Tag Archives: food

Non-toxic yesterday, but toxic today

In the 1940s a group of competent toxicologists led by William B. Deichmann conducted a number of thorough studies using state-of-the-art methods to conclude that the active ingredient dichloro-diphenyl-trichloroethane, or DDT, could be safely released to the environment for its use as insecticide. DDT was one of the first wide spread synthetic pesticides, and its widespread use led to resistance in many insect species.

ddt-good-for-me  ddt-recommended ddt-uses

As can be seen in the pictures, DDT was promoted to be used as insect repellent directly on human skin, to treat food products, or to impregnate the wall paper of your children’s room, so they won’t be bothered by mosquitoes. Tender images, such as a mother feeding a baby were used in commercial campaigns to basically sell poison. (*)

In the early 1970s, a scientific article authored by Deichmann (1972) himself and other studies provided enough evidence for the US Environmental Protection Agency to finally forbid the use of DDT as it became known to be toxic to humans, persistent in the environment, travel long distances in the upper atmosphere, and accumulate in fatty tissues of living organisms.


Rising evidence

What did actually happen between the 1940s and the 1970s? Why was DDT first considered innocuous or degradable and 30 years later banned and labelled as poisonous for humans, wildlife and the environment?There are several possible answers to these questions.

In the fist place, the ecotoxicity of certain chemicals when applied in small doses may only appear through cumulative effects (cf. http://www.efsa.europa.eu/fr/node/872721). Time is needed for problems to arise, or to become evident.

Second, and most importantly, the capacity of science to detect the adverse effects of a certain molecule released to the environment can progress substantially in 30 years.Problems that were overlooked or remained undetected in the past could be later on well understood and documented. (And the amount of scientific evidence that needs to be accumulated to be able to bend the arm of the chemical industry in court cases is not a minor detail).

The most skeptical opinions, in the third place, would argue that DDT was banned once the patent for exclusive production expired, and /or when the industry was ready to release a new product on the market. But these are just speculations.

Take home!

What’s important to take home is that examples such as this one should teach us about the long-term risk (uncertainty) associated with the widespread release of toxins into the environment, either as synthetic molecules or through toxin-producing plants (e.g., Cheeke et al., 2012). Alarming ideas such as the commercial release of genetically engineered microorganisms for soil amendment have been underway for a while (e.g. Viebahn et al., 2009), with unknown consequences for soils and the environment.

When it comes to releasing new technologies for food and agricultural production, I’d say it makes sense to follow precautionary principles. Releasing toxins into the environment: another case of organised irresponsibility…


(*) I believe that, nowadays, the baby in the early campaigns of DDT has been replaced by the term ‘sustainability’, which is also used in commercials and websites that advertise poison or toxin-producing plants.


Cheeke, T.E., Todd N. Rosenstiel, and Mitchell B. Cruzan. 2012. Evidence of reduced arbuscular mycorrhizal fungal colonization in multiple lines of Bt maize. American Journal of Botany 99, 700-707. DOI: 10.3732/ajb.1100529

Deichman, W.B., 1972. The debate on DDT. Arch. Toxikol. 29 (Springer), 1 – 27.

Viebahn, M., Smit, E., Glandorf, D.C.M., Wernars, K., Bakker, P.A.H.M., 2009. Effect of genetically modified bacteria on ecosystems and their potential benefits for bioremediation and biocontrol of plant diseases – a review. E. Lichtfouse (ed.) Sustainable Agriculture Reviews 2, Springer, p.45. doi 10.1007/978-90-481-2716-0_4.

Food produced vs. food delivered

A relatively small proportion of the food produced in the high-yielding regions of the world is actually delivered to the food system. Not just because of waste, which accounts for anything between 30 and 50% from post-harvest and manufacturing through to trade and consumption. Here, ‘delivering’ means how much food enters the food system in the form of edible items (even before it is wasted). A global study by Cassidy et al. (2013) calculated this proportion using energy units.

They expressed the productivity of all the crops in calories per ha per year (to be able to compare apples and pears) and mapped them per region. They assumed that an average person requires 2700 Kcal per year. With these two pieces of information they calculated the number of people that could the fed per ha of agricultural land on the basis of its current productivity. Note that 2700 Kcal is greater than the actual human needs, which fluctuate according to physical constitution between 1800 and 2100 Kcal per person per year. By considering 2700 Kcal they are already assuming a certain level of inherent value chain inefficiency, which gives more conservative estimates.

