<p>There are a number of factors that went/are going into the population explosion, food is only one vaccination and antibiotics are a big factor as well.  within food fertilizer is again only one of many factors. Better crop strains, mechanized and better farming techniques, soil science, pesticides, refrigeration, and a dozen other factors contributed.  Keep in mind artificial fertilizers get less important as you go back in time as well so calling it the detonator is incorrect and misleading. </p>

<p>Now when considering crop rotation, crop rotation has pros and cons, there are several nutrients plants need and rotation only helps with some of them, and it relies on having compatible crops to rotate which not every crop or environment has.</p>

<p>Keep in mind the piece wikipedia is quoting is not a peer reviewed paper but an <a href="http://vaclavsmil.com/wp-content/uploads/docs/smil-article-1999-nature7.pdf" rel="nofollow noreferrer">essay</a> in nature, which explains it is referring to several modern countries that fertilize almost exclusively with artificial fertilizers. It is not claiming they cannot use other fertilizers.</p>

CC BY-SA 4.0
2018-11-14T21:23:45.403Z
Add to the last paragraph that time scales for the Wikipedia article and the Bio-Swiss reference are different. A 20% difference using today's technology versus a x4 increase from standards used over a century ago are two different metrics entirely.
Jeffrey J Weimer
CC BY-SA 3.0
2018-04-12T23:07:18.720Z
2018-04-13T13:23:04.663Z
2018-04-13T13:23:04.663Z
John
<p>There are several aspects to be considered in this apparent difference.</p>

<p>First, your quote from Wikipedia describes the change in productivity but does not account for other factors that have lead to productivity increase such as changed farming practices (larger, more sophisticated farm equipment, improved use of weather and soil data, etc.) changes to crop species and cultivars - especially the increase in use of hybrids, and increased irrigation. Thus, the contribution of nitrogen fertilizers is only one factor, although an important one.</p>

<p>Secondly, you can compensate for the lack of chemical nitrogen fertilizer through a number of methods, but that doesn't negate the changes due to the widespread adoption of nitrogen fertilizers. You can use organic fertilizers to increase production but there may be limits on the ability to do so on the scale of conventional agriculture. You may be able to use more labor-intensive techniques on a small scale that could not be adopted on the scale of modern agriculture.</p>

<p>Additionally there are cost considerations. It may not always be financially feasible to increase productivity through organic farming methods. Or at least society may not be willing to pay the price</p>

CC BY-SA 3.0
2018-04-13T00:52:55.263Z
2018-04-13T00:52:55.263Z
haresfur
<p>Im a bit confused on how crucial Nitrogen fixation with the Haber-Bosch process really was. On the <a href="https://en.m.wikipedia.org/wiki/Haber_process" rel="nofollow noreferrer">Wikipedia page of the Haber-Bosch process</a> it says:</p>
<blockquote>
<p>In combination with pesticides, these fertilizers have quadrupled the
productivity of agricultural land.</p>
<p>With average crop yields remaining at the 1900 level the crop harvest
in the year 2000 would have required nearly four times more land and
the cultivated area would have claimed nearly half of all ice-free
continents, rather than under 15% of the total land area that is
required today.</p>
<p>Due to its dramatic impact on the human ability to grow food, the
Haber process served as the &quot;detonator of the population explosion&quot;,
enabling the global population to increase from 1.6 billion in 1900 to
today's 7 billion.</p>
</blockquote>
<p>However I have read that the products <a href="https://www.bio-suisse.ch/en/home.php" rel="nofollow noreferrer">labelled &quot;Bio&quot; in the stores in Switzerland that don't use nitrogen fertilizers</a> have only about 20% lower yields, which is a dramatically different number than what the Wikipedia page on the Haber-Bosch process claims (quadrupling of productivity).</p>
<p>What am I missing? Did the nitrogen cycle change so much so that we don't need nitrogen fertilizer nowadays? Did new technology enable us to get similar yields without nitrogen fertilization? What explains these numbers? Was crop rotation an unknown concept in the 1900’s?</p>

CC BY-SA 3.0
2017-08-11T08:55:14.277Z
The first sentences states "In combination with pesticides, ...". Therefore, I would assume that a combination of pesticides, fertilizers (also phosphorus!), and new plant species yielded this 4x yield.
daniel.heydebreck
CC BY-SA 3.0
2017-08-11T08:59:44.270Z
In addition (I am not an expert on agriculture -- so this can be wrong!): (a) I would assume that you can reduce the need for fertilizers considerably by crop rotation and planting intermediate nitrogen-fixating crops. (b) For example in northwestern Germany, we have a lot of industrial-like animal husbandry. A lot of manure is available and put onto fields. This leads to a considerable excess of nitrogen in the soils and to threshold-exceeding nitrate loads in some ground water bodies. What I mean: in some regions there is not need for industrial N-fertilizers in the moment.
daniel.heydebreck
CC BY-SA 3.0
2017-08-11T09:04:04.120Z
@daniel.neumann On the bio website that I linked it does say that they use crop rotation. Is this not possible in some (or many) parts of the world, making them have to use nitrogen fertilizers?
macco
CC BY-SA 3.0
2017-08-11T11:18:51.073Z
The aim of crop rotation is also to reduce the vulnerability to insect pests and to have plants with different root depths and nutrient needs. Nitrogen fixating plants can also be planted in the monoculture setup: spring+summer grows the default crop (soy etc.) and in autumn the nitrogen fixers. But yes: If you neither have manure nor nitrogen fixers (e.g. due to too less water), you probably need nitrogen fertilizers.
daniel.heydebreck
CC BY-SA 3.0
2017-08-12T14:39:44.770Z
@daniel.neumann Just pointing out that [soy is a nitrogen fixer](http://en.wikipedia.org/wiki/soybean#Nitrogen-fixing%20ability).
Spencer
CC BY-SA 4.0
2020-05-09T07:16:27.003Z
@RodrigodeAzevedo Which point do you mean? Item (b) of my second comment? I agree with you. However, the feed often is not grown where the livestock ist fed and the manure is produced. That was the background for my comment. I should have clarified it. But, right: without application synthetic fertilizer at another location, we couldn't "produce" that much manure here.
daniel.heydebreck
CC BY-SA 4.0
2020-05-09T07:40:47.980Z
@daniel.neumann Thank you for the clarification. In essence, synthetic fertilizer is being applied *indirectly* in the form of manure.
Rodrigo de Azevedo
<agriculture><nitrogen>
Did the Haber-Bosch process enable the population explosion?
macco
# Did the Haber-Bosch process enable the population explosion?

(Asked by: username_0 on 2017-08-10)

Im a bit confused on how crucial Nitrogen fixation with the Haber-Bosch process really was. On the [Wikipedia page of the Haber-Bosch process](https://en.m.wikipedia.org/wiki/Haber_process) it says:

> In combination with pesticides, these fertilizers have quadrupled the
> productivity of agricultural land.
>
> With average crop yields remaining at the 1900 level the crop harvest
> in the year 2000 would have required nearly four times more land and
> the cultivated area would have claimed nearly half of all ice-free
> continents, rather than under 15% of the total land area that is
> required today.
>
> Due to its dramatic impact on the human ability to grow food, the
> Haber process served as the "detonator of the population explosion",
> enabling the global population to increase from 1.6 billion in 1900 to
> today's 7 billion.

However I have read that the products [labelled "Bio" in the stores in Switzerland that don't use nitrogen fertilizers](https://www.bio-suisse.ch/en/home.php) have only about 20% lower yields, which is a dramatically different number than what the Wikipedia page on the Haber-Bosch process claims (quadrupling of productivity).

What am I missing? Did the nitrogen cycle change so much so that we don't need nitrogen fertilizer nowadays? Did new technology enable us to get similar yields without nitrogen fertilization? What explains these numbers? Was crop rotation an unknown concept in the 1900’s?

