Impact of Intermittent Clipping on Productivity, Forage Quality and Legume Persistence of Reclaimed Mine Soils

The materials used as plant growth media during surface mine· reclamation are frequently low in available N, P and K and are drought­prone. Legumes are included in reclamation seeding mixtures . because of their symbiotic N2-fixation ability but competition may prevent establishment or reduce persistence. A field study was conducted to test the hypothesis that intermittent clipping of these sites would reduce grass competition and thereby maintain legume stands. In 1990 and· 1991, 4 clipping treatments were imposed, providing intervals of 2, 4; and 6 weeks between harvests. Clipping at the 2- or 4-week intervals gave equal yields that were nearly I t/ha lower than those from the 6- week clipping interval. Crude protein yields did not differ for the different: harvest regimes and averaged 0.7 I/ha, Legume ground cover averaged ! 3.5, 34.4, 43.2, and 30.0% for the uncut, 2-week, 4-week, and 6-week treatments, respectively. Results of this 2-year field study indicate that intermittent clipping improves the contribution of legumes to reclamation mixtures after 2 years.