Table 1. Statistical results ^a of two-way ANOVAs of the initial soil mixture properties ^b.

	WHC (48 h)		Nmin_initial (KCl)		Nmin_leached		%Nleached.c
Factor	F	p	F	P	F	p	F	p
Compost	336.8	<0.001	3327.2	<0.001	773.3	<0.001	32.7 (19.8)	<0.001
Biochar	626.0	<0.001	919.8	<0.001	523.3	<0.001	128.7 (93.4)	<0.001
Comp x BC	10.7	<0.001	696.5	<0.001	38.3	<0.001	10.5 (6.5)	<0.003

^aResults correspond to Figure 1 and Supplementary Figure S3.

^bAbbreviations: WHC, water holding capacity after 48 hours (Supplementary Fig. S3); N_{min_initial} (KCl), initially extractable amount of mineral N (Fig. 1A); N_{min_leached}, amount of mineral N drained with the WHC determination (Fig. 1B); %N_leached, amount of mineral N leached (WHC) in percent of the initial, KCl-detectable amount of N_min (Fig. 1B, large blue dots).

^cF values in brackets refer to the diamonds in Fig. 1B (nitrate loading of BC_comp not considered).