area that enables them to flourish.  With it they can grow tomatoes avoid suffering from soil-borne diseases.  But we also sell much more to non-organic growers who value the fact that, whether combined with coir or peat, biochar’s biological boost enables them to reduce or eliminate pesticide use and enjoy higher yields, by plugging in to the ‘soil food web.’   So I’m walking both sides of the street and ‘conventional’ growers are reducing their dependency on pesticides and inputs.

Farmers who grow hydroponically and using biology are getting yields and quality up, too. It’s reached a point where a grower in Holland can get 80 tonnes of vine tomatoes per hectare, a 10-15% increase, by working with biology.  It would be unfortunate if branding such as ‘pesticide-free’ or ‘LEAF’ were to predominate with consumers who just want a ‘clean’ product that is free of pesticide residues.  Most aren’t bothered if the roots of the plant were in soil or instead in some kind of soil-like mixture off the ground.  They just don’t want to eat pesticides.  Strawberries, cucumbers, peppers, lettuce and salad crops all perform brilliantly in controlled situations. Performance equals competitiveness.

 Organic growers use peat in greenhouses and also steam sterilise their soil between growing seasons.  This raises ecological and biological questions that are uncomfortable to answer.  With ‘bioponics’ you recreate the biological conditions of growing in soil, but in troughs that allow at least 180 litres of soil per square metre – this means ‘feeding the soil’ rather than ‘feeding the plant’ and looks like it may be the compromise way forward.  For the past 5 years I have been growing vegetables (for my own use) in my greenhouse in troughs 2 feet off the ground that contain 400 litres of homemade soil per square metre.  I use the same troughs in the spring to propagate healthy plants that are then planted out and sold as Soil Association certified.  And I’ve never had to steam sterilise or use peat.

This affects everyone.  When you go into a supermarket the first thing you see is fresh vegetables.  In Denmark fresh fruit and vegetables are 30% of the organic market. The same proportions apply in the UK.  25 years ago, when organic was first making headway the only organic products supermarkets bothered with were fresh produce. That’s because people are most passionate about organic when they are buying fresh fruit and vegetables.   If organic vegetable growers lose ground because they can’t take full advantage of the clean growing breakthroughs in biological technologies and pest controls then they’re not the only ones who will suffer.  The entire organic marketplace will be weakened if consumers start to choose non-organic ‘clean’ fruit and vegetables.  Once consumers have weakened their commitment to the organic ‘brand’ it can have unwanted repercussions on all their other purchasing. 

So the transatlantic debate about hydroponics, bioponics and earth affects us all, not just vegetable growers.