Which is better, conventional or organic farming?

Which is better, conventional or organic farming?

Researchers writing in the journal Natural durability indicate that life cycle analysis (LCA), one of the most common methods for assessing the environmental impacts of agriculture and food, often tends to overlook vital factors, such as biodiversity, soil quality, pesticide impacts and societal changes. These oversights could lead to erroneous conclusions about the merits of intensive and organic farming, the report reveals.

According to three French, Danish and Swedish researchers, the implementation of LCA is too simplistic and misses the benefits of organic farming. Studies using LCA sometimes claim that organic farming is worse for the climate, as it has lower yields, and therefore uses more land to compensate for this.

“We fear that the ACV portrays too narrowly, and we risk making the wrong decisions politically and socially. When comparing organic and intensive farming, there are wider effects that the current approach does not sufficiently take into account,” said Hayo van der Werf, of the French National Institute for Agricultural Research.

Biodiversity, for example, is important for the health and resilience of ecosystems. However, it is in decline globally, with intensive agriculture proving to be a major driver of negative trends such as the decline of insects and birds. Agriculture occupies more than a third of the world’s land area, so any link between biodiversity loss and agriculture is important.

“But our analysis shows that current LCA studies rarely take biodiversity into account and therefore typically miss this broader benefit of organic farming. Previous studies have already shown that organic fields support around 30% higher levels of biodiversity than conventional fields,” said Marie Trydeman Knudsen from the University of Aarhus, Denmark.

The use of pesticides is another factor to consider; the increasing use of pesticides has led to pesticide residues in soil, water and food, which can be harmful to human health, terrestrial and aquatic ecosystems, and lead to biodiversity loss. Organic farming, on the other hand, excludes the use of synthetic pesticides, but few LCA studies report on these effects. Land degradation and declining soil quality resulting from unsustainable land management are also problematic and are rarely measured in LCA studies, which often overlook the benefits of organic farming practices such as varied crop rotation and the use of organic fertilizers. The researchers say that LCA generally assesses environmental impacts per kilogram of product, thus favoring systems that can have lower impacts per kilogram, while having higher impacts per hectare of land.

“LCA just looks at overall returns. Of course, from this point of view, it is true that intensive farming methods are indeed more efficient. But this is not the whole story of the agroecosystem as a whole. A diverse landscape with smaller fields, hedgerows and a variety of crops provides other benefits – greater biodiversity, for example,” said Christel Cederberg of Chalmers University of Technology, Sweden.

The product-based approach to LCA also fails to capture the intricacies of smaller, more diverse systems that are more dependent on ecological processes and are adapted to local soil, climate and ecosystem characteristics. The researchers note that efforts are being made in this area, but further progress is needed.

“We often look at effects at the global food chain level, but we need to be much better at considering environmental effects at the local level,” Knudsen said.

Researchers argue that current LCA methodology and practice is not good enough to assess agroecological systems such as organic farming. It needs to be improved and integrated with other environmental tools to get a more balanced picture.

Image credit: Yen Strandqvist/Chalmers

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