- Two ways to feed plants or kill them and pollute groundwater.
- The Nitrogen plant food in mineral fertilisers is soluble in rain and leaks into groundwater and rivers.
- Mineral fertiliser-based farming is unsustainable.
- There is an alternative.
By Bill Butterworth
8 February 15
There are two ways plant food or toxins can get into a plant. The first way is in solution and that route is described here. If a chemical, natural or manufactured, is dissolved in water, that material can get into the plant or be leached into groundwater. This applies to fertilisers, wastes from industry or what comes out of the well from fracking.
If you are not a trained chemist, don’t worry, you can still follow this logic.
In modern farming based on mineral fertilisers, the nutrients get into the plant mainly in solution. Mineral Nitrogen is manufactured by pumping air through a large, maybe 2 m diameter, continuous electric arc. The temperature of the arc is enough to make the Nitrogen gas (which at normal temperatures is inert) react with the Oxygen in the air to form Nitrogen oxides and that is the starting point in manufacture of ammonium nitrate, one of the world’s main sources of Nitrogen fertiliser for food production. Unfortunately (and unsustainably), even in a modern and relatively efficient USA factory, this process will take around 21,000 (yes, twenty one thousand) kWh or “units” of electricity to make one tonne of mineral Nitrogen nutrient, which is almost exactly 3 tonnes of ammonium nitrate. And, in normal farming, around 35 to 45 % will be washed into the groundwater by rain. Or irrigation. Neither the manufacture nor use is sustainable. (For further details, see “Reversing global warming for profit”, by Bill Butterworth, published by MX Publishing, 2010, London.)
Above is a diagram of how this works. It is an extract from my book, “How to make on-farm composting work”, published by MX publishing.
Clay will hold on to some of the Nitrogen if we do not apply too much at once. On clays, maybe 30 % or more will be lost to groundwater. On sands, that figure will rise to over 50 %, especially if irrigated.
When I was a student (in Agricultural Science), and it was 50 years ago, we were told that “we have the power, we have the chemicals and we can deliver anything we want”. It was substantially true. My generation has developed the technology to feed the world – provided, that is, that they stop breeding. The problem was and remains that such systems are not sustainable and we are destroying the planet that feeds us. What we left out all those years ago was the biology. We now know how natural eco-systems work and we can mimic them sustainably.
This logic can and does apply to what comes out of the hole when drilling or oil or fracking unconventional, or shale, gas.
Watch out for the next blog in this series. It will show how such pollution is avoided and shows the mycorrhizal (soil fungi) conduit which is the central mechanism in what is commonly referred to as “the closed loop”. It is the mechanism which stops leakage which causes pollution of ground water. It is this very same mechanism which feeds plants and protects them from disease.