|SCHUSTER, NICOLE - University Of Nebraska|
|BARTELT-HUNT, SHANNON - University Of Nebraska|
|LI, XU - University Of Nebraska|
|MARX, DAVID - University Of Nebraska|
|SCHMIDT, AMY - University Of Nebraska|
|SNOW, DANIEL - University Of Nebraska|
Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2016
Publication Date: 2/1/2017
Publication URL: http://handle.nal.usda.gov/10113/5763079
Citation: Schuster, N.R., Bartelt-Hunt, S., Durso, L.M., Gilley, J.E., Li, X., Marx, D.B., Schmidt, A.M., Snow, D.D. 2017. Runoff nutrient and microbial transport following swine slurry application. Transactions of the ASABE. 60(1)/53-66. doi: 10.13031/trans.11370.
Interpretive Summary: This study was conducted to measure the effects of swine slurry application method and time following slurry application on runoff transport of nutrients and microbials. Swine slurry from a commercial wean-to-finish swine production facility was applied to field plots using broadcast or injection methods at a rate required to meet annual nitrogen requirements for corn. Three simulated rainfall events were applied to the experimental plots for 30-minute duration, separated by 24 h intervals. Following the third rainfall simulation event, inflow was applied at the top of each plot in four successive increments to simulate greater plot lengths. The dissolved phosphorous (DP) and total phosphorus (TP) loads measured on the broadcast treatment were significantly greater than the values obtained from the injected treatment. As time following slurry application increased from 2 to 44 days, DP, TP, and microbial transport rates significantly decreased. Overland flow rate was a critical variable significantly affecting each of the measured water quality parameters with nutrient runoff loads significantly increasing as runoff rate increased. Slurry application method, time following slurry application, and runoff rate are important variables affecting nutrient and microbial transport from land application areas.
Technical Abstract: This study was conducted to measure the effects of swine slurry application method, time following slurry appli-cation, and runoff rate on selected water quality characteristics. Slurry from a commercial swine operation was broadcast or injected on field plots at a rate required to meet annual nitrogen requirements for corn. Rainfall simulation tests were conducted at five varying periods following slurry application. During each study period, three simulated rainfall events, separated by 24 h intervals, were applied for 30 min duration at an intensity of approximately 70 mm h-1. Following the third rainfall simu-lation event, inflow was applied at the top of the plots in four successive increments to simulate greater plot lengths. Runoff samples were collected for analyses of dissolved P (DP), particulate P, total P (TP), NO3-N, NH4-N, total N, electrical con-ductivity, pH, and soil loss. The DP and TP loads of 0.35 and 0.46 kg ha-1 measured for the broadcast treatment were signifi-cantly greater than the 0.13 and 0.19 kg ha-1 obtained for the injection treatment. As time following slurry application increased from 1 to 3 days to 43 to 45 days, DP, TP, and NH4-N loads decreased from 0.35 to 0.14, from 0.52 to 0.18, and from 2.17 to 0.14 kg ha-1, respectively. Runoff rate significantly affected each of the measured water quality parameters. Runoff loads of DP, TP, and NH4-N increased from 10.1 to 29.8, from 12.9 to 35.5, and from 13.9 to 25.1 g ha-1 min-1, respectively, as overland flow rate increased from 2.3 to 12.6 L min-1. Application method, time following slurry application, and runoff rate are im-portant variables influencing water quality characteristics of runoff.