Disentangling weed diversity and weather impacts on the long-term crop production in a wheat-legume rotation

Authors: GONZALEZ-ANDUJAR, JOSE - Institute For Sustainable Agriculture; AGUILERA, MARIA - Universidad De Cordoba; Davis, Adam; NAVARRETE, LUIS - Instituto Nacional De Investigacion Y Technologia Agraria Y Alimentaria

Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/2018
Publication Date: 12/21/2018
Citation: Gonzalez-Andujar, J.L., Aguilera, M.J., Davis, A.S., Navarrete, L. 2018. Disentangling weed diversity and weather impacts on the long-term crop production in a wheat-legume rotation. Field Crops Research. 232:24-29. https://doi.org/10.1016/j.fcr.2018.12.005.
DOI: https://doi.org/10.1016/j.fcr.2018.12.005

Interpretive Summary: The role of weed species diversity in crop yield loss remains an open question. Some authors have found that more diverse weed communities result in less crop yield loss, while others have found the opposite result. We used a systems modeling approach to examine long-term data (31 years) from a cereal–legume crop rotation in central Spain to determine the relative importance of weed diversity and weather on the ability of weeds to compete with crops. Our analyses showed that the legume crop was not affected by weed diversity but was instead negatively influenced by average growing season temperature. In wheat, crop yield loss to weeds was lower under more diverse weed communities, and in cooler growing seasons. An improved understanding of the influence of weed diversity on crop yield may help to anticipate the effects of climate change and guide management practices to maintain crop productivity under shifting weed communities.

Technical Abstract: Weeds can harm crop growth and yield by competing for light, water, and nutrients and can produce high global yield losses if not controlled. However, the effects of weed diversity have not been fully examined. Here, we have used long-term data (31 years) of a cereal–legume rotation from a locality in central Spain to determine the importance of internal and external (weather and weed diversity) factors on crop yield. We used a novel method based on dynamic systems models to explore how weed diversity and weather factors interact with crop yields. The dynamic model used here integrated internal and external factors with additive or non-linear variants. We showed that internal processes (self-regulation) are involved in wheat and legume yield temporal fluctuations. The self-regulation of crop production appears to be stronger in cereal (85%) than in legume (45%) systems, and therefore legumes seems to be more sensitive to external variations. The legume crop was not affected by weed diversity but was instead negatively influenced by average temperature for the growing season. In wheat, there was a negative, non-linear response of yield to the interaction between richness and minimum temperature for the growing season. An improved understanding of the influence of weed diversity on crop yield may help to anticipate the effects of climate change and guide management practices to maintain crop productivity under sustainable agriculture.