Converting agricultural land into natural habitat
The Louis Bolk Institute runs various projects aimed at converting former agricultural land to nature areas. Nature conservation organisations such as Staatsbosbeheer and Natuurmonumenten would like to increase the biodiversity of these areas. However, the high soil phosphorus levels – a legacy of agricultural fertilizer use – inhibit the development of species-rich plant communities. Therefore the specific aim of these projects is to reduce the phosphorus levels in these soils.
Reducing soil phosphorus levels through grass-clover
Researchers of the Louis Bolk Institute have developed a new method to remove excess phosphorus from former agricultural soils: growing grass-clover combined with regular mowing and removal of the cuttings. This system is particularly effective when the grass-clover is fertilised with potash. In the latter case the feed value of the cuttings is also higher: a win-win situation for both livestock farmers and nature conservation organisations. Field results of this promising method were recently published in the Journal of Environmental Quality (March 2016).
Field trials in various provinces
The first large-scale field trial was conducted on 60 ha in the Drunense Duinen nature area in the province of Noord-Brabant. We conducted similar projects in other provinces, including Overijssel, Drenthe and Gelderland. The projects are funded by provincial governments, the Government Service for Land and Water Management DLG, the Steering Group Agricultural Innovation Brabant, as well as water boards and landscape conservation organisations.
The Louis Bolk Institute has carried out research on this thema for more than ten years and projects are carried out in close collaboration with various private research and consultancy organisations (Delphy, B-WARE and Smeding Advies).