Epsilon Archive for Student Projects

Abstract

Weed seed banks represent a critical component of agricultural ecosystems, influencing both current weed pressure and the long-term resilience of cropping systems. This study investigated the dynamics of weed seed banks across four contrasting cropping systems (conventional, organic, agroforestry, and perennial (Kernza-based), within the SITES Agroecological Field Experiment (SAFE) at Lönnstorp Research Station, southern Sweden. Soil samples were collected from 16 field plots and analyzed under controlled greenhouse conditions to quantify weed seedling emergence, species richness, diversity, and evenness.
A total of 3,034 weed seedlings belonging to 40 species were identified across all systems. The results showed that cropping systems play a major role in shaping the composition and balance of the weed seed bank. Conventional and organic systems had the highest weed abundance, while perennial plots had the lowest, which reflected the benefit of continuous ground cover and limited soil disturbance. The organic system contained more weed species overall, but it was heavily dominated by a few fast-growing weeds such as Chenopodium album, which reduced the evenness of the community. Agroforestry plots maintained a moderate number of weeds with relatively balanced diversity, suggesting that mixed vegetation and shade can help regulate weed growth.
Overall, the perennial system developed the most stable and evenly distributed weed community, while the conventional and organic systems showed clear trade-offs between productivity and ecological balance. The findings indicate that long-term weed management is not only about reducing weed numbers but also about creating resilient and diverse seed bank communities. The broader implication is that integration, rather than reliance on any single approach, may offer the most viable pathway toward sustainable weed management, balancing productivity, biodiversity, and environmental health.