Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2008
Publication Date: May 15, 2008
Citation: Read, J.J., Fairbrother, T.E. 2008. Effects of harvest management on bermudagrass yield and nutrient utilization in a swine-effluent spray field [abstract]. Proceedings Mississippi Water Resources Conference. p. 52. Technical Abstract: Nutrient management plans for swine manure often include the use of the anaerobic-lagoon effluent on bermudagrass [Cynodon dactylon (L.) Pers.] hay fields. Harvesting bermudagrass hay has potential to provide both high quality forage for livestock and a means to remove large quantities of nutrients, particularly N, P, Cu and Zn, from the site. Field plot research was conducted on a commercial swine farm in 2001-2003 to compare uptake of N and P by common bermudagrass under different harvest management schemes. A center-pivot system applied 15 cm-ha swine effluent during April–October (which is equivalent to 520 kg/ha N and 110 kg/ha P). After an initial harvest in early May, the plots were harvested at 4, 6, 8, 10, and 12 wk intervals and at heights of 3 and 9 cm from the soil surface. Maximum values for P uptake were obtained with the 10-wk interval in 2001 and the 6-wk interval in 2002 and 2003. The year x height interaction was significant (P<0.05); however, harvesting at 3-cm height consistently increased P uptake by about 18% in 2001, 28% in 2002, and 29% in 2003, as compared to 9-cm height. Results provide management options for swine-effluent spray fields. If the goal is high-quality hay, bermudagrass should be cut frequently (< 5-wk) and as tall as practical to harvest more leaves. If the goal is to maximize nutrient utilization, bermudagrass should be cut at 6-10 wk intervals and as close to the ground as possible to obtain high biomass yield.