Global Study Reveals Environmental And Social Benefits Of Diversified Agriculture

Food security and biodiversity are both helped by diversified farming techniques, with little negative impact, according to a new paper that includes research from two Washington State University professors.

The study, published in the journal Science, involved 58 co-authors located at institutions on five continents.

“The results are overwhelmingly strong for all diversification strategies,” said David Crowder, a professor in WSU’s Department of Entomology. “The working theory is that diversity is good in agriculture, but I was surprised that the benefits were so strong.”

Crowder and his colleague Jeb Owen, an WSU associate professor in entomology, both contributed data to the paper, which was a meta-analysis of 28 global studies. In fact, neither Owen nor Crowder knew the other was involved in the paper until it was nearly published.

Owen’s contribution centered on wild birds and their impact on organic farms. His lab conducted surveys at 30 different locations in four states, including Washington, to look at costs and benefits from wild birds as well as each farm’s crop diversification.

“We found that the more complex and diverse a farm, the wider the diversity of wild birds it supported, and that the birds were a net positive for the farms,” Owen said.

Owen’s former graduate student, Olivia Smith, led his wild bird research and was another co-author on the new paper.

Wild, native birds fed on insect pests that damage crops, decreasing the need for pest-control measures, while not increasing pathogen spread or destroying crops, he said.

Crowder’s contribution included his lab’s research on canola and different tillage processes used by growers.

“There’s a lot of research at WSU looking at diversified farming and ways we can improve the sustainability of farms,” Crowder said. “This paper shows that WSU is plugged into global issues, and I hope we see more of this out of the university.”

Laura Vang Rasmussen of the University of Copenhagen is lead author on the new study and worked for nearly four years to coordinate and synthesize data from around the world.

“Our results from this comprehensive study are surprisingly clear,” Vang Rasmussen said. “While we see very few negative effects from agricultural diversification, there are many significant benefits. This is particularly the case when two, three, or more measures are combined. The more, the better, especially when it comes to biodiversity and food security.”

The researchers saw the greatest positive effects on food security, followed closely by biodiversity. Furthermore, social outcomes in the form of well-being also improved significantly.

Among the many strategies adopted, livestock diversification and soil conservation had the most positive outcomes.