The effects of treading by dairy cows on soil properties and herbage production for three white clover-based grazing systems on a clay loam soil.

White clover can reduce fertilizer-N requirements, improve sward nutritive value and increase environmental sustainability of grazed grasslands. Results of previous experiments in glasshouse conditions and on mown plots have suggested that white clover may be more susceptible than perennial ryegrass to treading damage on wet soils. However, this phenomenon has not been investigated under actual grazing conditions. This experiment examined the effects of treading on clover content, herbage production and soil properties within three clover-based grazing systems on a wet soil in Ireland for 1 year. Treading resulted in soil compaction, as evidenced by increased soil bulk density ( P < 0·001) and reductions in the proportion of large (air-filled) soil pores ( P < 0·001). Treading reduced annual herbage production of both grass and white clover by similar amounts 0·59 and 0·45 t ha−1 respectively ( P < 0·001). Treading reduced the sward clover content in June ( P < 0·01) but had no effect on annual clover content, clover stolon mass or clover content at the end of the experiment. Therefore, there was little evidence that white clover is more susceptible to treading damage than perennial ryegrass under grazing conditions on wet soils. [ABSTRACT FROM AUTHOR]