Sustainable agriculture calls for a systematic approach

Tim Benton from the University of Leeds argues that sustainable agriculture is a more complex concept than it appears and that, if misunderstood, it can worsen environmental impacts.

By Fábio de Castro

Agência FAPESP – Sustainable agriculture is a more complex concept than it appears at first sight. If the principle is not well understood, systematically implemented and correctly managed, it can worsen instead of reduce the environmental impacts of agriculture.

This warning was issued by British scientist Tim Benton, coordinator of the University of Leeds Global Food Security Programme (in the UK) during the Forum on Science, Technology and Innovation for Sustainable Development held in Rio de Janeiro in June.

According to Benton, the concept of sustainable agriculture is frequently poorly defined and, therefore, poorly understood and applied.

“It is necessary to achieve a balance between the use of land for production and for the conservation of biodiversity. Different landscapes play different roles in different agro-environmental situations. Sustainable agriculture must be systematically managed on the scale of the entire landscape, with neither an isolated focus on farms nor only on the national scale,” he told Agência FAPESP.

Benton says that sustainable agriculture is a concept that everyone thinks they understand but that people—including managers—rarely perceive how complex it actually is. First, he says that the numerous impacts a farm has on the environment must all be taken into account, including the quality of the water found there, the use of land and the farm’s biodiversity.

“There are many impacts, and to reduce them a trade has to be made. Low-carbon agricultural activity will typically require more land to produce the same amount of food as traditional agriculture,” he said.

“Because it must use more land, such agricultural activity will have a greater effect on biodiversity. Low-carbon agriculture can, at the end of the chain, have a great impact on biodiversity,” affirmed Benton.

Another factor that makes the concept of sustainable agriculture complex is the scale upon which it is managed. The consequences of managing a plot of land are not limited to that location, says the British scientist.

“When you manage a farm, the impacts of the activity extend beyond the territory in question. What happens with the greenhouse gases emitted there can have a global impact. The impact on water quality in streams and rivers can have a very broad reach, causing nitrification of coastal marine fishing grounds because of pollution in continental waterways,” he stated.

The situation becomes even more complex when the market impact is considered. “You can reduce agricultural yield in a country thinking that it is more sustainable. But the demand will remain the same or even increase. Thus, if you reduce yield, someone somewhere will have to increase yield, and this comes with negative environmental impacts,” said Benton.

Land management

In locally based production, some plots of a plantation can be managed in an unsustainable manner, while other parts can compensate for this drawback by being managed in a highly sustainable manner. However, what is true for an isolated plot of land is not always true on the scale of landscape, nation and continent, or on the global scale.

“In addition to the far-reaching environmental impacts are the economic impacts, which also repeat themselves environmentally, so we end up having a very complex concept,” said Benton.

Despite its complexity, agricultural sustainability is not unviable according to Benton. For it to work, land management must be thought out systematically, from the small scale through the global scale, with special focus on the scale of the landscape.

“On the level of landscape, we can manage not only farmable land but also the unfarmed land that is fundamental for agricultural activity because it maintains the pollinizers, the natural enemies, the microclimates and so forth,” he said.

On the national scale, it is necessary to have certain areas used especially for agricultural production and others reserved to guarantee other services. Each area plays its role, and one should balance out the other. However, the specifications also change on a continental scale. Some areas are good for producing fruit, while others are good for carbon capture and storage, for example.

“It is fundamental to manage agriculture in such a way that all these roles can be fulfilled. Doing things the same way in every scenario would be a disaster. Just because we can’t define sustainable agriculture does not mean that we can’t practice it,” said Benton.

“But being sustainable isn’t just a question of minimizing the carbon produced. It’s much more complicated than that. The long-term effects have to be taken into account, as does management at the scale of the landscape,” he affirmed.

Determining the criteria for agricultural management is a great challenge to developing sustainable agriculture, according to Benton. He says that for sustainable agriculture to happen, a strong government is needed. When locally based production is successful on one plot of land, the temptation is to expand.

“When a cultivated plot generates money, the farmer tends to want to double its area. If he’s successful, he will quadruple it, and soon we have a huge area converted for just one use,” he said.

“This scenario can be positive in the beginning, but if everyone does the same thing, everyone will suffer the consequences in the long run. It is good to think about agricultural growth, but at some point someone has to say ‘that is enough growth’,” he pointed out.

According to Benton, the process of achieving sustainable agriculture while maintaining profits is called sustainable intensification. When there are limits to the land area that can be converted for agriculture, more must be produced on the same area.

“But this intensification can’t be done in a way that is damaging to the environment. It must be done so as to minimize the impacts. Sustainable intensification can be done with new technologies, intelligent agriculture and landscape management,” he affirmed.