Fig. 1. Differentiation of mineral nitrogen (N_min) in different zones of use (as indicated by Zones 1–4) in the free-run soils of conventional free-range (F) and organic (O) broiler farms, 0- to 90-cm sampling depth (O2: 0–30 cm). Significant differences in the 0- to 30-cm soil depth at a particular date are marked with letters. Different scales are due to different orders of magnitude.