Quality and yield of seven forages grown under partial shading of a simulated silvopastoral system in east TexasThis article is part of a larger document. View the larger document here.
The goal of this project is to evaluate the growth and nutritional characteristics of seven forages, including various warm season native grasses, grown under simulated partial shading (50 percent typical of a loblolly pine silvopastoral system in east Texas. The results are from year two of a three year study. In order to meet the overall objective, individual, slatted shade structures were constructed that simulate the quantity, quality, and overall light regime found beneath loblolly pine stands arranged for silvopasture. The forages selected for the study include ‘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 is a two-way factorial design with forage type randomly assigned to plots, and shade treatment (0 percent, 50 percent) randomly assigned within forage type. Forage produced beneath the slats is 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 in vitro true digestibility (IVTD), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF). Results show that significant differences existed in all parameters (p < 0.0001) due to forage type. Significant differences existed due to shade treatment for all parameters except for ADF (p = 0.1324). Results showed that shade improved forage quality overall. It reduced NDF (p = 0.0399), increased CP (p = 0.0007), and increased digestibility IVTD (p < 0.0001). The study is currently in year two of three. Results are preliminary.