Flower strips as a carbon sequestration measure in temperate croplands

Abstract

Purpose Flower strips have been shown to increase insect biodiversity and improve agricultural yields through increased pollination and pest predation. Less is known about their potential to increase soil organic carbon (SOC). We aimed to investigate the biomass production and SOC sequestration potential of flower strips as a sustainable management option of temperate agricultural soils. Methods 23 flower strips across varying soil types and climatic regions in Germany were sampled for aboveground and belowground peak biomass in order to estimate the annual carbon input to the soil. Those were used as 23 scenarios to model the potential SOC sequestration of the flower strips compared to a business-as-usual scenario for 1533 sites of the German Agricultural Soil Inventory using the RothC model. Results On average, flower strips sequestered 0.48 ± 0.36 Mg C ha−1 year−1 in the initial 20-year period after establishment. Converting 1 % of the total German cropland area into flower strips would thus lead to a mitigation of 0.24 Tg CO2 year−1, which equals 0.4 % of current agricultural greenhouse gas emissions in Germany. We found a negative correlation between C sequestration rate and the number of plant species in the flower strips, mainly related to grasses outcompeting herbaceous species. Conclusion Flower strips are one overlooked option for increasing SOC stocks of croplands that has multiple benefits for agro-ecosystems. However, within a flower strip it might not be possible to maximise both plant biodiversity and SOC sequestration.

Flower Strips as an Ecological Tool to Strengthen the Environmental Balance of Fields: Case Study of a National Park Zone in Western Poland

“…Harbo et al [41] indicate that flower strips not only increase biodiversity, but also reduce greenhouse gas emissions through increased carbon sequestration. The authors found that in the initial 20-year period after establishment, flower strips absorbed on average 0.48 ± 0.36 Mg C ha −1 year −1 , concluding that the conversion of 1% of the total area of arable land in Germany into flower strips would lead to a reduction in emissions of 0.24 Tg CO 2 year −1 , which equals 0.4% of the current greenhouse gas emissions in this country.…”