Potential vs. actual delivery

The map they developed shows that the most productive areas of the world can potentially feed 8 to 10 people per ha on the basis of current productivity, while the least productive regions can feed barely 3 to 4. But then they produced another map, that estimates how many people are effectively fed per ha of land. They developed this new map by computing the fraction of the total energy contained in a crop that is delivered to the food system in the form of edible energy.

For example, in the case of maize (or corn), only ca. 25% of the energy contained in the crop is delivered as edible energy, be it in the form of maize grain, meal or flour, or transformed into meat, milk, fructose, bier or candies, etc. This is because maize is used as raw material by different non-food industries, such as paint additives, plastics or biofuels. But also, because a large proportion of the harvest is used to feed livestock, which is inherently inefficient, as we all know.

Maize represents perhaps the most extreme case. But when we consider all cereals together (maize, wheat, rice, barley, oats, rye, sorghum, millet, etc.) yet 46% is used directly as food (raw or processed), 34% to fed livestock, and 20% used by the non-food industry.

Source: ES Cassidy, PC West, JS Gerber, JA Foley, 2013. Redefining Agricultural Yields: From Tonnes to People Nourished per Hectare. Environmental Research Letters 8 (3), 8
Source: ES Cassidy, PC West, JS Gerber, JA Foley, 2013. Redefining Agricultural Yields: From Tonnes to People Nourished per Hectare. Environmental Research Letters 8 (click to enlarge)

Based on this information for the most important crops globally (not just cereals), Cassidy et al. built the above map, that shows the fraction of the total agricultural production delivered to the food system. In the most productive areas of the world, barely 20 to 30% of the food produced is delivered to the food system. In areas dominated by smallholder farming 80 to 100% of the food produced is delivered – i.e. consumed at home or traded locally. This does not mean though that food systems are necessarily more efficient, as post harvest losses can still be high in many of these regions.

These are – again – global estimates, based on a number of assumptions, and they may therefore be questioned. Yet they contribute further evidence to understand why increasing agricultural production in developed countries will continue to have a limited impact on achieving global food security (see also this previous post). Most of the non- or hardly renewable resources such as fossil fuels, rock phosphate, soils or (fossil) water are used in these regions to produce food that will never reach a human stomach.


Who’s producing our food?

There is quite some noise around the global figures on food production and consumption. The reality is that most of such figures are estimates, and estimates always rest on assumptions. For example, a question that always puzzles me is: what is the proportion of the food we consume that is produced by smallholder family farmers? A somewhat classical estimate points to 70%, as shown in the figure below, developed by the ECT group in 2009:

Peasants foodClick to enlarge

FAO’s State of Food and Agriculture 2014 Report (SOFA 2014) confirms, based on an analysis of 30 countries, that family farmers produce 80% of the world’s food. It is also often stated that this production takes place in only 20% of the agricultural land, and generally in less productive, marginal environments. Is this all true? Because if it is, then the implication is that smallholder family farming is highly efficient, producing most of the food humans eat in barely 20% of the surface, while other forms of farming use 80% of the land to produce the rest. Can we find enough evidence to back all this up?

(Just in case: I’m not questioning the importance of smallholder family farming in terms of global food security. I’m convinced that the only way to achieve food security is through increasing the productivity, sustainability and economic viability of smallholder farms. I’m aware that hunger is not a problem of production but of poverty and inequality, and that only 20% of the hungry live in cities.)

A smallholder farm is most likely a family farm (the opposite is not true)

According to IFAD, there are 500,000,000 farms in the world that are smaller than 2 ha. Unless this figure includes also intensive glasshouse production and/or irrigated orchards with high value crops, we could quite safely assume that most of these farms are smallholders, and that most of them are family farms. In China, for example, the average area of a family farm is 0.3 ha. In the East African highlands, where I worked for a number of years, an average rural household farms about one acre (or 0.42 ha) of land.

