干旱区生态环境知识资源中心

Large areas of soil corer across the desert southwestern United States hate been highly impacted by military training arid require revegetation. Revegetation efforts commonly optimize growing conditions by increasing plant-available water through irrigation. Simulations of soil water balance were conducted using the Simultaneous Heat and Water (SHAW) model to examine how key environmental factors, including precipitation, soil properties, and irrigation strategies, control soil water balance arid plant-available water. Simulations include surface and subsurface irrigation of 7 mm (water) applied monthly and 21 and 28 mm applied three times a year. Results indicate that any augmentation of soil water provides for an increase in transpiration relative to precipitation between about 50 to 250%. Subsurface irrigation provided a slightly greater increase in transpiration relative to surface irrigation, except for surface irrigation at monthly, intervals, which provided the lowest increase in simulated transpiration, because most of the applied water is lost to evaporation. Results indicate that surface and subsurface irrigation three threes annually and attiring tire spring and summer months provides the greatest effective benefit. Simulations also indicate that use of bark chips as a surface mulch will decrease plant-available water, whereas surface mulch of a light colored gravel will enhance moisture retention. Construction of catchments will also increase soil grater where surface runoff occurs. Application of numerical models for evaluating soil crater balance provide a cost-effective method for assessing techniques designed to enhance the availability of plant water required for revegetation efforts.