Ecological and economic optimization of methods for enhancing fringe communities in productive agricultural landscapes (ProSaum)

Project priorities

The project analyzed implementation deficits regarding the use of native species in the enhancement of field margins and hedgerows and tested practical methods for establishing flower-rich, site-adapted, perennial field margins and hedgerows on productive sites. To this end, suitable seed mixtures were developed for aesthetically appealing field margins that require little maintenance and can be used both at the edges of agricultural land and for greening green spaces, paths, and roadsides.

Project region

Bernburg, Osnabrück

Further project details

• Attempt to establish a species-rich field margin

  At the edge of the Ochsendorf trial field on the Strenzfeld campus, a block trial with six variants and five replicates was set up at the beginning of October 2010. For the sowing variants, the existing species-poor grass fringe was destroyed by tilling once or three times. On October 7, 2010, the tilled areas were seeded with 49 native, perennial fringe and meadow species (e.g., field scabious, colorful crown vetch, dyer’s chamomile, medicinal stonecrop, St. John’s wort, Carthusian pink, daisy, agrimony, globeflower, meadow bellflower, meadow sage, wild mallow, whorled speedwell). The sowing rate was 2 g/m² (approx. 2000 seeds/m²). After sowing, the areas were rolled by hand with a smooth roller.

  The original vegetation was preserved on two variants; these areas were mowed once (early October) and three times (early June, mid-July, early October) in 2011. The tilled and seeded areas were mulched in early June 2011 and mowed at the end of August 2011 as part of development maintenance. Since 2012, half of the areas have been mowed in early summer (mid-June) and the other half in late summer (early September), and the biomass has been removed.

  At the end of September 2010, Osnabrück University of Applied Sciences in Wallenhorst (Lower Saxony) carried out a similar experiment with 37 native species.

• Ergebnisse

  At the block site in Strenzfeld, 86% of the seeded species could be detected by summer 2011 and 100% from summer 2012 to 2014. In 2014, the average coverage of the seeded species was significantly higher on the early mowed areas than on the late mowed areas. In contrast, the average number of species has shown only minor differences so far. Three rounds of tilling/cultivating led to significantly higher establishment rates in the first few years compared to a single round of soil disturbance.

  The experiments show that species-poor, grass-dominated field margins can be transformed into species-rich and flower-rich stands through intensive soil disturbance and subsequent sowing with regional wild plant seeds, provided that appropriate development maintenance is carried out in the first year (2-3 maintenance cuts). Early mowing on nutrient-rich black soil areas led to higher coverage of target species and lower grass coverage. A combination of early and late mowing proved to be particularly advantageous in the project. While the areas mowed in June show lush flowering in early and late summer, the seeded species on the areas mowed in September flower in midsummer. Due to the decline in coverage of the seeded species and the gradual increase in competitive grasses on the September mowing variants, it is to be expected that the diversity of flowers on these variants will also gradually decline in midsummer in the following years. Therefore, alternating early and late mowing is recommended on nutrient-rich areas. The success of the measures will be monitored in the coming years through vegetation monitoring.

  

  

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• Conclusions for the creation of field margins and field borders in practice

  The results of the studies provided important insights for the planning, creation, and maintenance of wild plant borders and field margins. A detailed description can also be found in Kirmer et al. (2019).

  Soil preparation: When upgrading grass areas, the more thoroughly the turf is destroyed, the more successful the establishment of the seed species will be. The soil can be tilled by milling, cultivating, or plowing. Subsequently, a fine seedbed should be prepared (e.g., by harrowing).

  Sowing time: The best time for sowing is between the end of August and mid-September, preferably immediately before wet weather. Alternatively, sowing can also take place between the beginning of March and mid-April, although this can be problematic in regions with pronounced spring drought. Seeds from wild plants need at least 2-3 weeks of continuous moisture to germinate.

  Sowing method: Sowing can be done mechanically, e.g., with seed drills; the seeds should only be placed on the surface (most wild plants are light germinators). After sowing, the area should be rolled to ensure that the seeds are in contact with the soil.

  Sowing density: The recommended sowing density is max. 2 g/m². To ensure even distribution of the species across the area, the seeds should be mixed with a filler (e.g., grit) to achieve a density of 10-20 g/m².

  Development maintenance (1st year): Unwanted species (e.g., goosefoot, chickweed) can be suppressed by 2-3 maintenance cuts at a height of approx. 10-15 cm before or at the beginning of flowering; the stand is then usually knee-high. If there is a risk of drying out and moderate biomass production, the mown material can remain on the area as protection against evaporation. If growth is very lush, it should be removed. If problem species (e.g., burdock, thistle, creeping thistle) or invasive neophytes occur, additional measures (e.g., mowing, digging out) must be taken. It is important to intervene in good time, i.e., at the bud stage.

  Follow-up maintenance (from the second year onwards): In nutrient-rich locations, mowing with removal of biomass in early summer is particularly recommended. However, as mowing in sections is particularly beneficial for insects, half should be mowed between mid-May and mid-June and the other half 8-10 weeks later (end of July to mid-August). On very nutrient-poor areas, one half can also be left unmowed, whereby the sections should be mowed alternately each year to prevent the unmowed areas from becoming overgrown with grass.

  

  

• Materials on the topic of “More biodiversity in agricultural landscapes”

  • Project: Biodiversity Management Plan with extensive information on measures to promote biodiversity in agriculture
  • Action sheets for biodiversity-promoting measures in agricultural landscapes (as of April 2021)
    • Field margins and field boundaries
    • Perennial flower strips
    • Annual flower strips
    • Buffer strip
    • wildflower strips
    • woodland structures
    • Skylark plot
    • Measures for upgrading the farmstead
    • Biodiversity corridors in vineyards

  • Praxisleitfaden zur Etablierung und Aufwertung von Säumen und Feldraine (2. Auflage 2019)
  • Hinweise zur erfolgreichen Anlage und Pflege mehrjähriger Blühstreifen und Blühflächen mit gebietseigenen Wildarten
  • Poster zu “Betriebsplan Biodiversität – ein Planungs- und Beratungstool für Landwirtschaftsbetriebe” (Stand Juni 2018)
  • Poster zu “Etablierung und Pflege artenreicher Feldraine auf produktiven Standorten im Mitteldeutschen Trockengebiet” (Stand Juni 2018)
  • Poster zu “Effekte mehrjähriger Wildpflanzen-Blühstreifen auf die floristische und avifaunistische Vielfalt in der Agrarlandschaft Sachsen-Anhalts” (Stand Juni 2018)

  

  

  

  

  

  

  

  

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