Colleagues at FAO are currently making a very serious attempt to quantify how many family farms are there, how much land they use, and how much they produce, based on the analysis of census data from 105 countries (Benjamin Graub and Barbara Herren, pers. Comm.). They estimated that family farms represent 98% of all farms in the world, and that they work on 53% of the agricultural land. They obviously produce most of the food in the world…

But this figure includes ‘family’ farms in places like the US or Europe, as defined by their respective survey authorities. The US census of 2007, for example, considers that 88% of their farms are family farms (i.e., those that are owned by the main operator). A value of 97% is estimated for Europe. The proportion of the total agricultural land held by family farms in these two regions is estimated at 68 and 69%, respectively. In South America, the proportion of family farms was estimated at 88%, but they hold only 18% of the agricultural land. The rest of the land is held by other actors of the agribusiness sector.

Confusion thus arises around the definitions of family and smallholder farms. These terms should not be used interchangeably. Each county has its own definition for these terms and this makes global calculations a hard task. The FAO, in the International Year of Family Farming (2014), defined family farming as:

“a means of organizing agricultural, forestry, fisheries, pastoral and aquaculture production which is managed and operated by a family and predominantly reliant on family labour, including both women’s and men’s. The family and the farm are linked, co-evolve and combine economic, environmental, social and cultural functions.”

Does size matter?

A cut-off value of <2 ha has been often used to define smallholder farms in global studies by e.g. the World Bank in its Rural Development Strategy (2003). According to IFAD, these farms support about 2 billion people. But individual countries have proposed variable cut-off values in their surveys. For example: Ecuador, <66ha; Nicaragua, < 50ha; Peru, < 50ha; Guatemala, < 45ha; Haiti, < 10ha; Vanuatu, < 5ha; Sub-Saharan Africa, < 10ha. The latter is also a commonly used threshold.

Graub and Herren (pers. Comm.) further calculated that if we take the example of Ireland, where 99% of the farms are considered to be family farms, and use a cut-off value of 10 ha, then only 18% of the farms would classify as such (farming on only 3.9% of the area). The family livestock farmers we work with in Uruguay, for instance, own an average of 80 ha of natural grassland per household, while those with whom we work in eastern Amazonia own up to 100 ha of land (including crops, pasture and forest).


Visiting  a ‘ smallholder’ family farmer in Uruguay

Perhaps the most telling part of FAO’s definition of farming families is then that they co-evolve with the land, combining economic, environmental, social and cultural functions. Size does matter, but not much. Alternatively, the MERCOSUR countries (Argentina, Brazil, Paraguay and Uruguay) use a multiple criteria definition of family farming (REAF Mercosur).

The High Level Panel of Experts on World Food Security (HLPE) defined family farming as:

“practised by families (including one or more households) using only or mostly family labour and deriving from that work a large but variable share of their income, in kind or in cash. Agriculture includes crop raising, animal husbandry, forestry and artisanal fisheries. The holdings are run by family groups, a large proportion of which are headed by women, and women play important roles in production, processing and marketing activities.” (HLPE, 2013, p. 10)

You are not the only one…

If you felt overwhelmed by the lack of certainty around global food production and consumption, and thought that you were just poorly informed, I hope these lines made you realize that you’re not alone! Such global estimates are uncertain even for specialists, due to the various reasons explained above. It was not my primary intention to come up with clear-cut figures. All I wanted to show here is that smallholder family farms are sort of ‘moving targets’, and that there is much that we still don’t know about them.

Moreover, in calculating global food balances a further distinction should be made between food production and food consumption. In areas dominated by smallholder family farms often most of the production is consumed at home and/or locally. I’ll come back to this in a next post. Yet, how many smallholder family farms are there, and how much food they contribute, remains elusive.

What we do know is that about 50% of the malnourished people on the planet belongs to smallholder farming households, another 20% to landless rural households, and 10% are pastoralists, fisher folks or forest users. About 580 million of them live in the Asia & Pacific region, 240 million in Sub-Saharan Africa, 50 million in Latin America and the Caribbean and about 40 million in the Near East and North Africa (Oxfam, Growing a better future, London, 2011). Any doubt on which our primary targets to achieve global food security should be?

OK, at least we know that.

More than just higher yields

(a commentary on a WLE blog post by Deborah Bossio, CIAT)

Can poor farmers afford to invest in restoring degraded soils?

This is a rhetorical question. When posed in this way, the answer should be a big NO.

The state of urgency in which poor smallholders live in many parts of rural Africa prevents investments in anything that will not yield immediate benefits. It prevents investments, full stop, especially where land tenure is not secured.

