All you need to know about agriculture to understand ecology

Agriculture is affected by climate change in two ways. Firstly, it will have to adapt: changing climatic conditions will mean changing production methods, and extreme events (rain, drought) will multiply, putting harvests at risk. Secondly, it’s a fantastic solution: it captures an extraordinary quantity of carbon, and its biomass could help replace fossil fuels and raw materials.

So it’s one of the most fertile fields for ecological innovation. But there’s a danger: it’s misunderstood. The general public knows little about it, and politicians not much better. So how can we know what kind of change to encourage? To give society a real grasp of the subject and an insight into the complexity of agriculture, we’re going to look at these six main themes:

  • The history of agriculture
  • Agricultural production
  • Genetics in agriculture
  • Soil issues
  • Pests and how to manage them
  • Water and irrigation

I’ll go into more detail on two others later:

  • Animal husbandry
  • Forestry

Once you’ve read this dossier, you’ll understand why I often write “agricultures” in the plural.

The history of agriculture

“Farming does not just happen, whether it is ancient, historic or modern. It is an extremely complex process requiring great skill in balancing the different component elements, inputs and outputs, gambling against the greatest uncertainty of them all, the climate, and managing to have sufficient reserves to survive the worst possible outcome.Reynolds, ‘Ancient farming’, 1987, p. 49; Bieleman 2015, p.18

Farming began to appear in various parts of the world (Central America, the Near East, China…) from the 10th millennium B.C. and gradually spread throughout the world. It’s a fascinating story, which teaches us a great deal about modern agriculture.

For example, as far back as antiquity, French (and, in general, European) fields were entirely devoted to cereals or fallow land (with the exception of vines). Other vegetables and plants were grown on a small scale, in gardens. Animal husbandry played a central role in these systems: one of the main challenges was to successfully transfer plant matter from pastures to cultivated fields using livestock. In fact, this was the whole point of the medieval agricultural revolution: thanks to advances in mettalurgy, carts and wagons were developed, and it was finally possible (on a large scale) to stall livestock and make hay. The transfer of fertility from pasture to field was thus multiplied.

The most extraordinary point is that we only moved away from this fundamentally ancient form of agriculture in the second half of the 19th century, when fallow-free systems finally took over from archaic, fallow-based systems. We often speak of the agriculture of our grandparents as a (fortunately) very distant horizon. However, we must bear in mind that their own agriculture was extremely recent: they themselves were not far removed from an agronomy similar to that practiced in antiquity and focused exclusively on wheat.

To find out more, read our article on the history of agriculture.

Agricultural production

To understand agriculture, you need to know the statistics: how much wheat is produced worldwide? What are the major flows? Which countries are exporters/importers?

You also need to understand the economics. There are currently over 7 billion people to feed, and the number of malnourished people has risen from 8.4% in 2020 to 9.9% in 2021. The number of people facing hunger as defined by the FAO was between 720 and 811 million. Isn’t there enough food for everyone? How does the food production and distribution system work? We tend to forget that agriculture is an economic activity with a number of distinctive features, such as the importance of distribution channels, its land market and regulation, and its integration into the industrial ecosystem.

We’ll also take a closer look at each crop: how long has corn been grown in France? What is the history and geopolitics of rice? What is manioc?

It’s an extensive dossier that we’ll be presenting in our article on agricultural production.

Genetics in agriculture

Few fields are as misunderstood as genetics in agriculture. First of all, genetic engineering is as old as agriculture itself. Farmers have always tried to select the seeds with the best characteristics. The contrast is sometimes staggering when comparing modern plants with their ancestors, as in the case of corn and tomatoes.

More modern methods of genetic manipulation have been in use for many years in several countries: the USA, Canada, Australia, etc. Glyphosate-resistant GMOs (Roundup Ready) are well known, but they are far from being the only GMOs available. In particular, there are the “BT” varieties, which synthesize the insecticide bacillus thuringiensis. On average, these enable farmers to reduce the amount of insecticides they use and increase their income. But these are just two examples: the possibilities are multiplying. We are seeing the emergence of drought-resistant plants (= suffering less) and nutrient-enriched plants. Other very recent methods are opening up new prospects: NBT and CRISPR

We’ll finish with a look at the regulatory situation in the sector, which is tending to liberalize (except in Europe) and raises a very difficult question: what is a GMO?

