Crop rotation was very effective when a large percentage of the population lived on the land, but becomes much less effective when the nutrients are all carted off to the big cities. The author also fails to be aware that there are other essential elements such as phosphorus and potassium. Without these, plant growth is poor, even with the addition of large amounts of nitrogen. The world's supply of these raw materials for the production of food will one day run out and so the population will starve. It won't be in our lifetime, but it will surely happen and the present rate of population growth, it may be sooner, rather than later. Those remaining will discover the true meaning of the term "Might is right."

David

The reality is that beggars cannot be choosers and given Australia's
monthly current account deficit, we need to pay our bills somehow.

Mining and farming are basically what we have to do it with, few
other Australian industries are globally competitive.

BTW we are not about to run out of gas. We've only just realised
how much we have, both on the North West shelf and CSG reserves.

I remind everyone that in the 60s, it was thought that Australia
hardly had any iron ore, until Hancock discovered whole mountain
chains made of the stuff.

China's chief food problem won't be fertiliser. It is currently twofold. The reducing area of land available for farming and the increasing depth's required to reach underground water. Surface water is far to poluted and scare in farming areas already.

They'll run out of water before they run out of fertiliser.

I don't think we need worry two much about the costs of or depletion of fossil fuels. With the huge developments in generating solar power and current battery technology in the past year or so within five years every truck, bus, train, ship, car, small boat, house, office block, shop and factory will produce and store sufficient or excessive power cheaply enough for no one to need bother with fossil fuels of anytype, tough for all those involved in their production but they'll adapt. Whatever happened to the steam engine industry and it's ancillaries?

Food propduction techniques will evolve quickly enough to avert catastrophy.

Why don't the merchants of fear realise the damage they are doing to our children and that everyone else realise there is no such thing as safety and security.
The universe could swat us all like a fly in an instant and all the fake social or physical edifices we've built are absolutely useless and pointless.

Thanks for some perceptive comments, guys.

Couple of points. Yes, the world actually passed 'peak phosphorus' in 1988 and this is, potentially, a far more serious problem even than nitrogen. I just didn't want to scare anyone.

For those who imagine our resources are ample, 400 years supply of a given resource for Australia is only 7 years supply for China or India. We cannot comfort ourselves by clinging to a view that we are not connected to the rest of the world.

Third, yes, there are lots of ways we can make nitrogen fertilisers or recycle nutrients. They are just far more expensive, inefficient or less agriculturally productive than the gas route. So by becoming aware of the potential for gas to run out, we start to work on making them more efficient. I wrote the article because, while one hears endless debate about peak oil, one almost never hears about peak gas, which is just as worthy of being treated seriously by thoughtful people.

Julian, the problem is that the thoughtful people are not numbered amongst governments or their advisers. Their thoughts are only aimed at winning the next election.

David

Modern farmers can and should know precisely how much of their chemical resource they lose, every time they send product off the property.
A dairy farmer for instance, buys fertiliser in, has his cattle convert the fertiliser into milk, and lives on the price difference.
We as a nation desperately need to adopt the same philosophy. Currently, almost everything we produce either goes overseas, or in the sea.
About the only biomass we don't dump in the ocean are our own rotting corpses, which we either burn, or lock up in cemeteries, which grow nothing more than a pretty patch of grass.