What is food synthesis in green plants

The nitrogen dilemma

By Peter Clausing

In 1910, BASF patented a chemical process for the synthesis of ammonia from nitrogen and hydrogen. According to Wikipedia, the process developed by the later Nobel Prize winners Fritz Haber and Carl Bosch represents the “most important industrial process for converting the unreactive nitrogen in the air into a usable nitrogen compound”. This is an energy-intensive process that requires temperatures of 500 degrees Celsius. The Haber-Bosch process had its first boom in the First World War, when large quantities of ammonia were required for the manufacture of ammunition and explosives. The namesake of the process were entirely in the German militarist tradition. Fritz Haber is known as the “father of the gas war” in World War I and the younger Carl Bosch was a “military economic leader” during the Nazi era, that is, a top functionary in the Nazi war economy. Similar to other occasions - think of the nuclear industry - new sales markets were sought after the end of the war. The era of synthetic fertilizers began. Today the myth is maintained that the nutrition of half the world's population depends on this fertilizer.

Energy is an important resource for human civilization, and nitrogen is an indispensable plant nutrient. But the synthetic fertilizer is similar to nuclear power - both are dispensable. And there is another parallel to atomic energy: Nitrogen has a similarly dramatic environmental impact, but it is far less present in the public consciousness. Nitrogen (and phosphate) are not as dangerous as fuel rods from nuclear power plants, but they are not stored temporarily or permanently, but escape into the environment on a large scale in a completely uncontrolled manner. The sources of pollution by nitrogen is not only synthetic fertilizer, but it is also the feces from animal production. In addition, there are industrial emissions and insufficiently treated wastewater. In countries with intensive agriculture, according to official estimates, on average only 20-30 percent of the nitrogen applied (and around 50 percent of the phosphorus) are used as plant nutrients. The rest ends up in the environment and causes nutrient overload (eutrophication) and acidification of ecosystems as well as adverse health effects. Laughing gas is released, which is around 300 times more harmful to the climate than carbon dioxide.

It took decades from the realization that the environment was polluted with excess nitrogen to the first tentative measures being taken. In 1996, a fertilizer ordinance was passed in Germany which, starting in 2010, prescribes a gradual reduction in excess quantities from 90 to 60 kilograms per hectare of agricultural land. In other words, although the annual amount of nitrogen surplus is to be reduced, water and soil are still polluted with reactive nitrogen. In July 2014, the Federal Environment Agency pointed out that, on the one hand, it had succeeded in significantly reducing the input of unused nutrients from "point sources" (insufficiently treated wastewater), but that "the inputs from diffuse sources [...] are still a largely unsolved problem ( put)". The annually registered nitrogen surplus in Germany was reduced from 130 to 101 kilograms per hectare between 1991 and 2012. The target of a reduction to 80 kilograms set by the federal government for 2010 was, however, clearly missed. In 2005, according to the Federal Environment Agency, around 550,000 tons of nitrogen were released into surface waters alone, 62 percent or almost two thirds of this was due to agriculture.

A major cause of nitrogen pollution in EU countries is the population's high consumption of animal protein. The annual per capita consumption of protein per year in Western Europe was 25 kilograms as early as 1960, well above the nutritionally recommended 18 kilograms and consisted of half of vegetable and animal protein. The increase to over 30 kilograms per capita by 2007 was solely due to an increase in animal protein. Further figures clarify the problem with regard to nitrogen pollution: In Europe, the efficiency of nitrogen fertilizers applied to grain is an unsatisfactory 30 to 60 percent, i.e. 40 to 70 percent are not used and pollute the environment. But if the conditions for grain are unsatisfactory, they are catastrophic for meat: Here the nitrogen efficiency - depending on the species - is between 2.5 and 20 percent.

The pollution of the environment by nitrogen is only one aspect, albeit a particularly important one. In addition, there is the energetic inefficiency of intensive agriculture, to which synthetic fertilizers make a significant contribution. Jodi Ziesemer, who carried out a corresponding study for the World Food Organization FAO in 2007, points out that around half of the energy that is directly consumed in this production model is used in the production of nitrogen fertilizers. This explains why almost all agricultural products, even under European conditions, have a significantly better energy balance when grown organically than under conventional conditions. For Great Britain, Ziesemer refers to data that show that in the case of many crops, organic farming achieves energy savings of around 30 percent, and in some cases significantly more. From an energetic point of view, the purpose of agriculture used to be, among other things, to transform solar energy into consumable energy. If you look at the entire current production process for the production of food, then four times more fossil energy is consumed here than subsequently end up on the plate in the form of calories. Both national food energy balances in Denmark and the USA and a Swedish study in which the energy expenditure of daily rations from supermarket purchases were analyzed come to around this value. When comparing agro-ecological small-scale agriculture with conventional cultivation, it can be assumed that there is a difference of up to a hundredfold in energy efficiency. Although this is an extreme value, it gives an idea of ​​the agro-ecological potential for energy savings.

Are we facing an unsolvable dilemma? Does a desirable higher energetic efficiency of agro-ecological cultivation collide with the inability of this cultivation system to feed the world population? Is Malthus still right after a 250 year delay? By the year 2050, the world population is expected to grow by a further two billion people to a good 9 billion (and then to stabilize). Against this background, the World Bank and the World Food Organization predict the need for a 70 percent increase in food production within the next 35 years. In an important EU policy advisory document, the European Nitrogen Assessment, it is pointed out that organic cultivation of grain would result in a 40 to 50 percent loss of yield. It seems that we have a choice between a global famine caused by insufficient yields and a global environmental catastrophe caused, among other things, by the annual input of millions of tons of nitrogen.

In fact, what is frightening is less the contradiction between world nutrition and environmental protection than the ignorance of existing alternatives. First of all, it is noticeable that the world population with the forecast figure of 9.2 billion people is expected to grow by 30 percent by 2050. The required increase in production should, however, be 70 percent. This is justified with changes in eating habits. This means increasing the consumption of animal products in countries like China. But actually the eating habits in Europe - apparently regarded as inevitable - should change. This applies not only to the consumption of meat and dairy products, but also to the fact that in the EU 20 to 30 percent of the food bought ends up in the trash. In addition to wasting what is produced, this is a burden on the environment and a waste of energy. Wouldn't it make more sense in Europe to compensate for the yield losses that agro-ecological cultivation may bring with it, but which are far less than is generally claimed, and to use the energetic and environmental advantages? in the European Nitrogen Assessment Possible “behavioral changes” of the consumers are mentioned in the introduction, but the future scenarios focus on technological developments - including genetic engineering and visions of agricultural robots. Fundamental social change or a politically controlled “agricultural turnaround” are not envisaged.

Instead of massively promoting agro-ecological cultivation systems, they are defamed against their better judgment as "agrarian romance of the middle class", which is allegedly associated with considerable drops in yield. The repeatedly rumored difference in yield of 40 to 50 percent for grain compared to conventional cultivation is in clear contradiction to the actual data situation. In long-term tests by the Rodale Institute in Pennsylvania, USA, identical yields were determined for corn and wheat for the agro-ecological and conventional cultivation methods. In a summarizing analysis for grain in industrialized countries, a research group from the University of Michigan (Catherine Badgley et al.), Who evaluated 69 comparative studies, came to a reduced yield of only 7.2 percent. This makes it clear that agro-ecological restructuring in Europe is blocked by a lack of coherence in agricultural policy and insufficient incentives in agricultural practice, as well as by inadequate research funding.
What are the causes of resistance to a tangible solution that takes time but is coherent in itself?

Perhaps the strategists of European agricultural policy are more far-sighted than assumed. A comprehensive conversion to agro-ecological cultivation systems would not simply mean the loss of sales markets for the agrochemical industry. A consistent development in this direction would be associated with a whole cascade of social changes. It would mean a massive loss of sales opportunities for agrochemical products. Strong resistance from industry is logical. In addition, if there were such an agricultural turnaround, the mining, chemical and energy union would probably also be on the plan in Germany (see the role of IG Metall in the current discussion on arms exports). An agro-ecological restructuring would also be linked to a far-reaching structural change in agriculture.This is countered by the persistence of the German Farmers' Association, the interest group for conventional agriculture with around 300,000 members, such a policy and the wishes of the Rural Agriculture Action Alliance, a network with around 5,000 members that is open to agroecology. Agro-ecological cultivation would be significantly more labor-intensive. Several hundred thousand new jobs would be created in agriculture. These additional jobs would more than compensate for the job loss in the agrochemical industry. In addition, a (justified) increase in the price of food is to be expected. However, cheap food is known to be an important means of calming down the population.
In a word, such an agricultural turnaround would be equivalent to a dramatic change in society as a whole. It is understandable that this is not wanted by the rulers.


Catherine Badgley et al. (2007): Renewable Agriculture and Food Systems 22: 86-108.

European Nitrogen Assessment (2011). Cambridge University Press. http://www.nine-esf.org/ENA-Book

Federal Environment Agency (2014): Nutrient inputs from agriculture and nitrogen surplus. http://www.umweltbundesamt.de/daten/land-forstwirtschaft/landwirtschaft/naehrstoffeintraege-aus-der-landwirtschaft.

Jodi Ziesemer: Energy use in organic food systems. Rome, FAO, 2007, http://www.fbae.org/2009/FBAE/website/images/pdf/imporatant-publication/fao-organic-report.pdf

Further sources: here

Published in Lunapark21, issue 27, autumn 2014

Article of November 19, 2014