18th Congress of the European Society for Agronomy

Effect of sown flower margins on pollinators, crop productivity and soil properties in intensive agriculture

Not scheduled

15m

Les Dortoirs (1st floor) (The Couvent des Jacobins)

Poster Synergies between disciplines Poster session #2

Speaker

Lina Šarūnaitė (Lithuanian Research Centre for Agriculture and Forestry)

Description

1. Introduction
   To halt the loss of biodiversity in agricultural landscapes, the European Union's Common Agricultural Policy promotes the implementation of practices that benefit the climate and the environment - various non-productive activities. One of them is the flowering plant margins on field edges. Multifunctionality of flower margins is very different depending on landscape composition, management regime, location, and organism groups etc. Therefore, a detailed assessment of their benefits and risks is required. The aim of this study was to determine the effect of differently sown flower field margins on pollinators, crop productivity and soil properties.

2. Materials, methods
   The experiment was carried out during 2013–2018 at two experimental sites Joniškėlis (JON) and Akademija (AKD) of Lithuanian Research Centre for Agriculture and Forestry. The floral sward strips were established on the edges of intensive farming land (field size > 5 ha). The strip were seeded with four plant mixtures: 1) perennial grasses, control (PGS): Festuca arundinacea Schreb., Festuca pratensis Huds., Festuca rubra L., Phleum pratense L., Dactylis glomerata L., Agrostis capillaris L. etc.; 2) perennial legumes (PLS): Trifolium pratense and repens L., Onobrychis viciifolia Scop., Medicago sativa L., Lotus pedunculatus Cav. etc.; 3) annual flower plants (AFP): Helianthus annuus L., Fagopyrum esculentum Moench, Borago officinalis L., Sinapis alba L., Phacelia tanacetifolia L., Linum usitatissimum L., Lupinus luteus L., Melilotus albus L., Trifolium resupinatum L. etc.; 4) natural grassland with native plant species (NGS): the base cover: Poa palustris L., Poa compressa L., Corynephorus canescens L. etc.; flowering meadow plants: Trifolium rubens L., Medicago lupulina L., Vicia cracca L. etc., Centaurea jacea L., Agrimonia eupatoria L. etc.

3. Results

The highest value of the floristic index was found in the AFP and PLS field margins. The AFP margin was characterized by an earlier onset and a longer duration of flowering. The following plant species started flowering earliest there: Linum usitatissimum L., Fagopyrum esculentum Moench, Sinapis alba L., Phacelia tanacetifolia Benth; Melilotus officinalis (L.) Pall. flowered longest and Helianthus annuus L. In the NGS margin native plant species flowered profusely: Medicago lupulina L., Achillea millefolium L., Galium boreale and mollugo L., Hypericum perforatum L, Centaurea jacea L., Heracleum sibiricum L., Plantago laceolata L. In Joniškėlis, the total number of pollinators in the flower margins was 33% lower than in the flower margins compared to Akademija. Most of the pollinators were representatives of the following orders: Hymenoptera, Diptera and Coleoptera. The two areas differed considerably in the pollinators number of the order Hymenoptera, which was lower in the more intensive farming area of Joniškėlis. When comparing the margins of different composition, it was found that the highest number of pollinators was found in the AFP and NGS strips. During the five-year period, the plants of the flowering margins due to their strong and rich root system, enriched the soil with organic matter (especially PGS and NGS) and improved the top layer and sub layer soil properties at the field margins. The response to crop yield was not consistent.

1. Discussion
   Creating field margins helps to maintain populations of wild bees and other pollinator insects and ensure their viability (Königslöw et al., 2021). In our studies, the diversity of species composition and phenological development of annual flowering plants attracted more pollinators. The abundance of flowers is a key factor for the diversity of wild bees. Species belong to the Hymenoptera and Diptera families are considered as a very efficient pollinators (Ouvrard et al., 2018). In order to preserve native, rarer plant species, these species are included in flowering margins plant compositions (Königslöw et al., 2021). Flower field margins are for increasing SOC stocks, optimize pest abundance, that has multiple benefits for agroecosystems (Harbo et al., 2023).

2. References
   Harbo L.S., Schulz G., Heinemann, H. et al. 2023. Flower strips as a carbon sequestration measure in temperate croplands. Plant Soil, 482, 647–663.
   Königslöw V., Mupepele A.Ch., Klein A.M. 2021. Overlooked jewels: Existing habitat patches complement sown flower strips to conserve pollinators. Biological Conservation, 261:109263.
   Ouvrard P., Transon J., Jacquemart A.L. 2018. Flower-strip agri-environment schemes provide diverse and valuable summer flower resources for pollinating insects. Biodivers Conserv, 27:2193–2216.