Fig. 7. The spatial distribution of soil NH₄–N (mg kg^–1) with depth and distance along a drip line (A and B) and from a dripper to the mid-row (A–C) in drip-irrigated effluent treatments with and without harvest residues at the Albany Effluent Irrigation Treatment Farm, Albany, Western Australia. Treatments with harvest residue have a layer above the soil surface to represent NH₄–N in the harvest residue.