|Canady, N - PURDUE UNIVERSITY|
Submitted to: ASAE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: October 1, 2004
Publication Date: October 15, 2004
Citation: Canady, N.H., Flanagan, D.C. 2004. Use of polyacrylamide to reduce runoff, soil loss and nutrient loss under lagoon effluent sprinkler irrigation. ASAE Annual International Meeting. Paper No. 04-2085. p. 12. Technical Abstract: Land application of wastewater generated at livestock production facilities has the potential to create serious water quality problems in water bodies adjacent to and downstream from agricultural land. Wastewater application can greatly increase nutrients available for transport in runoff and infiltration. Also, erosion potential is enlarged as storm runoff levels increase because of sealing of the soil surface due to the presence of particulate matter and dispersive ions such as sodium in the wastewater. Polyacrylamide, or PAM, is a soil amendment that has been shown in several studies to significantly reduce erosion induced by rainfall and irrigation. It has also been shown effective as a barrier against the surface transport of nutrients and pathogens from waste contaminated areas. This study was conducted in order to investigate erosion and nutrient transport in soils receiving wastewater containing dissolved PAM, simulating a situation in which a natural storm occurs on a field a short time after surface application of a lagoon effluent. Soil was packed into boxes of length 45 cm and width 31 cm to a depth of 16 cm. Swine wastewater from a third stage aerobic lagoon was mixed with PAM and then applied to the soil with an application depth of 0.7 cm, twice over the course of 2 days. On the third day, a rainfall simulator was used to apply two storms to the boxes. The first storm consisted of a constant intensity of 62.5 mm/hr for 1 hour. The second storm contained varying intensities of 62.5, 90.1, and 25 mm/hr in 20 minute intervals. Runoff samples were obtained to measure sediment concentration, orthophosphates, nitrates and ammonia, as well as total phosphorus and nitrogen content. Soil samples at varying depths were also collected for nutrient analysis to quantify the movement of phosphorus and nitrogen down through the soil. Preliminary results indicate that the PAM treatment significantly increased time to runoff, decreased total runoff volume, and decreased total sediment yield for each storm individually, as well as for combined storms. PAM treatments were also found to be effective in reducing the loss of soluble ammonium and orthophosphate in surface runoff from the wastewater treated soil. No significant difference, however, was detected in the loss of nitrites and nitrates between PAM and control treatments. These results indicate that application of PAM with wastewater during surface irrigation may be a viable method for protecting water bodies from excessive nutrient and sediment loads during rainfall events occurring subsequent to land application of wastewater.