Study

Restoration of species-rich grasslands on ex-arable land: seed addition outweighs soil fertility reduction

  • Published source details Kardol P., Wal A.V., Bezemer T.M., Boer W., Duyts H., Holtkamp R. & Putten W.H.V. (2008) Restoration of species-rich grasslands on ex-arable land: seed addition outweighs soil fertility reduction. Biological Conservation, 141, 2208-2217.

Summary

Within a European context, on abandoned agricultural land targeted for semi-natural species-rich grassland creation, high soil fertility and limited natural plant dispersal ability are considered main constraints to restoration success. Often soil fertility reduction is deemed necessary for establishment of desired plant communities. A 3-year experiment was conducted on an ex-arable sandy soil site at the village of Assel, Gelderland (52°21′N, 5°82′E), the Netherlands. Effects of soil fertility manipulations and sowing native mid-successional plant species on plant community development and soil biological properties were assessed.

After abandonment in 2002, in May 2004 four blocks (5 m apart) each containing eight plots (4 x 4 m), were established. Treatments applied were: control, wheat Triticum spp. straw addition, birch Betula pendula wood chip addition (to incorporate nutrients), and top soil removal (to reduce nutrients). Treatments were applied with or without sowing of characteristic mid-successional perennial species of abandoned cropland in the region: a mix of four grasses (common bent Agrostis capillaris, sweet vernal Anthoxanthum odoratum, quaking grass Briza media, sheep’s fescue Festuca ovina; 500 seeds/m2) and four forbs (yarrow Achillea millefolium, cat’s-ear Hypochaeris radicata, ribwort plantain Plantago lanceolata, common sorrel Rumex acetosella; 150 seeds/m2).

In July/August 2004, 2005 and 2006, percentage cover of each vascular plant species was recorded (inner 2 x 2 m of plot), and standing biomass determined by clipping subplots. In May 2004, 2005 and 2006, soil samples were collected, soil parameters were analysed,  and bacterial and nematode abundance and root biomass (2005 and 2006) determined.
 
A microcosm study was also undertaken to assess short-term effects of soil fertility reduction on biomass production of the sown species.

Contrary to expectations establishment of the sown plant species was better without soil fertility reduction (i.e. topsoil removal). Whilst the sown species all established, topsoil removal reduced establishment success (reduced biomass) and created a ‘desert-like environment’, although it effectively suppressed arable weeds. Adding straw or wood resulted in short-term plant biomass reduction (suggesting decreased available nutrients).
 
Topsoil removal also greatly reduced bacteria and nematode abundance, and fungal biomass, but straw and wood addition had little effect. On average, in top soil removal plots bacterial numbers were 2-fold and fungal biomass was 14-fold lower.
 
 

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust