Plant and soil responses to simulated summer drought in 2013 on Colt Park grassland restoration experiment

Location: Colt Park meadows, Ingleborough National Nature Reserve (latitude 54°12’N, longitude 2°21’W). The two grassland restoration treatments used in this experiment were fertiliser application and seed addition. The drought treatment was superimposed onto these two treatments. All experimental plots were cut for hay on 16 July in 2013. After the hay cut, all experimental plots were grazed by cattle and sheep. Since 1990, half of plots received continued fertiliser application and half receive no fertiliser, with the exception of 2009 and 2010 when fertiliser was not applied. Inorganic fertiliser (NPK 20:10:10; 25kg N ha-1) was applied by hand in spring (21 May in 2013). Seed addition began in 1990 with seed of 19 species being locally collected and commercially bought. The drought treatment had three levels, a) ambient, consisting of no rain-out shelter; b) control shelter, consisting of a rain shelter with holes; c) drought, consisting of a rain-out shelter. Rain-out shelters were in place from 5 June to 10 July 2013. They were constructed of transparent corrugated PVC, 0.8mm thick (Corolux, UK) and were 90cm x 105cm with a height of 38cm-63cm and a slope of 16 degrees.