Limited environmental and yield benefits of intercropping practices in smallholder fields: Evidence from multi-source data

Li, Chengxiu; Kambombe, Oscar; Gulule Chimimba, Ellasy; Fawcett, Dominic; Brown, Luke; Yu, Le; Gadedjisso-Tossou, Agossou; Dash, Jadunandan

Abstract

Context
To ensure food security in sub-Saharan Africa, it is necessary to improve crop yields while minimizing environmental impacts. Intercropping has been demonstrated to deliver such outcomes, but their performance in smallholder fields has received limited attention therefore insufficient to capture the complexity of real-world crop fields run by smallholder farmers.

Objective
This study examines the benefits and management of intercropping practices in real smallholder fields in Malawi.

Methods
We collected field data on intercrop types, the number of intercropped species and maize yield in intercropped maize fields. Field data was then combined with geospatial and household survey data to investigate the yield benefits, agricultural inputs, and factors related to intercropping choices. We used Pearson correlation and Tukey’s test to test the statistical significance in the difference between intercropped fields and monoculture fields.

Results
We found that more intercrops were planted in fields with smaller sizes, drier conditions, and higher soil erosion levels, with adoption rates increasing from 75 % in 2010 to 84 % in 2020. In addition, our field data shows that intercropping is associated with reduced primary maize yield (2.7 t/ha) compared to pure maize yield (3.8 t/ha). Conversely, satellite data demonstrates an improvement in overall field yield in intercropped fields. Meanwhile, intercropped fields require higher labor inputs (11 h more per season) and increased weeding times than monocultures, however agrochemical inputs (fertilizers and pesticides) do not necessarily decrease in intercropped fields compared to monocultures.

Conclusions
Our results suggest that while smallholder farmers in Malawi adopt intercropping to improve land use efficiency, drought resilience, and soil fertility, they are not realizing the full benefits observed in experimental trials.

Implications
More evidence on the benefits and best practices of intercropping in smallholder fields is necessary in order to better understand this practice as an option for sustainable intensification.

• Journal Article Type: Article
• Acceptance Date: May 15, 2023
• Online Publication Date: May 19, 2023
• Publication Date: May 19, 2023
• Deposit Date: May 19, 2023
• Publicly Available Date: May 20, 2025
• Print ISSN: 0378-4290
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 299
• Article Number: 108974
• DOI: https://doi.org/10.1016/j.fcr.2023.108974