Effects of shelter belts on fence-line pacing of deer and associated impacts on water and soil quality.
Sustainable land use for deer farming requires the maintenance of good soil and water quality, which can be adversely affected by fence-line pacing. This study tested the hypothesis that the absence or presence of shelter belts (one or two) in paddocks decreases fence-line pacing and associated soil and water quality impacts. Soils near the fence line and in the rest of the paddock, in paddocks containing zero, one or two shelter belts, were sampled for bulk density and macroporosity (pores >30 µm diameter). Large intact samples (1×0.2×0.1 m3) were used to generate overland flow via rainfall simulation. The flow was tested for nutrients [phosphorus (P) and nitrogen (N) fractions], suspended sediment (SS), and the faecal indicator bacteria, Escherichia coli. Results showed that bulk density, void volume, SS, particulate P and total P were affected by location (fence line or rest of paddock) but, along with all other measurements except E. coli, were not affected by the number of shelter belts. Thus, the inclusion of shelter had no effect on the concentration of contaminant lost in overland flow or any soil physical or hydrological parameter, but decreased the run-off of E. coli. The lack of contrast between the location of soils can be partly attributed to the soil type (Brown, NZ soil classification, USDA Taxonomy: Typic Fragiudalf), which when compared with past studies was less erosive and lost less P into solution. Other factors may have been different management or the lesser impact of weaners compared with older hinds and stags on soil properties. Although only E. coli concentrations were decreased by the inclusion of shelter, factors such as improved production and animal welfare weigh heavily in favour of installing and maintaining shelter on deer farms. However, the environmental benefit of shelter should be tested in other farms where factors such as slope, soil, climate and farm management may increase the contrast with no shelter.