Three experiments were conducted to examine restoration of disturbed land in Arizona. The first experiment attempted to revegetate abandoned farmland by direct seeding native seeds and using various soil preparation techniques, amendments, and weeding of Salsola iberica. Only irrigation and weeding had a significant effect on seed germination and canopy cover. Irrigation increased plant cover on plots, but weeds dominated the cover. A seedbank study conducted near the end of the second growing season found the soil was dominated by weeds and contained few viable native seeds. The results illustrate the difficulty of establishing native plants on abandoned desert farmland due to the dominance of weedy species, the presence of salts in the soil, and the lack of adequate soil moisture.The second experiment, a lysimeter study, tested the efficacy of different evapotranspiration (ET) soil cover designs for stabilization of acidic copper mine tailing piles. The study evaluated the effectiveness of capillary barriers (CB) to contain the waste found in tailings and different plants to revegetate the piles. The ET covers reduced infiltration of water into tailings. Copper concentrations increased significantly in plant tissue grown on the ET covers compared to plants grown in the greenhouse. Plants did not exhibit signs of phytotoxicity and concentrations were below levels toxic to all domestic animals except sheep. The CB did not reduce water infiltration into the tailings or upward migration of copper into the soil cover. Vegetation is vital to an effective ET cover. A mix of transplanted shrubs and seeded grasses and forbs establish long-term, sustainable vegetation.The third experiment examined the influence of biosolids on the bacterial communities within mine tailings by bacterial counts and bacterial diversity. The diversity of neutral copper mine tailings two weeks after biosolid application was compared with that of desert soil via cloning and sequencing of PCR amplified community 16S rRNA. Culturable heterotrophic plate counts (HPC) increased following biosolid addition. Total direct counts exceeded HPC by approximately two orders of magnitude. Overall, biosolid-amended tailings contained large numbers of bacteria diverse in nature and with many of the traits of normal desert soil bacterial communities.

Energy crops may present an opportunity to reduce Nova Scotia’s Greenhouse Gas emissions by offsetting fossil fuel use and provide economic benefits for farmers. They have also received government policy support. To investigate this opportunity, I conduct a partial social cost-benefit analysis using non-equity weighted monetary valuation of growing switchgrass on inactive and underused farmland in Nova Scotia for local residential heating. The private net benefit for farmers, processors and consumers is estimated between $24.9 million and $209.9 million. I estimate that the external net benefit to society from the potential reduction in GHG emissions (at $50/tonne CO2E) ranges from $11.3 million to $72.2 million. This must be taken with caution as the analysis does not account for the entire ecological footprint of the project. While a net benefit to society is suggested, the paper also points to a need for more research surrounding the life-cycle emissions of energy crops.