**Tags:** agriculture, nitrogen

> **Comments:**
> **username_1**: The first sentences states "In combination with pesticides, ...". Therefore, I would assume that a combination of pesticides, fertilizers (also phosphorus!), and new plant species yielded this 4x yield.  
> **username_1**: In addition (I am not an expert on agriculture -- so this can be wrong!): (a) I would assume that you can reduce the need for fertilizers considerably by crop rotation and planting intermediate nitrogen-fixating crops. (b) For example in northwestern Germany, we have a lot of industrial-like animal husbandry. A lot of manure is available and put onto fields. This leads to a considerable excess of nitrogen in the soils and to threshold-exceeding nitrate loads in some ground water bodies. What I mean: in some regions there is not need for industrial N-fertilizers in the moment.  
> **username_0**: @daniel.neumann On the bio website that I linked it does say that they use crop rotation. Is this not possible in some (or many) parts of the world, making them have to use nitrogen fertilizers?  
> **username_1**: The aim of crop rotation is also to reduce the vulnerability to insect pests and to have plants with different root depths and nutrient needs. Nitrogen fixating plants can also be planted in the monoculture setup: spring+summer grows the default crop (soy etc.) and in autumn the nitrogen fixers. But yes: If you neither have manure nor nitrogen fixers (e.g. due to too less water), you probably need nitrogen fertilizers.  
> **username_2**: @daniel.neumann Just pointing out that [soy is a nitrogen fixer](http://en.wikipedia.org/wiki/soybean#Nitrogen-fixing%20ability).  
> **username_1**: @username_3 Which point do you mean? Item (b) of my second comment? I agree with you. However, the feed often is not grown where the livestock ist fed and the manure is produced. That was the background for my comment. I should have clarified it. But, right: without application synthetic fertilizer at another location, we couldn't "produce" that much manure here.  
> **username_3**: @daniel.neumann Thank you for the clarification. In essence, synthetic fertilizer is being applied *indirectly* in the form of manure.  

---

## 2 answers

### Answer by username_4 on 2018-04-12. Score: 4

There are a number of factors that went/are going into the population explosion, food is only one vaccination and antibiotics are a big factor as well. within food fertilizer is again only one of many factors. Better crop strains, mechanized and better farming techniques, soil science, pesticides, refrigeration, and a dozen other factors contributed. Keep in mind artificial fertilizers get less important as you go back in time as well so calling it the detonator is incorrect and misleading.

Now when considering crop rotation, crop rotation has pros and cons, there are several nutrients plants need and rotation only helps with some of them, and it relies on having compatible crops to rotate which not every crop or environment has.

Keep in mind the piece wikipedia is quoting is not a peer reviewed paper but an [essay](http://vaclavsmil.com/wp-content/uploads/docs/smil-article-1999-nature7.pdf) in nature, which explains it is referring to several modern countries that fertilize almost exclusively with artificial fertilizers. It is not claiming they cannot use other fertilizers.

> **Comments:**
> **username_5**: Add to the last paragraph that time scales for the Wikipedia article and the Bio-Swiss reference are different. A 20% difference using today's technology versus a x4 increase from standards used over a century ago are two different metrics entirely.  

---

### Answer by username_6 on 2018-04-13. Score: 2

There are several aspects to be considered in this apparent difference.

First, your quote from Wikipedia describes the change in productivity but does not account for other factors that have lead to productivity increase such as changed farming practices (larger, more sophisticated farm equipment, improved use of weather and soil data, etc.) changes to crop species and cultivars - especially the increase in use of hybrids, and increased irrigation. Thus, the contribution of nitrogen fertilizers is only one factor, although an important one.

Secondly, you can compensate for the lack of chemical nitrogen fertilizer through a number of methods, but that doesn't negate the changes due to the widespread adoption of nitrogen fertilizers. You can use organic fertilizers to increase production but there may be limits on the ability to do so on the scale of conventional agriculture. You may be able to use more labor-intensive techniques on a small scale that could not be adopted on the scale of modern agriculture.

Additionally there are cost considerations. It may not always be financially feasible to increase productivity through organic farming methods. Or at least society may not be willing to pay the price


---

