Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 25, 2008
Publication Date: July 17, 2008
Repository URL: http://hdl.handle.net/10113/19592
Citation: Stone, K.C., Hunt, P.G., Millen, J.A., Johnson, M.H., Matheny, T.A., Vanotti, M.B., Burns, J.C. 2008. Forage subsurface drip irrigation using treated swine wastewater. Transactions of the ASABE 51(2):433-440. Interpretive Summary: In the 1990’s, the eastern United States experienced a rapid expansion of animal production. Along with the increased animal production, large quantities of animal waste were produced. These large quantities of animal waste needed to be utilized or disposed of efficiently and without adversely impacting the environment. To treat the animal waste, industry, government, researchers, producers, and environmentalists worked to together to identify and create new and innovative treatment systems. At one of these innovative treatment systems, we hypothesized that we could utilize the excess treated effluent to irrigate bermudagrass hay using a subsurface drip irrigation system. The subsurface drip irrigation system applied the effluent below the soil surface and can eliminate the spray and drift associated with conventional sprinkler irrigation systems. Furthermore, reducing the spray and drift could also reduce the spread of odors and ammonia volatilization. We installed and evaluated the subsurface drip irrigation system using either commercial fertilizer or effluent from the waste treatment system as fertilizer. In 2004 and 2005, we produced about 6 and 14 metric tons of bermudagrass hay per hector, respectively. The plots fertilized with the treated effluent produced higher hay yields both years. We also measured soil and soil water in the plots and found that neither the commercial or effluent fertilizer adversely affected the soil or water quality. Our results demonstrated that treated effluent can successfully be applied through a subsurface drip irrigation system and efficiently utilize the excess nutrients in an environmentally friendly manner.
Technical Abstract: Animal production in the 1990’s expanded rapidly in the eastern US. This rapid expansion has resulted in large amounts of concentrated animal waste that must be utilized or disposed of in an efficient and environmentally friendly manner. To deal with these large quantities of animal waste, new and innovative treatment systems were pursued. One such treatment system was constructed and tested at a farm in Duplin County, North Carolina. The objectives of this study were to determine the feasibility of using subsurface drip irrigation (SDI) for application of effluent from an innovative swine wastewater treatment system and to evaluate the system impacts on soil and water quality. Effluent from this treatment system was used to irrigate bermudagrass hay using a SDI system. The SDI system consisted of two lateral spacings (0.6 and 1.2 m) installed at 0.3 m below the surface. Irrigation was scheduled to supply either 75 or 100% of the calculated crop evapotranspiration (ET) requirements. The two-year study measured hay yields, hay biomass, soil nutrients, and soil water nutrients. Results from the SDI system indicated no significant differences between the irrigation lateral spacings or scheduling methods. Both commercial fertilizer and effluent from the treatment facility were applied through the SDI system at agronomic nutrient rates to the bermudagrass forage crop. The SDI system was successfully operated for two years applying effluent to supply the nutrient requirements of the bermudagrass hay. The bermudagrass hay production for 2004 and 2005 ranged from 5.65 to 14 Mg/ha. The treatments with treated effluent had significantly higher hay yields and significantly higher nutrient biomass removal rates than the commercial fertilizer treatments and did not adversely impact the soil or water quality.