ARS | Publication request: Bermudagrass yield response to irrigation and nitrogen in the southeastern Coastal Plain

Submitted to: International Irrigation Show
Publication Type: Proceedings
Publication Acceptance Date: October 5, 2012
Publication Date: November 2, 2012
Citation: Stone, K.C., Bauer, P.J., Andrae, J. 2012. Bermudagrass yield response to irrigation and nitrogen in the southeastern Coastal Plain. In: Proceedings of the Irrigation Association International Irrigation Technical Conference, November 2-6, 2012, Orlando, Florida. 10 p. CDROM.

Technical Abstract: In the southeastern region of the US, the cattle industry has a critical need for sustainable hay production. However, production is threatened by frequent short-term regional drought that can be mitigated by properly managed irrigation. In this study on Tifton 85 bermudagrass, irrigation management, nitrogen fertility levels, and harvest interval were evaluated for their impact on hay quality and yield. The optimal irrigation rate (100%) was set to maintain soil water potentials above -30 kilopascals. The reduced irrigation treatments received water in rates of 0, 33, and 66% of the 100% irrigation rate. In addition, each irrigation treatment had nitrogen rates of 168, 336, and 504 kilograms of nitrogen per hectare. The irrigation and nitrogen treatments were harvested at 4- or 8-week intervals. Over all harvests, nitrogen significantly increased bermudagrass hay yield. When irrigation was required, it significantly increased hay yields and hay yields increased linearly with increasing irrigation rate. The 4-week harvest interval was more responsive to irrigation. A linear relationship was observed between non-irrigated bermudagrass hay yields and average soil water potential. As soil moisture was depleted, non-irrigated hay yields decreased 31 kilograms of nitrogen per hectare. Thus, irrigation management should be critically assessed for its potential role in sustaining hay production in the southeastern Coastal Plain.