“Paleoartists” attempt to hone their craft and captivate the public even as they grapple with emerging data that alter how we see dinosaurs.
Image credit: Mark Witton.
New Research In
Physical Sciences
Featured Portals
Articles by Topic
Biological Sciences
Featured Portals
Articles by Topic
Edited by Hans Herren, Millennium Institute, Washington, DC, and approved December 19, 2019 (received for review April 23, 2019)
Significance
Organic agriculture promotes environmental and socioeconomic sustainability to a greater degree than conventional agriculture. However, it is unknown whether effects of organic agriculture on sustainability metrics such as biodiversity, crop yields, and profitability vary across the diverse landscapes where organic farming is practiced. We addressed this using a global meta-analysis spanning 60 crops. Organic sites had greater biodiversity than conventional ones, with the largest benefits in landscapes with large field sizes. In contrast, while organic sites also had greater profits, the largest benefits occurred in landscapes with small fields. The ecological sustainability benefits of organic agriculture are most pronounced in landscapes typified by more intensive agriculture, while economic benefits are likely influenced by socioeconomic factors and yields.
Abstract
Organic agriculture promotes sustainability compared to conventional agriculture. However, the multifunctional sustainability benefits of organic farms might be mediated by landscape context. Assessing how landscape context affects sustainability may aid in targeting organic production to landscapes that promote high biodiversity, crop yields, and profitability. We addressed this using a meta-analysis spanning 60 crop types on six continents that assessed whether landscape context affected biodiversity, yield, and profitability of organic vs. conventional agroecosystems. We considered landscape metrics reflecting landscape composition (percent cropland), compositional heterogeneity (number and diversity of cover types), and configurational heterogeneity (spatial arrangement of cover types) across our study systems. Organic sites had greater biodiversity (34%) and profits (50%) than conventional sites, despite lower yields (18%). Biodiversity gains increased as average crop field size in the landscape increased, suggesting organic farms provide a “refuge” in intensive landscapes. In contrast, as crop field size increased, yield gaps between organic and conventional farms increased and profitability benefits of organic farming decreased. Profitability of organic systems, which we were only able to measure for studies conducted in the United States, varied across landscapes in conjunction with production costs and price premiums, suggesting socioeconomic factors mediated profitability. Our results show biodiversity benefits of organic farming respond differently to landscape context compared to yield and profitability benefits, suggesting these sustainability metrics are decoupled. More broadly, our results show that the ecological, but not the economic, sustainability benefits of organic agriculture are most pronounced in more intensive agricultural landscapes.
Footnotes
- ↵1To whom correspondence may be addressed. Email: olivia.m.smith{at}wsu.edu.
Author contributions: O.M.S., A.L.C., J.P.R., M.S.J., R.J.O., J.M.T., J.H.T., K.A.C., R.L.O., Y.G., C.M.K., and D.W.C. designed research; O.M.S., A.L.C., M.S.J., R.J.O., J.M.T., J.H.T., K.A.C., R.L.O., Y.G., and D.W.C. performed research; O.M.S. and D.W.C. analyzed data; and O.M.S., J.P.R., and D.W.C. wrote the paper.
The authors declare no competing interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at https://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1906909117/-/DCSupplemental.
Published under the PNAS license.
Log in using your username and password
Purchase access
You may purchase access to this article. This will require you to create an account if you don't already have one.
Landscape context affects the sustainability of organic farming systems
Sign up for Article Alerts
Article Classifications
- Biological Sciences
- Agricultural Sciences
Jump to section
You May Also be Interested in
Coral reef bleaching frequently makes headlines, but researchers are still trying to sort out the cellular mechanisms at work.
Image credit: The Ocean Agency/XL Catlin Seaview Survey.
Greenhouse gas emissions in the first decades of the 21st century are likely to affect global sea level for centuries, and limiting long-term sea-level rise might require stringent near-term emission reductions.
Image courtesy of Lucy Reading-Ikkanda (artist).
A single formulation combining two gene therapies treated an array of age-related disorders in mice.
Image courtesy of Pixabay/Sipa.
Many ecosystems in the United States may be vulnerable to increased fire occurrence and frequency caused by invasive grasses.
Image courtesy of Pixabay/Stevepb.