For every action, a reaction. For every good, a bad. This axiom is evident when considering “o rganic” food. While organic food is good, there is a cloud in the organic sky.

It takes a bit of explaining.

Nitrogen is a basic requirement for plant life. Unfortunately, the only nitrogen nature provides in usable form is from lightning strikes, rhizobium bacteria (which live on the roots of leguminous plants) and recycle organic wastes.

Lightning strikes are neither common nor programmable, there are only so many legumes grown in currently available land and there simply are not enough organic corn stalks or manure from organic cows to fill the world need for fertilizer.

World population growth and food production met on a collision course in the 19th century, when world population reached its maximum sustainable level, topping out at about 1.6 billion.

By then, the onset of world wide starvation was chillingly evident, and the word Malthusian entered our vocabulary. Consequently, it may be argued that the greatest scientific advance in human history was the synthesis of ammonia, a compound that delivers usable nitrogen to plants – a discovery that permitted the world to be fed.

In 1909, Fritz Haber, a German professor, discovered how to create ammonia. Shortly after, Carl Bosch, another German, developed a manufacturing process that made large-scale production of Haber’s discovery feasible. Haber-Bosch opened a new day for the world. Ammonia permitted human growth to today’s 6 billion.

Now we come to “organic food,” a food that must be grown without “chemical or artificial” fertilizer – in other words, nitrogen delivered by ammonia. So far, so good.

When the organic movement began, most producers were small scale. Rhizobium, lightning and cow poop were sufficient to meet demand. However, as the popularity of organic foods grew, so has the need for more land, and it becomes painfully obvious that a shortage of such land is upon us.

Stonyfield Farms, a large organic marketer, is now an industrial-type plant adjacent to an air strip in New Hampshire. It is planning to import powdered milk from New Zealand, 10,000 miles away, because there are not enough organic farms in New Hampshire or Maine to fill its needs.

And to add to Stonyfield’s problems, Kellogg, General Mills and, horror of horrors (or joy of joys), Wal-Mart, are entering the organic food market. Unfortunately, for all these markets, the U.S. simply does not provide enough organic grains to feed the cows, enough organic strawberries and organic sugars to make the yogurt, nor enough organic apples for pie.

Consequently, these companies are going afield (no pun intended). Even China, whose purity, it is reasonable to assume, might be suspect, is under consideration by organic marketers.

We might be able to produce enough food without hormones, insecticides, antibiotics or radiation. But without ammonia, the amount of land required to produce the necessary food for the world would rise well over 10 times. Such an increase would bring problems of transportation, ownership, management, labor standards, national boundaries, politics, religion, even war – to name a few. It would mean, for example, destruction of forest land that the world can ill afford to lose.

If Mr. Bush went to Iraq for WMD – or democracy, or oil or whatever – think how far he would go for food!

Such a pasture shortage would, however, have one benefit. It would reduce urban sprawl by making rural land prohibitively expensive.

“Enriching the Earth,” by Vaclav Smil, provided me some information for this column.

Rodney Quinn, a resident of Gorham, is an author and former secretary of state.