Study site.
In 2015, the field experiment was set up in a restored grassland site (abandoned from agricultural use in 1996), “De Mossel” (Natuurmonumenten, Ede, The Netherlands, 52° 04´ N, 5° 45´ E). Soils are holtpodzol, sandy loam (94% sand, 4% silt, 2% clay, ~4% organic matter, 5.2 pH, 2.5 mg kg-1 N, 4.0 mg kg-1 P, 16.5 mg kg-1 K) (Jeffery et al. 2017). Average daily temperatures in the area are 16.7 °C in summer months and 1.7 °C in winter months. Average monthly precipitation ranges from 48 to 76 mm (www.climate-data.org).