When farmers can make an investment, they prioritise the education of their children as a long-term strategy to move away from agriculture. Most smallholders in rural Africa are not farming by choice, and many of them considered themselves to be ‘unemployed’ rather than farmers.

But what if we are able to offer options to restore soils and ecosystems while ensuring short-term benefits and support farmers, even financially, during such a transition? What if farmers can get other rewards from restoring their landscapes, not only economic but also social, and even spiritual, through engaging in collective action within their communities? Utopia? Just see an example from Brazil’s agroecology movements on this video:

A short video with the testimony of a farmer from the agroecological movement of Minas Gerais, Brazil, shot in 2013 by Simone de Hek.
A short video with the testimony of a farmer from the agroecological movement of Minas Gerais, Brazil, shot in 2013 by Simone de Hek (click here to watch)

Assuming that smallholder farmers are unbiased utility maximizers that make decisions led exclusively by a short-term cost-benefit rationale is a big mistake. Incentives to restore degraded land may arise too from a sense of belonging, from social recognition, from concerns about a family’s future, or from sheer pride. It takes much more than just the mere promise of higher yields to motivate farmers to restore their soils.

(And, finally, why are we so ready to consider fertiliser subsidies but not prepared to think of smart subsidy mechanisms to foster diversification? For example, subsidies that can absorb the transaction and transition costs of implementing knowledge-intensive agroecological practices that were repeatedly shown to work on African soils…)

Produce more in western countries?

In the debate around agricultural production models necessary to achieve global food security it is often assumed that agricultural production has to increase everywhere in the world in order to meet current and future food demands.  Environmental damage and pollution, the destruction of habitats and the loss of biodiversity, the use of chemical and biological inputs that are harmful for humans, etc., etc… almost anything can be  justified in the name of “feeding the world”. As if these negative externalities from agriculture were  just unavoidable tradeoffs that humanity must internalise to be able to feed itself.

This is particularly the case in the most productive areas of the world, such as North America or Western Europe, and particularly in export-oriented countries like The Netherlands, where I participate very actively of this debate. I got tired of hearing people use the “feeding the world” argument to justify the need for irrational models of intensification per unit land or animal in already highly producing regions, which are both technical and economically inefficient. Since I noticed that such arguments were poorly informed by hard data, I came up with the figure below that appears in a paper we are about to publish(*):

Slide1click to enlarge

Do it yourself

You can build this figure at home. Just go to the FAOStat Database and download the necessary data, which in this case are: the average yield per country and the total production per country. No need for passwords or membership. As in the figure above, you can start by looking at cereals (maize, wheat, rice, etc.), which are the major staple crops for humanity. You can download and use the latest data, or use the last 10 or 20 years of data and compute averages. The figure above is built with the latest data available (2012, 2013). Sum up the cereal production of all the countries to obtain total world production, and calculate the relative production per country (%) by dividing country production by total world production, multiplied by 100. Finally, order the data series by increasing average yields and compute the cumulative frequency of the relative contribution of each country, from the least to the most productive one.

How to read this graph

As with any cumulative distribution graph you can ready it as a two-entry plot. For example, if you start from the vertical (y) axis, you can enter at the level 50% (i.e., half of the total world production) and move to the right until you hit the yellow line representing the cumulative frequency. From that point you can move downwards on a straight line until you reach the horizontal (x) axis. You’ll hit the x axis at the value 3.1 t/ha/year. This is the ‘median’ yield per country. This means that 50% of the total world cereal production comes from countries where cereal yields are smaller than 3.1 t/ha/year, whereas the other 50% comes from countries where the average yields are above that value.

Another way of reading this graph is to start from a point on the x axis, from a certain average yield per country. For example, the total production of all countries in which the average cereal yield is greater than 6 t/ha/year (most of western Europe and North America) represents barely 12.5% of the total world cereal production, as indicated by the blue dotted line. If we take the top 5 countries in terms of average yields, The Netherlands therein, all their production pulled together represents 0.02% of the total world production (second blue doted line). Most of the poorest countries in the world produce average yields of less than 2 t/ha/year, or around 1.3 t/ha/year on average, and contribute 15% to total world cereal production.

What does this mean?

