data_poxc.csv
Soil permanganate-oxidizable carbon (POXC) from soil samples (-20 cm depth) for 2018, 2019 and 2020.

   Date				Date format = yyyy-mm-dd

   Days				Days after the start of the experiment.

   Treatment			Unfertilized control (NON); mineral fertilized control (MIN); cattle slurry (SLU); 
				agricultural slurry from an on-farm biogas plant (SLA) and amended with biochar (SLA+) 
				and liquid digestate from a non-agricultural biogas plant (LID); fertilizer application 
				rate for all fertilizer treatments (excludes NON) = 140 [kg N ha^-1].

   Replicate			Plots of 9 m x 18 m were arranged in a split-plot design and each treatment was replicated four times.

   Crop				Crop sequence: maize = silage maize (Zea mays L.), wheat = winter wheat (Triticum aestivum L.), 
				barley = winter barley (Hordeum vulgare L.,  grass = forage grass mixture (Lolium hybridum, 
				Lolium perenne, Festuca perennis and Festuca pratensis). Yellow mustard (Sinapis alba L.) as an 
				intercrop in between wheat harvest and barley sowing.

   POXC				Permanganate-oxidizable carbon (POXC) [mg/(kg dry soil)]; Measured according to: Weil, R., Stine, M., 
				Gruver, J., and Samson-Liebig, S. (2003). Estimating active carbon for soil quality assessment: 
				A simplified method for laboratory and field use. American Journal of Alternative Agriculture, 18:3–17.
				NA = soil sample has been lost.