Soil as a Medium for Dairy Liquid Waste Disposal

Abstract

Abstract A vegetative‐soil filter may be an inexpensive and effective means for the disposal of liquid dairy wastes. A field study was conducted at Southern Illinois University Dairy Center, Carbondale, Ill. during 1976–77 to evaluate the effectiveness of a vegetative‐soil filter for disposal of dairy effluent. The liquid waste was applied daily to tall fescue ( Festuca arundinacea Schreb.) on a Hosmer silt loam (Typic Fragiudalf) with a 3% north‐facing slope. Applying effluent to the soil for absorption without runoff was found to eliminate the possibility of stream pollution except during rainfall and snowmelt runoff. The highest loading rate for this soil under the most adverse climatic conditions was 0.43 cm/day. The pollutants in the liquid waste were reduced significantly by flowing over the vegetative‐soil filter but not to acceptable levels. The BOD 5 , NH 4 ‐N, suspended solids, and PO 4 ‐P decreased by 41, 36, 69, and 16%, respectively. After 1 year of liquid waste application to the test site, perched ground‐water samples showed a 99% BOD 5 decrease and a 90% removal of PO 4 ‐P. A vegetative‐soil filter may be used for the disposal of liquid waste effluent from a dairy operation.