The analysis suggest that further increasing yields in developed countries to be able to feed the word is not justified, or not a priority, as even doubling production in these countries will still contribute a relatively small fraction of the world demand (25% at most).  Since yield gains in response to input intensification follow the law of diminishing returns (i.e., the higher the productivity level the smaller the response to new inputs and their efficiency), increasing average yields by e.g. 1 t/ha/year in countries and regions where yields are already high requires larger investments (and potentially greater environmental damage) than in regions where yields fluctuate around 1.3 t/ha/year. Doubling current cereal yield in the least productive countries, from an average of 1.3 to 2.6 t/ha/year will have a greater impact on global food production and far less impact on the environment.

This means that, on a global scale, yields must increase but not everywhere, and not in any way or at any cost. Production must increase in places where people are hungry, and where their livelihoods as well as the national economies depend largely on agriculture. Twice as much land is used for agriculture in the poor cereal yield countries than in the high yielding ones, and many more people live from and depend on agricultural production in the former. But producing in these regions, under their specific social and ecological conditions, requires locally adaptive production models and technologies. This is where agroecology can play a major role.

The Netherlands

The argument that yields have to increase further in The Netherlands to be able to feed the world crumbles down very quickly when you put some data on the table. Why are our agricultural “experts” unaware of this? In my opinion, The Netherlands has a different role to play in the global food security quest: to deliver the necessary knowledge to produce food without inputs of fossil fuels, less dependence on pesticide or toxin-producing plants, and with less environmental externalities. As non-renewable resources used in agriculture are becoming scarcer, and as the impact of intensive agriculture on nature and society is increasingly irreversible, it is my opinion that The Netherlands should become the first fully ‘organic’ country. This will go at the expense of some productivity at the beginning. But with time productivity gaps will disappear and the knowledge generated during this transition will be invaluable for the design of new agricultural models to feed a future  world in a truly sustainable way.

(*) Pablo Tittonell, Laurens Klerkx, Frederic Baudron, Georges F. Félix, Andrea Ruggia, Dirk van Apeldoorn, Santiago Dogliotti, Paul Mapfumo, Walter A.H. Rossing2015. Ecological intensification: local innovation to address global challenges. Sustainable Agriculture Reviews, in press.



Enough food for everyone?

When it comes to discussing global food security the first argument that is put forward is that we need to increase production (by 70%? doubling yields?) in order to meet the demands of a growing and wealthier world population towards 2050. There is a number of weak assumptions around these estimates that I’m not going to address in this post but perhaps in a following one. Here, I would like to place emphasis not on quantity but on quality. While on a global scale we are producing enough calories to feed everyone (2720 Kcal per person per year produced, against 1800 to 2100 needed, according to the World Health Organisation of the UN), we know that we humans need more than just calories to stay alive and live a functional life.

At the same time we learn from medical doctors and nutritionists that diet is becoming the number one cause of death among humans – diets kill more people than wars or road accidents! This is why specialists at the Institute for Health Metrics and Evaluation of Washington University came up with a proposal for a balanced global diet – accounting for physiological and cultural diversity in food habits – designed not just to lose weight but to reduce the risk of diet related death. The major items in such a diet are indicated in the figure below, depicting in relative terms their current availability (yellow bars) and the level necessary to meet current human needs on a global scale (blue vertical line).


click to enlarge


While the current production of vegetables, nuts, fruits, milk and edible seeds are insufficient to meet world demands, the production of whole grains and fish are about 50% higher than human requirements, while the production of red meat is 568% higher than required for a healthy diet. This suggests that the generalised assumption that food production must increase is only true for certain food items (e.g., vegetables by 11%, seeds and nuts by 58%, fruits by 34%, etc.). Nuts, seeds and fruits, in particular, are for the most part tree crops. Does this mean that to meet future global food demands we will have to plant more trees or practice agroforestry?


A dubious trend…

The State of Food Insecurity in the World 2015 (SOFI), jointly published by the UN Food and Agriculture Organization (FAO), the International Fund for Agricultural Development (IFAD) and the World Food Programme (WFP) estimates that nearly 800 million people suffer from chronic undernourishment. The vast majority of the hungry live in developing countries – around 15 % of the world population. These figures are alarming! Yet, for the first time in human history, obesity outweighs hunger. The current number of overweight people in the world is estimated at 1300 million. These trends reveal not just problems in the distribution of resources or inequity in access to food worldwide, but also the effect of current patterns of food consumption.



click to enlarge