The cost of nitrogen fertilizers is rising very fast. The reason for this is that 90% of the cost of ammonia (a form of nitrogen) is determined by natural gas prices. Production of nitrogen fertilizers currently accounts for 5% of natural gas consumption. As the cost of natural gas rises, the cost of fertilizers will also rise. Many farmers rely heavily on nitrogen applications to boost production and maximise crop yields. Nitrogen is applied in the form of urea, ammonium nitrate, ammonium sulphate and water-based liquid nitrogen.

Nitrogen manufacture captures naturally occurring nitrogen from the atmosphere, combines it with hydrogen from natural gas under conditions of extreme heat and pressure. The end result of this process is anhydrous ammonia.

Chinese farmers apply nitrogen at the rate of 18.7 square metres per acre per annum. In the USA the rate is 9.1 square metres. Farmers in France use 2.5 square metres and most other European farmers use about 1.5 square metres per year. World-wide, 120 million tons is used each year*.

It seems that the usage of nitrogen as a form of chemical fertilizer and changes to the global nitrogen cycle, poses a growing environmental and public health risk. Since 2006, application rates are being increasingly controlled in the UK and USA.

High application rate of nitrogen fertilizers in order to maximise crop yields, combined with high solubility of these fertilizers, leads to leaching of nitrates into groundwater. When nitrogen is applied at a level, that exceeds crop needs, what is unused dissolves and finds its way into groundwater. Eventually it makes its way into lakes, bays and oceans. The presence of nitrogen accelerates growth of algae causing loss of oxygen in the water and producing an environment that favours plants over animal or fish life. Deprived of oxygen, the water dies. It is estimated that half of all USA lakes are eutropic (dead from lack of oxygen) and the number of oceanic dead zones near coastlines is increasing rapidly.

If nitrogen applications were to be stopped, it would take decades before accumulated nitrates in groundwater could be broken down and eliminated by natural processes.

According to the Ecological Society of America "increased production and use of chemical nitrogen poses a growing public health risk." Excessive air and water-borne nitrogen is linked to respiratory ailment, cardia disease and several cancers.

Blue baby syndrome is caused by the inability of the blood to deliver enough oxygen to the body. Nitrate is converted to nitrite, reacts with haemoglobin and turns it into methemglobin, a form that is incapable of carrying oxygen. Blue baby syndrome occurs in areas where the nitrate content of drinking water is too high and babies are bottle-fed and is a well-documented effect of exposure to elevated levels of nitrate in drinking water.

The same nitrate to nitrite conversion process in the stomach leads to the production of compounds called N-Nitroso. There is a substantial body of literature that suggests that high nitrate levels in drinking water may increase cancer rates. **

A Danish study has shown that nigh nitrate levels in drinking water contributed to the development of a condition marked by enlargement of the thyroid, the gland responsible for many of the body's endocrine and hormonal function.

At least five studies have shown a link between birth defects and exposure to nitrate, nitrite and N-Nitroso. This was first observed in animals, but has also been observed in human studies. ***

I am certain that most farmers don't deliberately set out to damage the environment or the health of people in our community but that is what they have been doing because chemical fertilizers like urea are easy to use and dramatically boost yields. Perhaps one of the benefits that will come from rising oil and natural gas prices will be reduction of nitrogen applications by farmers and a return to more environmentally friendly forms of fertilization.

*References:
*Galloway,
James et al "The Nitrogen Cascade"
**Mirvish, 1983, 1991
***Darsh, 1983

Linguini with wilted rocket,
pine nuts
& shaved parmesan

Ingredients 500 grams linguini
4 cloves of garlic
4 tablespoons of olive oil
150 grams of rocket leaves
1 cup of grated parmesan cheese
½ cup of pine nuts
Salt and freshly ground pepper
Chopped fresh parsley

Method
Add linguini to salted boiling water and cook till pasta is just tender. Drain.
Remove skins from garlic cloves and crush. Heat oil and add garlic. Remove oil from heat and allow garlic to cook. Toss hot garlic oil, rocket leaves and salt and pepper into the hot pasta. Add cheese, pine nuts and parsley and serve.

Rocket with potato salad

Ingredients
2 kg potatoes
2 cups of washed rocket leaves
½ cup of pistachio uts
5 tablespoons of olive oil
3 cloves of garlic, peeled and crushed
½ cup of grated parmesan cheese
1 tablespoon of unsalted butter
1 handful of rocket leaves

Method
Peel and cut potatoes into pieces. Steam till just tender. Drain and toss in butter. Make pesto by processing the rocket, pistachio nuts, olive oil and garlic cloves. Chop rocket leaves. Add pesto to potatoes and toss.

Meeting the Challenge

It is becoming increasingly clear that the bio-nutrient growing techniques we teach, which concentrate on simultaneously building soil biomass, high levels of organic matter and highly mineralised, balanced soil are going to be needed to feed the world's population. The techniques we advocate provide an answer to many of the world's most challenging problems:

• When compared with commercial agriculture, they use about 5% of the energy needed for each unit of production and are far less reliant on oil.
• On a small area of land they produce about five times as much as commercial agriculture.
• Water usage is about one-third per kg of food produced compared with commercial agricultural practices.
• They can be adapted to any location and any soil.
• There is no huge capital outlay required to get started.

Gowing our own food offers us the challenge of becoming partners with nature. When are you going to start?