Fertilizer effects on establishment of two seed mixtures on mined land in southeastern Montana

ABSTRACT:

Nitrogen and phosphorus fertilizer, applied in the first year of a six-year evaluation of plant establishment on strip-mined land at Colstrip, Montana, had no effect on long-term survival of plants seeded in 4-species and 16-species mixtures. However, fertilizer application significantly (P .05) increased above-ground biomass. The number of native plant species established was substantially higher on plots seeded with the 16-species mixture than on plots seeded with a 4-species mixture. Despite the proximity of native range, nonseeded native species were almost nonexistent on plots seeded with both mixtures. This indicates that natural succession is a slow process on mined lands at Colstrip. Critana thickspike wheatgrass (Agropyron dasystachyum), lodorm green needle-grass (Stipa viridula), and fourwing saltbush (Atriplex canescens) are native species that appear suited for mined-land plantings in the Northern Plains. Fairway crested wheat-grass (Agropyron cristatum), while easy to establish, may be too competitive in mixtures with native species. Two legumes, ranger alfalfa (Medicago sativa) and lutana cicer milk-vetch (Astragalus cicer), showed considerable potential for reseeding mined lands in the area.