Location: Dale Bumpers Small Farms Research CenterTitle: Using Google SketchUp to simulate tree row azimuth effects on alley shading Author
|Burner, David - Retired ARS Employee|
|Laughlin, Kent - Alta Planning And Design|
|Boyer, Mark - Louisiana State University|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/24/2017
Publication Date: 11/27/2017
Citation: Burner, D.M., Ashworth, A.J., Laughlin, K.F., Boyer, M.E. 2017. Using Google SketchUp to simulate tree row azimuth effects on alley shading. Agronomy Journal. 110:1-6.
Interpretive Summary: Agroforestry alley cropping practices include designed plantations of tree rows separated by an inter-row alley. Under this practice, trees supply a long-term source of income from sale of wood fiber, and a non-timber alley crop provides short-term revenue. Numerous plantation designs can be applied to landscapes to optimize tree density consistent with landowners’ management objectives. Regardless of design, one consistent factor is that with time and growth, trees cast increasingly long shadows between and within rows. Tree row azimuth is an important plantation design criterion and effect of row azimuth on tree growth and productivity varies with species. Simulation experiments are a useful first step in developing models, given the cost and time needed to establish plantations, and collect and analyze shade data. Therefore, to begin this process, USDA-ARS scientist and University personnel collaborated to determine if Google SketchUp could be used to simulate effect of azimuth orientation on alley illumination between loblolly pine rows. Results suggest simulations could aid in the design and placement of pine plantations in the landscape for agroforestry practices, thereby reducing the time and cost associated with in-field testing at the plantation-scale. This study is of interest to scientists, extension specialists, and agency personnel.
Technical Abstract: Effect of row azimuth on alley crop illumination is difficult to determine empirically. Our objective was to determine if Google SketchUp (Trimble Inc., Sunnyvale, CA) could be used to simulate effect of azimuth orientation on illumination of loblolly pine (Pinus taeda L.) alleys. Simulations were conducted for trees in East-West, North-South, Northeast-Southwest, and Northwest-Southeast azimuth orientations assuming tree size parameters and row spacing of a 14-y-old plantation near Booneville, Arkansas. SketchUp predicted that the East-West azimuth allowed significantly more illumination at the alley surface during April-August compared to other azimuths, and significantly less illumination than other azimuths during October-February. SketchUp could assist the design and placement of pine plantations in the landscape for agroforestry practices, reducing the time and costs associated with in-field testing at plantation-scale.