This paper outlines findings for three experiments on the AgResearch Invermay deer farm that quantified soil and water quality via fence-line pacing and wallowing, and water quality in streams draining the farm. Five weeks after winter grazing (28 hinds/ha), fence-line pacing decreased soil macroporosity and saturated hydraulic conductivity, and increased suspended sediment (SS; 0.226 g/100ml), total phosphorus (P) (TP; 2.0 mg/l), mainly as particulate P (up to 90% of TP), and E. coli (3.52 log10 cfu/100ml) concentrations in a simulated overland flow 1 day after grazing had stopped compared to soils from the rest of the paddock (0.148 g/100ml, 0.86 mg/l and 2.86 log10/100ml). Six weeks following a first simulated rainfall event, and without interim grazing, concentrations in the second simulated event had decreased but losses of P, especially in fence-line paced soils, were still high and above recommended limits for surface water quality (TP = 0.033 mg/l). A survey of visible erosion in 6 deer paddocks with topography (2- 10o) yielded a mean erosion rate of 1.08 t/ha/yr (range, 0.41-2.01 t/ha/yr), 43% associated with fence-lines, troughs or gateways and 57% associated with wallows. Data from three waterways indicated that mean values for two sites that drain 100% deer farmed land, exceeded current lowland surface water limits for dissolved (0.01 mg/l) and TP (0.033 mg/l) and ammoniacal-nitrogen (N) (0.021 mg N/l). Limits for E. coli (126 E. coli/100ml) and nitrate-N (0.444 mg N/l) were also exceeded at another site, which drained a wallow. All guideline values were exceeded during storm flow when ephemeral streams, commonly draining wallows, were flowing to permanent waterways. However, loads of P, N and SS were below average for mixed-grazing pasture catchments in New Zealand. This was attributed to a dry year (rainfall
Water and soil quality in an Otago deer farm
