Quality and Yield Responses of Seven Warm Season Forage Grasses to Partial Shading in a Simulated Silvopasture in East Texas

The goal of this project was to evaluate growth and nutritional characteristics of seven forages, including various warm season native grasses, grown under simulated partial shading (50%) typical of a loblolly pine silvopastoral system in East Texas. In order to meet the overall objective, slatted shade structures were constructed that simulated the quantity, quality, and overall light regime found beneath loblolly pine stands arranged for silvopasture. The forages selected for the study included ‘Tifton 9’ bahiagrass (Paspalum notatum), ‘Tifton 85’ bermudagrass (Cynodon dactylon), ‘Alamo’ switchgrass (Panicum virgatum), ‘Kaw’ Big Bluestem (Andropogon gerardii), ‘Americus’ Indiangrass (Sorghastrum nutans), ‘Harrison’ Florida Paspalum (Paspalum floridanum), and Nacogdoches Eastern gamagrass (Tripsacum dactyloides). The experimental design was a two-way factorial design with forage type randomly assigned to plots, and shade treatment (0%, 50%) randomly assigned within forage type. Forage produced was managed to simulate intensive grazing, with recognition of minimum and optimal grazing heights based on forage type. Data is presented on dry matter yield, as well as several nutritional parameters including mineral composition, in vitro true digestibility (IVTD), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HEMI), and total digestible nutrients (TDN). Light was analyzed for quality and quantity in full sun, beneath loblolly, and under the shade structures in this study, and is reported. Soil parameters were also analyzed, and results indicated that there is potential for improvement in soil quality in a silvopasture, relative to conventional open pastures, and that shade favorably moderated soil temperature in the plots