Influence of soil properties on coastal sandplain grassland establishment on former agricultural fields

The decline in species-rich grasslands across the United States has increased the importance of conservation and restoration efforts to preserve the biodiversity supported by these habitats. Abandoned agricultural fields often provide practical locations for the reestablishment of species-rich grasslands. However, these fields often retain legacies of agriculture both in their soils, which may have higher pH and nitrogen (N) contents than soils that were never farmed, and in their plant communities, which are dominated by non-native species and poor in native seed stock. We considered methods of reversing these legacies to create native-species-rich grassland on former agricultural land. We tested seeding and tilling combined with additions of sulfur (S), carbon (C), Norwater to establish diverse sand plain grassland vegetation on an old field on Martha's Vineyard, Massachusetts. We measured soil pH, extractable nitrate and ammonium, and total and native species richness and native species cover for 5 years after treatment. S additions lowered pH to values typical of never-tilled sandplain ecosystems and increased native species cover, but had no effect on species richness. C, N, and water additions had no significant effects on the soil or vegetation. Seeding and tilling were more effective at restoring native species richness than any soil amendments and indicated a greater importance of biotic factors compared with soil conditions in promoting sandplain vegetation establishment. S amendment accelerated establishment of native species cover for several years but the effect of S additions compared with seeding and tilling alone declined over time.