Crop rotational diversity can mitigate climate-induced grain yield losses

Authors: COSTA, ALESSIO - Swedish University Of Agricultural Sciences; BOMMARCO, RICCARDO - Swedish University Of Agricultural Sciences; SMITH, MONIQUE - Swedish University Of Agricultural Sciences; BOWLES, TIMOTHY - University Of California Berkeley; GUADIN, AMELIE C.M. - University Of California, Davis; WATSON, CHRISTINE - Swedish University Of Agricultural Sciences; BERTI, ANTONIO - Universita Di Padova; BLECHARCZYK, ANDRZEJ - Poznan University Of Life Sciences; CALDERON, FRANDISCO - Oregon State University; Osborne, Shannon; Schmer, Marty

Submitted to: Global Change Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2024
Publication Date: 3/31/2024
Citation: Costa, A., Bommarco, R., Smith, M.E., Bowles, T., Guadin, A., Watson, C.A., Berti, A., Blecharczyk, A., Calderon, F.J., Osborne, S.L., Schmer, M.R., et al. 2024. Crop rotational diversity can mitigate climate-induced grain yield losses. Global Change Biology. 30(5). Article 317298. https://doi.org/10.1111/gcb.17298.
DOI: https://doi.org/10.1111/gcb.17298

Interpretive Summary: Crop rotations enhance cereal grain yields; however, crop rotations have become simplified and grain yields are vulnerable to stressful conditions increasingly common under climate change. Increasing the diversity of crop rotations is a potential solution to reducing grain yield losses from adverse climatic conditions. We quantified the effect of climatic conditions on small grain and maize yields with increasing crop rotational diversity in 32 long-term field experiments across Europe and North America. Rotations that were crop species diverse and functionally rich enhanced yields across all climatic conditions. Diverse crop rotations mitigated yield losses from anomalously warm conditions, long and warm dry spells, and anomalously wet (for small grains) or dry (for maize) conditions. The maximum yield benefits of diverse crop rotation under detrimental climatic conditions exceeded the average yield of a monoculture cereal grain under non-detrimental climatic conditions. Crop species diversity could be adjusted to maximize yield benefits, depending on climatic conditions. Crop functional richness had a larger effect on cereal grain yield benefits compared with species diversity alone, providing more consistent benefits across climatic conditions. Diversifying rotations with functionally distinct crops provides adaptation of cropping systems to global warming and precipitation changes to protect global crop production.

Technical Abstract: Crop rotations enhance cereal grain yields, but have become simpler and yields more vulnerable to stressful conditions increasingly common under climate change. Diversified crop rotations are suggested as a way to reduce grain yield losses from adverse climatic conditions. We quantified how climatic conditions affect small grain and maize yields with gradually increasing crop rotational diversity (CRD) in 32 long-term (10-63 years) field experiments across Europe and North America. Species-diverse and functionally rich rotations enhanced yields across all climatic conditions. They also mitigated yield losses from anomalous warm conditions and long and warm dry spells, as well as from anomalous wet (for small grains) or dry (for maize) conditions. The maximum yield benefits of CRD under detrimental climatic conditions exceeded the average yield of monoculture under non-detrimental climatic conditions. Crop species diversity could be adjusted to maximize yield benefits, depending on climatic conditions. Crop functional richness had a larger effect on CRD yield benefits compared with species diversity alone, providing more consistent benefits across climatic conditions. Diversifying rotations with functionally distinct crops provides adaptation of cropping systems to global warming and potentially to changes in precipitation.