One of the major challenges for irrigated agricultural production in arid and semi-arid regions like the Great Basin is increasing salt content of soil as water evaporates and leaves salts behind in the soil. Higher salt levels reduce crop yields and can even remove lands from production. Farmers can delay soil salinization by periodically flushing salts from the soil, but this practice requires large amounts of water and can result in salt-contaminated drainage water that pollutes nearby surface waters.
Halophytes, or plants that grow in saline soil or water environments, could be cultivated on saline lands for livestock fodder or human consumption, to provide biofuel for bioenergy production, and to remove salts from the soil to maintain agricultural production of conventional crops. Halophytes may also help reduce salt input to nearby water bodies, thereby improving environmental quality.
As the first phase in a long-range project that investigates the potential for halophytes to improve agricultural production and environmental quality of irrigated lands, we will augment two widely-used USDA agricultural models, the Soil and Water Assessment Tool (SWAT) and the Agricultural Policy/Environmental Extended (APEX) model, to model halophytic plants and salt movement through the soil-plant-water environment.
Because APEX and SWAT are crop growth models, the models can be used to examine how much biomass can be produced over different time horizons and the amount of salt that could be removed from the landscape using halophytes. The project’s long-term goal is to assess the potential for halophytic plants to be used as an economic resource via food for humans or livestock, biofuel production, and by maintaining agricultural production of conventional crops on saline lands.
If modeling results indicate this approach is feasible, we then plan to design specific studies to verify the viability of halophytes to provide an economically and environmentally valuable crop in Nevada.