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Agriculture

Biodiversity and its effect on food supply

Industrial agriculture and intensive farming are commonplace these days and have led to a big reduction in the number of species on our fields. What does that mean for global food supply?

A farm worker distributes soybeans on a truck

Soybeans are one of the world's four staple grains

Medium-sized fields, a pond, mixed orchards, sheep, goats, cows and pigs grazing on a field and a herb garden at the back of the house - that's what a farm looked like in Europe at the beginning of the 20th century.

More than a hundred years later, it is a completely different picture. For the most part, production is in the hands of big concerns, which practice intensive farming for maximum yield and profits.

By focusing production on specific animals and plants, biodiversity in agriculture has been greatly reduced. Germany's Federal Agency for Nature Conservation (BfN) estimates that there has been a 90-percent decrease in the number of crop species since the beginning of the 20th century. Farm animals have suffered a similar fate: In the last 100 years, around 1,000 of the 6,500 known species have become extinct worldwide.

child hugging a cow

Is the rural idyll a thing of the past?

There has been a particularly marked effect on rice, maize, soybeans and wheat - the most important crops, which make up over 90 percent of global crop production.

"And among those, there are very few sub-species still being planted," said Andreas Krug, who heads the BfN's Sustainable Agriculture division.

Few plants feed the masses

But it is not just diversity that suffers from mass production. In areas with highly industrialized farms, the water shows high levels of nitrates and pesticides. Another problem with intensive farming is soil erosion, as the fields lie barren for part of the year or because crops like maize generally speed up erosion.

"And that leads to a loss of arable land," said Krug.

The main reason for the industrialization of farming is the rising demand for animal feed, especially maize and soybeans, according to agricultural economist Ernst Berg. Global economic growth has "led to a change in eating habits. People consume more meat and dairy and less plant-based food," he explained.

wheat field

Germany has 400 species of wheat, but only 30 are commercially viable

It takes 20 times more land to produce 100 grams of meat than the equivalent amount of grain. But the available land is getting smaller to make way for more housing, roads and other developments. In the industrialized world, a certain percentage of the arable land has to lie fallow to avoid soil erosion.

In developing countries, Berg said, arable land also suffers "due to environmental factors such as reduced soil quality, desertification, insufficient use of fertilizer or because the fields have not been watered efficiently; if fields get flooded, most of the water just evaporates and the soil gets too salty."

Fight for land

Global crop production would be enough to feed everybody, but, at the moment, worldwide, more food is being consumed than produced, as so many crops are used for feed and fuel. And that leads to ever more crops being farmed on the available land.

Ernst Berg

Berg says biodiversity doesn't always help

According to Berg, this situation is bound to lead to intensive farming and bigger agricultural units.

Andreas Krug disagrees. He does not believe that intensive farming and monocultures will ensure there is enough food to go around. He insists biodiversity is the key to effective farming, as it makes the soil more resilient.

"We need biodiversity for an adequate supply of food," Krug said, adding that it is important to rotate crops. "Plant one crop on one field and a different one on the one next to that; that way you spread the risk," he explained.

He also says that farmers need to use crops that adjust to the local climate, the soil, the water supply and the kinds of parasites and pests common to specific areas, especially those that have recurring famines.

Distributing economic resources fairly is another important factor, according to Krug. Small farms should get the rights to the land they farm, because their work ensures that the people get enough food. They should use crops that have adapted to local conditions, rather than imported high-performance crops that often need expensive fertilizers and pesticides that can make those farmers financially dependent.

Resilience through diversity

There are other, practical, advantages to farming in this way. "It's really important that bees and other insects pollinate crops," Krug said, adding that the same applies to fruit trees and vegetables.

He recommends leaving field borders to grow wild to encourage insects and birds to settle there, which can help fight pests the natural way. "To a certain extent, we can prevent a parasite epidemic that way," Krug said. In addition to that, hedges can provide protection against wind, which can speed up soil erosion.

rabbit in a field

Rabbits are after our food

Berg, on the other hand, is doubtful that protecting biodiversity necessarily helps farming all that much. He admits that ecosystems need to be functional for agriculture to work, but he believes it should not be overdone.

"If bees are needed for pollination, then, yes, you have to ensure the land is suitable for bees," Berg said. But sometimes, biodiversity can be counterproductive. Rabbits and partridges, for example, are not useful to farmers at all. "Pigeons, hamsters, cornflowers and corncockles are simply competing species jostling for space," he explained.

Thus, if you are aiming to get as much yield as possible from the land, you cannot preserve the natural habitat with all its flora and fauna at the same time. "It's a conflict that can't be resolved," Berg said.

So, there's the desire to preserve biodiversity on the one hand and the need to ensure food supply on the other. That poses an ethical dilemma that can only be solved through political means.

The German government has adopted a national strategy on biodiversity, and the EU in future also plans to peg its agricultural subsidies to farmers' efforts to encourage biodiversity through crop rotation and field borders.

But these measures are unlikely to have an effect on soybean production, for example, since that is mainly harvested in South America. Berg also believes that the genetic diversity of crops is not actually in danger, and he also does not think biodiversity needs to happen in the field as it were.

"In theory, we can do this in the lab, with gene banks," he said, adding that those gene banks are now commonplace around the world so that new strands can be developed or old ones revived.

Author: Fabian Schmidt / ng
Editor: Nancy Isenson

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