The Nitrogen Cycle

The Earth’s Biosphere
Professor Vaclav Smil, in his July, 1997 Scientific American article “Global Population and the Nitrogen Cycle”, describes the remarkable relationship between the rise in human population over the past century and the availability of synthetic nitrogen fertilizers.

These fertilizers where made possible by the Haber-Bosch process developed in 1899.

Naturally-produced fertilizers can provide approximately 200 kg. of nitrogen per hectare annually; this allows for the production of between 200 and 250 kg. of plant proteins. This places a theoretical limit on the number of people that each hectare of land could sustain. Under ideal conditions this would amount to around 15 people per hectare; in practice, the historical limit has been about 5 people per hectare.

The use of synthetic nitrogen fertilizer has allowed these limits to be broken. At current levels, world-wide, these fertilizers account for 40 percent of all nitrogen taken up by cultivated crops. And since these crops contribute 75 percent of all nitrogen in consumed proteins, this means that one third (i.e., 75% of 40%) of humanity’s diet depends on synthetically produced nitrogen.

Smil puts it into these very concrete terms:

“… at least two billion people are alive because the proteins in their bodies are built with nitrogen that came from a factory using [the Haber-Bosch] process.”

He has a new book, The Earth’s Biosphere: Evolution, Dynamics, and Change that I would highly recommend. It’s an interdisciplinary survey of the biosphere and the systems and processes that provide for its self-regulation. It touches on a wide variety of subjects including chemistry, biology, genetics, geology and astronomy; and while it can be a bit jargon-heavy at times, anyone with a reasonable exposure to these areas would not have any trouble following the material. I came away from the book with an even greater appreciation for the workings of our planet than I already had.

» Posted: Sunday, February 15, 2004 | Comments (1) | Permanent Link


I asked my son to reply to this young man. My son is the manager of an oranigc fertilizer company in the Idaho Falls, Idaho area. He has a Bachelor of Science degree from BYU, ID. Their primary customers are potato growers which is increasing every year because of their profit margin is increasing.First thing I would say is that this young man sounds an awful lot like me when I was in college. I wasn’t convinced of oranigcs either. In fact I wrote several papers against oranigc farming. Most of the information I used for my papers were taken from very biased sources. After being involved with an oranigc fertilizer company; in Idaho I might add; you could say that I have seen the light. The first argument I would make is that the oranigcs game has become amazingly efficient also. The days of just throwing several inches of manure on the ground and letting the crop grow are long over. In fact I don’t know any oranigc farmer in the state of Idaho that uses straight manure. Now compost that’s a different story.The next argument I would make is that potatoes need 400 lbs of nitrogen per acre. Wow! That’s a lot of nitrogen, especially in the form of a petroleum based chemical. Although it doesn’t surprise me that some farmers apply that much. After years and years of using petroleum based chemical fertilizer they have pretty much destroyed most of the oranigc matter in their soil along with all the beneficial microbes and other trace element that the plants need.Bottom line is this. First, most oranigc farmers don’t use raw manure anymore. They use composted manure. Big difference between the two. The compost process allows the manure to be broken down into pure oranigc matter. Which has a much higher nutrient value than manure. A good compost will have about 22-27 lbs of nitrogen per ton. This is a big difference from the 10 lbs per ton from the raw manure. With compost you’re not only getting nitrogen you are also getting about 35 lbs. of phosphorous per ton and 67 lbs per ton of potassium. Not to mention many other trace elements such as sulfur, magnesium, calcium, iron, manganese, copper, zinc, boron, and humic acid. All of which are extremely important to the plant. Most conventional farmers spend so much money on nitrogen, phosphorous, and potassium (NPK) that they don’t have enough left over for the trace elements. Now on oranigc potatoes we put down about 15 tons per acre. Which is about 1/2 inch thick. Also, we don’t rely on compost as the only source of Nitrogen. Throughout the growing season we add several different types of oranigcally approved liquid fertilizers to potatoes so that we don’t have to rely on compost as our only source of nutrients. We also get a residual affect from compost. Because it is a natural form of oranigc matter it stays in the soil which also helps for the next years crop .that is until the next farmer comes along and decides to put a petroleum based chemical fertilizer on the field, in which case it would destroy most of the oranigc matter and beneficial microbes.Besides compost being a good nutrient source it also has other benefits. Such as water holding capacity. Farmers have found that they use less water on their oranigc crops than they do on their conventional crops. On average about 25% less, and as much as 35% less. Anyway I could continue to go on and on about the benefits and misconceptions of oranigc farming, but I hope this shows that if you want to know the truth about oranigcs talk to someone who knows about oranigcs.Oh by the way another misconception is that oranigc food costs more to produce. Not true. We can grow a crop of oranigc potatoes for about the same cost as a conventional crop, sometimes even less. This gives an oranigc farmer a much higher profit margin because oranigc food sells for more. It sells for more because of supply and demand and thats a whole other debate.

» Posted by Messi on December 26, 2012 09:19 AM