Increasing crop rotational diversity can enhance cereal yields

Authors: SMITH, MONIQUE - Swedish University Of Agricultural Sciences; VICO, GIULIA - Swedish University Of Agricultural Sciences; COSTA, ALESSIO - Swedish University Of Agricultural Sciences; BOWLES, TIMOTHY - University Of California; GUADIN, AMELIE - University Of California, Davis; HALLIN, SARA - Swedish University Of Agricultural Sciences; WATSON, CHRISTINE - Swedish University Of Agricultural Sciences; ALARCON, REMEDIOS - The National Institute For Agricultural And Food Research And Technology (INIA); BERTI, ANTONIO - Universita Di Padova; BLECHARCZYK, ANDRZEJ - Poznan University Of Life Sciences; Lehman, R - Michael; Osborne, Shannon; Schmer, Marty

Submitted to: Communications Earth & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/6/2023
Publication Date: 3/23/2023
Citation: Smith, M.E., Vico, G., Costa, A., Bowles, T., Gaudin, A.C.M., Hallin, S., Watson, C.A., Alarcon, R., Berti, A., Blecharczyk, A., Francisco, F.J., Culman, S., Deen, W., Garcia, A.G., Garcia-Diaz, A., Plaza, E.H., Jonczyk, K., Jack, O., Lehman, R.M., Montemurro, F., Morari, F., Onofri, A., Osborne, S.L., Pasamon, J.L.T., Sandstrom, B., Santin-Montanya, I., Sawinski, Z., Schmer, M.R., Stalenga, J., Strock, J., Tei, F., Topp, C.F.E., Ventrella, D., Walker, R.L., Bommarco, R. 2023. Increasing crop rotational diversity can enhance cereal yields. Communications Earth & Environment. 4(1). Article 89. https://doi.org/10.1038/s43247-023-00746-0.
DOI: https://doi.org/10.1038/s43247-023-00746-0

Interpretive Summary: Sustainable food production requires reducing negative impacts of crop production on air, soil, and water quality while maintaining crop yields. Diversified crop rotations are a promising management practice to meet the needs of sustainable food production. However, it is unclear how crop yields change with crop rotational diversity over extended durations, and whether it is the number of different crops or number of crop functional groups in the rotation which provide the most benefits. We analyzed crop yields for small grain cereals and maize from 32 long-term experiments across Europe and North America, with each field experiment comprising contrasting diversity levels and nitrogen (N) fertilizer inputs. Crop yields benefited from increasing the number crop species as well as crop functional diversity. Crop yields generally increased over time with crop rotational diversity, although winter-sown small grain cereal yields declined over time at the highest level of crop rotation diversity. Rotational diversification was beneficial in all crops at low N fertilization, and particularly so in maize, indicating enhanced N-use efficiency. Our results suggest that crop functional diversity provides niche complementarity in resource use, thereby enhancing yields while decreasing fertilizer requirements and protecting air, soil, and water resources.

Technical Abstract: Sustainable food production requires reducing negative impacts of crop production on the environment and climate while enhancing yields. Diversifying agriculture by rotating a greater number of crop species in sequence is a promising practice to achieve this 1,2. However, it is unclear how crop yields change with Crop Rotational Diversity (CRD), and over time, and whether diversity of crop functional groups in the rotation provide the most benefits. We analysed crop yield data (28 973 yield observations) for small grain cereals and maize from 32 long-term (10-63 years) experiments across Europe and North America, each comprising contrasting diversity levels and nitrogen (N) fertiliser input. Yields benefited from increasing crop species and functional diversity and also increased over time although winter-sown small grain cereals declined at the highest diversity level. Diversification was beneficial in all crops at low N fertilisation, and particularly so in maize, pointing to enhanced N-use efficiency. Our results suggest that crop functional diversity provides niche complementarity in resource use, thereby enhancing yields while decreasing the reliance on fertilisers, a source of greenhouse gas emissions and water pollution.