According to a new paper published in the journal Nature Communications, biodiversity is an economically relevant factor of production for farmers.
In agricultural settings, plant diversity is often associated with low biomass yield and forage quality. However, is this assumption true?
Over a period of one year, researchers assessed plant diversity effects on biomass yield, forage quality, quality-adjusted yield, and revenues across different management intensities on subplots of a large-scale grassland biodiversity experiment.
This approach allowed the team to quantify the economic added value of biodiversity.
“Biodiversity is often considered unprofitable, but we show that it can, in fact, pay off,” says Nina Buchmann, Professor of Grassland Sciences at ETH Zurich.
The quality of forage remains more or less the same when the number of plant species growing in a field is increased from 1 to 16, however, the yield is higher – directly correlating with potential income from milk sales.
“The resultant increase in revenues in our study is comparable to the difference in yield between extensively and intensively farmed land,” says Sergei Schaub, lead author of the study and a doctoral student in Finger’s and Buchmann’s groups.
The team used data from the long-term Jena Experiment, which compared different farming practices at the same site.
“Our results show that biodiversity has an economically positive effect on all areas, regardless of whether farmers mow and fertilise them four times a year or just once,” Schaub says.
Biodiversity as Risk insurance
What’s more, “biodiversity acts as a kind of risk insurance,” said Buchmann.
If grasslands are diverse they are better able to cope with extreme conditions such as droughts or floods. This is because different species of plant react differently to environmental influences, which can partially compensate for any losses.
“This means yields become more stable over time,” Buchmann says.
“Preserving or restoring diverse grasslands can be a win-win situation,” the researchers said at the end of the paper.
Schaub, S., Finger, R., Leiber, F. et al. Plant diversity effects on forage quality, yield and revenues of semi-natural grasslands. Nat Commun 11, 768 (2020). https://doi.org/10.1038/s41467-020-14541-4