To find out more: our article on genetics in agriculture.

Agricultural soils

Soil is something of a given for most people: it’s the brown stuff on the ground that sticks to your shoes. On the contrary, for agriculture, it’s a precious resource of fantastic complexity. First of all, it’s where the plant recovers its nutrients, so it has to have the right quantity of elements: phosphorus, potassium and nitrogen (=fertilizer).

It also has many other characteristics: its texture, its porosity (does it let water through or not?), the number of earthworms, its carbon content… Its capacity to “hold” is also important: a major problem worldwide is soil erosion, which can be washed away by rain or wind.

To find out more: our article on agricultural soils.

Pests and their management

There are many dangers that threaten crops. First, weeds can invade your fields. Not only is this a problem in terms of competition (they deprive your crops of resources), but it can also be a health problem. Many weeds are toxic, the best known being Datura.

Insects are obviously another threat. Everyone remembers the aphid invasion in 2020, which devastated beet crops by spreading a virus called dwarf yellows. Flea beetles are also currently a scourge, gradually invading France and devouring young shoots with their larvae.

Plants can also be colonized by fungi, the best-known of which is undoubtedly downy mildew. Very common, it was this fungus that caused a major famine in Ireland between 1845 and 1852. Another plague well known to farmers (and gardeners alike) is oidium.

Contrary to the somewhat romantic images that are often circulated, if you “let nature take its course”, you simply won’t have a harvest.

Description de cette image, également commentée ci-après
Flea beetle

Farmers have three types of solution to deal with these dangers:

  • Agronomic solutions, such as crop rotation
  • Chemical solutions, such as herbicides,
  • For weeds, tillage.

Somewhat transversely to all this, you have ” biocontrol “, which “is a set of plant protection methods based on the use of natural mechanisms”. This includes both purely “chemical” solutions, such as pheromones, and agronomic solutions, such as the introduction of ladybugs.

We’ll also look at the regulations governing plant protection products, which reflect the complexity of agriculture’s relationship with nature: it’s a question of sustainably mobilizing its strengths while containing its threats.

To find out more: our article on pests and pest management.

Water and irrigation

We often have the feeling that water is a given: it falls from the sky, all you have to do is turn on the tap to get some… Sometimes there are restrictions, but how much does that affect us? In agriculture, on the contrary, it’s an absolutely crucial issue. The quickest way to understand this is to look at the photosynthesis reaction: CO2 H2O (chlorophyll light) → (HCHO) O2. So no water, no photosynthesis, no plant. A plant without water literally suffocates.

Irrigation was one of the main levers of agricultural power in many ancient societies, such as Egypt and the Incas. Today, it’s a lever for protecting crop growth, particularly in the face of increasingly frequent droughts.

To find out more: our article on water and irrigation.

Livestock farming

Livestock farming is such a vast subject that I initially thought I’d deal with it on another site. In reality, however, it cannot be separated from the cultivation of plants. From the very beginning, the two activities have been inextricably linked. In Europe, for example, the main innovations in agriculture in the Middle Ages focused on manure management: the invention of carts, stables, etc. How could fertility be transported from pastures (saltus) to productive fields (ager)?

Even today, the two activities are inextricably linked: livestock farming adds value to a variety of crops, such as alfalfa or beet pulp, diversifying crop rotation and, in return, providing fertilizer.

To find out more: our article on livestock farming (coming soon).


The final aspect of agriculture is forestry. Is tree cultivation a crop like any other? What are its practices? What are its outlets?

To find out more: our article on forestry (coming soon).

The best people to talk to about agriculture are farmers. In particular, I invite you to follow @fragritwittos, a community of caring and interesting farmers (and what’s more, you’ll fill your feed with photos of pretty landscapes and cute animals <3). They’re the ones who made me aware of the complexity of farming. You’ll also find lots ofagriyoutubers who show and explain their work in concrete terms. Finally, you can find podcasts created by people who, like me, think we should understand agriculture better.