Research topics in crop diversification research at the landscape level: early evidence from a text mining approach

Crop diversification has many benefits at the cropping and food systems levels and has been addressed in agricultural research (Hufnagel et al., 2020). Landscape design and management in agricultural regions can support crop diversification by building bridges with scientific domains like ecology and geography (Benoit et al., 2012). However, little is known about how the research community has addressed crop diversification from a landscape perspective. In this paper, we investigated a bibliographic corpus retrieved from the Scopus database papers coupling crop diversification and landscape (in title, abstract and keywords), retrieving 461 papers for the period 1990 to 2020. The corpus was analysed using the CorText platform (e.g., Ruiz-Martinez et al., 2015). First, natural language processing was used to extract multi-terms from title, abstract and keywords. Then, we mined the temporal dynamics and co-occurrence of the 100 most frequent terms. Our findings showed that species richness emerges as the main topic in this corpus and that natural enemies, crop types and natural control increased in importance. In recent years, genetic diversity, climate change and agricultural production also gained attention. On the contrary, land use and some terms related to diversity (landscape, plant and farmland) were marginal or decreasing. By analysing the terms co-occurrence over the three decades, we observed that the papers addressing crop varieties and agroforestry systems split into two streams: one about agricultural production in relation to climate change, and the other about farm size and land use. Instead, the functional diversity and field margin disappeared from the recent literature. Land use patterns and landscape diversity converged mainly on studies about biological pest control. Altogether, the corpus highlighted that the spatial configuration lost importance when addressing crop diversification. In addition, the species diversity gained attention finally catching a large part of the literature in the corpus. From a landscape approach perspective, we might point out the apparent lack of a major topic: the involvement of the local community and stakeholders. Our simple and rapid text-mining approach yielded early evidence of knowledge gaps about the landscape level in crop diversification literature. The expected contribution of approaching crop diversification at the landscape level would be to provide a relevant framework for the characterisation of the baseline system to be diversified. In particular, the landscape agronomy perspective stressed the need to define the scale and target area for crop diversification consistently with (natural and cultivated) species diversity embedded in a local socio-technical system.