"In the United Kingdom more than half of all nitrogen fertilizer has been applied to grasslands. A Royal Society study found that in the late 1970s average applications on pastures surpassed the inputs to arable land (172 vs. 135 kg N/ha), and that synthetic compounds accounted for 57-63% of all inputs. The overall use of fertilizer nitrogen in the United Kingdom rose by almost 50% between the late 1970s and the mid 1980s, but it declined afterwards, and its average during the late 1990s has been only about 20% higher than a generation earlier, which means that the synthetic fertilizers supply between 65 and 70% of all nitrogen inputs. But high-yielding winter wheat -- the 1998 mean was 7.97 t/ha -- still receives more than 180 kg N/ha, double the amount applied in 1970 when the yield was around 4 t/ha, and the secular correlation between the rising applications of inorganic nitrogen and rising harvests is obvious (fig. 7.8)."

Now imagine 300 more pages of text just like that, and you get the idea. There is no *story* here, just data. It's a shame, because there is definitely a story to be told.

The material on the Haber process itself is better, but not great. In particular, the author can't seem to choose the level of the audience: descriptions of chemistry alternate between being too simplistic and assuming too much. Details essential to understanding often seemed to be missing, while details of no apparent relevance are in abundance. I don't really care whether the process takes place under 137 vs. 152 atmospheres; but I do care *why* the pressure is so critical, which is never explained.

I really wanted to like this book more than I did. There *is* plenty of good material here, but you have to sort through a lot of empty statistics to get it, and the omission of key pieces of scientific explanation makes for a painfully frustrating read.

7 of 7 found the following review helpful:


Nitrogen in agriculture: from composting and guano to Haber-Bosch and artificial fertilizers  Mar 25, 2007 By lector avidus
First of all, this is not a book that most people would take to the beach to read, but rather a fairly scientific book on the use of nitrogen in agriculture, as befits a publication of MIT Press.

Smil initially set out to write a biography of Fritz Haber, but found that Haber's contribution to agriculture was so much more complicated than he could fit into a biography. Instead, he wrote a history of nitrogen supplements in agriculture. The amount of nitrogen is by far the main determinant of crop yield; within common sense limits, a crop's yield is more or less linearly dependent on how much nitrogen a farmer spreads on his fields. In the 1910s, Fritz Haber and Bosch, devised a way to extract nitrogen from the air; until then farmers had been dependent on compost and the shipments of guano (bird dung) from South America to get more nitrogen onto their fields. The results include a huge increase in crop yields, a huge decrease in the percentage of the population that must toil the fields, a huge increase in literacy and much more.

Smil's book is quite interesting to anyone interested by science; if you have a teen that you are trying to interest in science, this is a book you could send his way. If you're averse to the occasional number, equation, graph, or scientific nomenclature, you're best off avoiding this book. These caveats stipulated, I highly recommend this book.

7 of 7 found the following review helpful:


Nitrogen in Agriculture -- The Haber-Bosch Process  Jun 18, 2001 By Scott Holub
This is a great book for any one interested in the way the Haber-Bosch process of making Nitrogen fertilizer changed the world. Enriching the Earth provides in depth information on the history that led up to the discovery of the process of using N2 and H2 to make NH3. It also contains up to date information on the effects that all of this new nitrogen has on the earth.

The book can get a little technical at times, with chemical formulas and schematics of the instruments. While I found this information useful, some people might find it overwhelming. If you skip over the techincal parts, the book is very well written for the average person.

These little known scientists really changed the world as we know it. When you think about it, what has Einstein done for you lately? These guys put food on the table.


A superb account of the synthesis of ammonia and the role of nitrogen in agriculture  Mar 19, 2010 By Paul Moreno
No other technology of the 20th Century had more effect on raising the standard of living of the people of the world than the synthesis of ammonia which allowed the population to be several times higher than it otherwise would have been and also greatly reduced hunger and malnutrition in most parts of the world.

The book begins with the early science of chemistry and the development of a basic understanding of crop nutrition and the role of nitrogen in the early 1800's. After nitrogen's vital role was established a fertilizer industry based on guano and later Chilean nitrates, but supplies were being depleted. Synthetic nitrogen fertilizers were developed in the late 1800's, but the processes were very costly.

Fritz Haber built on the works of other chemists and eventually determined conditions (temperature, pressure, catalyst) whereby ammonia could be synthesized from hydrogen and nitrogen with a satisfactory yield. The process required high pressures and elevated temperatures which had never been used on an industrial scale before. It was Carl Bosch, a chemical engineer, who believed the process could be commercialized, and proceeded to develop the field of high pressure chemistry.

This is an excellent semi-technical book because: 1) subject matter importance, 2) overall it was interesting because it is part historical, part biographical, part popular science, 3) it is exceptionally well researched and documented. However, while it was very easy for a chemical engineer like myself to read, I am not sure it would be appreciated by someone without a similar background, although the sections pertaining to the use of nitrogen fertilizers may be of interest to those involved with agriculture. Also, it is highly recommended to economists involved with the impacts of technology on the economy.