Dry matter yield and herbage quality of field margin vegetation as a function of vegetation development and management regime

Abstract

Dry matter (DM] yield and herbage quality of unfertilized mown field margin strips were studied during early succession in a field experiment over a period of three years. The experiment aimed to maximize botanical diversity and was conducted at two different locations with contrasting soil type and comprised four vegetation types (spontaneously regenerated versus sown vegetation) and three herbage removal strategies (herbage left versus herbage removed). The experimental factors investigated were location, vegetation and herbage removal. Margin strips were mown twice a year with a late first cut around 15 June and a regrowth cut around 15 September to meet nature conservation objectives. Average DM yield over the first three years was not significantly affected by herbage removal but increased significantly over time, irrespective of vegetation or herbage removal. Initially, sown margin strips significantly outyielded unsown margin strips, but differences in DM yield converged over time. The mid-June cut yielded significantly more than the regrowth cut but its herbage quality was significantly lower. Herbage from the unsown margin strip had a significantly better forage quality than herbage from sown margin strips. Forage quality decreased over time, irrespective of location or vegetation. Changes over time in DM yield and quality were attributed to changes in species composition. The herbage quality of field margins was lower than the herbage quality of intensively managed grassland, limiting its use in rations for highly productive livestock.