Limited Protective Effect of Paddock Grids on Horse Trails Compared to Unprotected Trails in a Swiss Field Experiment

ABSTRACT Paddock grids on horse trails are used to protect animals from injuries, but the impact of paddock grids on soil quality is not well documented. In a 15 months experimental field study, we investigated possible protective effects of two types of paddock grids used on paddock trails (referred to as ‘basic’ and ‘reinforced’) on key soil quality indicators in comparison to unprotected trails also used by the horses. These installations of paddock grids were analysed with and without wood chip buffering layers. Horse‐induced soil degradation was measured in all treatments, leading to a significant increase in soil bulk density, decreases in microbial biomass and soil organic carbon content, and smaller changes in water content in response to precipitation and dry phases. The soil of the unprotected trail was particularly affected by the horses, and no recovery in vegetation cover within 7 weeks after removal of the horses was observed. Comparing the two types of paddock grids showed that the soil under the reinforced paddock grid was marginally less compacted compared to the soil under the basic paddock grid. An additional wood chips buffering layer was found to have no additional protective effect. In conclusion, we found no significant difference in the negative impact induced by horses on physical and microbiological parameters of soil quality between trails with and without paddock grids (independent of the type and installation of the paddock grids) during the timespan of this study. However, we found that paddock grids allowed a faster recovery of vegetation cover than unprotected trails after the horses were removed from the trails.