Cereal-legume intercropping: a smart review using topic modelling

Sofie Landschoot; Riccardo Zustovi; Kevin Dewitte; Nicola P Randall; Steven Maenhout; Geert Haesaert

doi:10.3389/fpls.2023.1228850

Cereal-legume intercropping: a smart review using topic modelling

Front Plant Sci. 2024 Jan 8:14:1228850. doi: 10.3389/fpls.2023.1228850. eCollection 2023.

Authors

Sofie Landschoot¹, Riccardo Zustovi¹, Kevin Dewitte¹, Nicola P Randall², Steven Maenhout¹, Geert Haesaert¹

Affiliations

¹ Department of Plants and Crops, Faculty of BioScience Engineering, Ghent University, Ghent, Belgium.
² Centre for Evidence-Based Agriculture, Harper Adams University, Newport, United Kingdom.

Abstract

Introduction: Over the last decade, there has been a growing interest in cereal-legume intercropping for sustainable agriculture. As a result numerous papers, including reviews, focus on this topic. Screening this large amount of papers, to identify knowledge gaps and future research opportunities, manually, would be a complex and time consuming task.

Materials and methods: Bibliometric analysis combined with text mining and topic modelling, to automatically find topics and to derive a representation of intercropping papers as a potential solution to reduce the workload was tested. Both common (e.g. wheat and soybean) as well as underutilized crops (e.g. buckwheat, lupin, triticale) were the focus of this study. The corpus used for the analysis was retrieved from Web of Science and Scopus on 5^th September 2022 and consisted of 4,732 papers.

Results: The number of papers on cereal-legume intercropping increased in recent years, with most studies being located in China. Literature mainly dealt with the cereals maize and wheat and the legume soybean whereas buckwheat and lupin received little attention from academic researchers. These underutilized crops are certainly interesting to be used as intercropping partners, however, additional research on optimization of management and cultivar's choice is important. Yield and nitrogen fixation are the most commonly studied traits in cereal-legume intercropping. Last decade, there is an increasing interest in climate resilience, sustainability and biodiversity. Also the term "ecosystem services" came into play, but still with a low frequency. The regulating services and provisioning services seem to be the most studied, in contrast terms related to potential cultural services were not encountered.

Discussion: In conclusion, based on this review several research opportunities were identified. Minor crops like lupin and buckwheat need to be evaluated for their role as intercropping partners. The interaction between species based on e.g. root exudates needs to be further unraveled. Also diseases, pests and weeds in relation to intercropping deserve more attention and finally more in-depth research on the additional benefits/ecosystem services associated with intercropping systems is necessary.

Keywords: cereal; intercrop; legume; text mining; topic model.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study is part of the CROPDIVA project “Climate Resilient Orphan croPs for increased DIVersity in Agriculture” funded by the EU’s Horizon 2020 Research and Innovation Program (Grant Agreement No. 101000847).