Evaluating the Effect of Intercropping on Arthropod Abundance, Weed Suppression and crop performance

Sammanfattning

Sustainable agriculture requires farming systems that promote biodiversity, resources use effectively and reduce external input usage. Intercropping has been proposed as a strategy to increase ecological resilience while maintaining productivity. The intercropping effect of winter wheat-winter pea (W+P) and winter oilseed rape-winter pea (R+P) on above ground dwelling arthropod abundance, suppressing weeds, enhancing crop biomass, and sustaining grain yield was evaluated compared to their sole strip cropping (SSC), and with their large field reference sole cropping plots (Ref). Field experiments were conducted in the 2023/2024 crop production season at SITES Lönnstorp Research Station, Skåne, southern Sweden. Abundance of aboveground dwelling arthropods was quantified by using pitfall traps and analysed with Generalized Linear Mixed Models (GLMM), while weed biomass, crop biomass, and grain yield were quantified with Linear Mixed Models (LMM). Tukey-adjusted pair-wise comparisons of estimated marginal means were used for treatment comparisons. Land Equivalent Ratio (LER) was computed for land-use efficiency comparison and correlation analysis was performed to examine the relationships these variables. Intercropping had a major positive impact on arthropod abundance, with intercropped cropping system showing about 27% and 69.2% higher than sole strip cropping (SSC) and sole cropping (Ref) plots, respectively. Significant weed suppression was also observed in winter pea treatment when intercropped with winter wheat. Similarly, both intercrop systems showed strong land-use advantages (LER > 1). In winter wheat- winter pea intercrops, where both crops were sown at 50% seeding density, winter pea contributed most (partial LER = 2.40), giving the highest total LER of 3.15. In winter oilseed rape- winter pea intercrops, where both crops were fully seeded, winter pea again dominated (partial LER = 1.95), with a total LER of 2.47. Thus, intercropping improved land-use efficiency, especially for winter wheat-winter pea IC cropping system. In conclusion intercropping increased land-use efficiency and biodiversity mainly in cereal-legume combination without compromising grain yield. Therefore, intercropping is a promising agroecological innovation that increasing biodiversity, weed control, and resource use efficiency while supporting sustainable intensification and enhancing ecological resilience in temperate agroecosystems.