Date of Award
Master of Science
Biosystems Engineering Technology
C. Roland Mote
Dan Yoder, Ron Yoder
A field experiment combming erosion control and waste disposal was conducted at the Plateau Experiment Station near Crossville, Tennessee. Beef cattle manure was surface applied to nine conventionally-tilled plots. The study was performed to determine the erosion-prevention potential of livestock waste when surface applied on disturbed soil. Also studied was the quality of runoff from these plots over a span of four weeks The plots were on a Typic Hapludult soil with a slope of 7-10%. An impermeable metal border surrounded the 11.18 m by 4.06 m plots. The border contained all water that fell in the plots, while preventing any water that fell outside the plots from entering. Manure was hand applied one day after tillage was completed. Surface coverage percentages of 0 (control plot), 30, and 80% were replicated three times. Manure spread on the 30% and 80% plots averaged 6.35 and 14.21 t/ha (dry matter), respectively. Three runoff events were produced by a solid set rain simulator. The rain simulator consisted of 41 irrigation sprinklers mounted on risers 3 m high. Due to limitations of the system, three plots (one bank) were irrigated at a time. Each of the three banks contained a 0%, 30%, and 80%-cover plot. Average intensity of the rainfall delivered by the simulator was 3.6 cm/h. The average coefficient of uniformity for simulated rainfall distribution on all plots was 0.76. Rain 1 was applied immediately after manure application. Rains 2 and 3 were applied 1 week and 4 weeks after manure application, respectively. Runoff freely flowed to the lower end of the plots where a collection apparatus was in place. Runoff fell over a metal lip inserted flush with the soil surface. The water then drained via gravity into a multislot divisor box. A portion (1/9) of the runoff exiting the divisor box was collected and weighed. Samples of the runoff were collected before it entered the divisor box and were transported to the lab for analysis. Runoff samples were analyzed for total solids, total volatile solids, total Kjeldahl nitrogen, and total phosphorus. Total runoff was found by using the weight of water collected from the divisor box. Analysis showed that, when normalized by the volume of rainfall applied, the mass of total solids and the volume of runoff exiting the plots decreased significantly with increases in applied percent cover. Based on the concentration of total solids in runoff leaving the plots erosion was reduced by the presence of cover, but the two levels of cover were not different in their impact on erosion. Elapsed time-since-application of manure had no effect on the mass of total solids in the runoff. The mass of volatile solids leaving the plots in the runoff was significantly less for the control plots (0% residue cover) than for the plots with manure cover. However, when normalized by volume of rainfall applied, significantly less volatile solids left the plots containing manure. Time had no effect on the mass of volatile solids leaving the plots. The concentration of total Kjeldahl nitrogen in the runoff from the control plots was significantly larger than that from the plots containing manure. Although, no difference existed in total Kjeldahl nitrogen leaving the plots when normalized by the amount of rainfall applied. Time had no effect on the mass of nitrogen leaving the plots. Off-site movement of phosphorus was not appreciably impacted by any of the observed treatments.
Easterly, Craig Allen, "Evaluation of Manure as Cover on Tilled Soils. " Master's Thesis, University of Tennessee, 1996.