Epsilon Archive for Student Projects

Abstract

Producing enough food to meet the needs of the growing global population is becoming increasingly challenging. Among the factors limiting food production, weeds are a major contributor, causing 34% of global yield loss. Effective weed management requires identifying the weed seed bank, as it serves as the primary source for future weed growth. A significant amount of research has examined the relationships between crop biomass and weed growth, the influence of crop rotations on weed seed density, and the impact of different cropping systems on weed community composition. However, a gap remains in understanding the effects of diversified organic crop rotations on the characteristics of weed seed banks. Investigating this aspect is essential for improving sustainable weed management practices, particularly within organic farming systems
This study examined the composition of the weed seed bank and the effects of different intercropping treatments on weed abundance, species richness, diversity, and evenness in an organic field experiment in Alnarp, Sweden. A total of 996 individual weeds, representing 24 species, were identified from 50 soil samples. The dominant weed species were Veronica arvensis, Sonchus asper, Stellaria media, Matricaria perforata, and Chenopodium album.
Oat intercropping increased species richness and weed diversity compared to oat sole cropping. However, intercropping oilseed rape with faba bean and intercropping pea with malting barley had no significant effects on species richness or diversity, and none of the intercropping treatments impacted weed evenness. An analysis was conducted to examine the relationship between weed biomass observed from the previous year and the weed seed bank. Results indicated that weed biomass had no significant impact on the composition of the weed seed bank in the current experiment. These findings suggest that while intercropping can influence weed diversity in specific crops, it does not significantly affect overall weed abundance, evenness, or seed bank dynamics. Extreme weather conditions in recent years could have significant disrupt the timing of weed control, which has become an increasing challenge in organic farming. Increasing support from authorities such as Länsstyrelsen Skåne, HIR Skåne and Jordbruksverket newsletters can offer farmers valuable guidance to enhance their knowledge and practices in organic weed management.