Livestock Manure Windrow Composting Runoff And Infiltration Characteristics from Laboratory Rainfall Simulations

Abstract

Windrow-composted livestock manure has been shown to be less hazardous to the environment compared to manure directly applied to cropland and other agricultural areas. Although offsite contaminant losses through runoff and leaching can occur during the composting process, these losses are suspected to increase under different compost moisture conditions and as composted materials mature. This research quantified the effects of windrow-composted livestock manure and straw bedding components on runoff and infiltration characteristics from laboratory rainfall simulations. Compost samples collected on three dates at approximately the beginning (day 0), middle (day 30), and end (day 60) of a June-July 2004 field research windrow composting period were used for this rainfall simulation study. Replicated compost windrow-shaped cross-section samples were constructed in a specially-designed Plexiglas container apparatus for viewing and recording infiltrated leachate wetting front position boundary movement from simulated rainfall events. Runoff and leachate samples were collected and analyzed for drainage volumes and concentrations and total mass losses of sediment, nitrate-nitrogen (NO 3 -N), and ortho-phosphorus (PO 4 -P) during and following rainfall simulation trials. Leachate wetting front position boundary movement was significantly lower for day 60 compost samples compared among day 0 and day 30 compost sample material. Drainage volume analysis results indicated significantly higher average runoff versus leachate volumes within all compost sampling dates, and runoff volumes were significantly higher among day 30 and day 60 compost samples compared to runoff volumes from day 0 compost samples. Average sediment, NO 3 -N, and PO 4 -P concentrations were significantly higher in leachate versus runoff within all compost sampling dates. Conversely, the total mass losses of these contaminants were significantly higher in runoff compared to leachate within all compost sampling dates. Results of this study suggest that biological and mechanical functions of the composting process reduced compost sample aggregates and increased compost bulk density. We hypothesize that these changes in compost material structure and porosity volume decreased infiltration and increased runoff sediment, NO 3 -N, and PO 4 -P losses during the second and final compost sampling stages of a field windrow composting period. DisciplinesAgricultural Science | Agriculture | Agronomy and Crop Sciences | Bioresource and Agricultural Engineering Comments

Nitrogen and Phosphorus in Runoff from Cattle Manure Compost Windrows of Different Maturities

“…However, when extended to 24 h from the onset of rain simulation, VRC increased to 0.53 to 0.84, which corresponded to our values during mid‐ to late active composting. Webber et al (2011) reported a VRC of 0.25 on Day 0 for manure/straw in a compost windrow cross‐section container apparatus, which was very similar to our initial value of 0.24 for a similar feedstock. Their VRC increased to 0.39 for Day 30 compost, which, although lower than our estimate of 0.49 for Day 30, supported the trend of increased VRC with increased maturity.…”

“…In fact, the highest runoff rates and VRCs occurred with lower AWC (Days 81 and 109). Webber et al (2011) found no significant difference in VRC between unsaturated and saturated composts. During the humification of organic matter as compost matures, carbohydrates (hydrophilic‐C) decrease, whereas alkyl‐ and aromatic‐C (hydrophobic‐C) compounds increase (Aguiar et al, 2013; Spaccini and Piccolo, 2009).…”

“…Simulated rain has advantages over natural rainfall because it can be scheduled at specific times and at equal intensities during composting to assess maturity effects on runoff characteristics. In a laboratory rain simulation, Webber et al (2011) suggested that biological and mechanical processes reduced compost aggregate size and increased bulk density, which led to increases in runoff volumes and sediments during the final stages of composting a manure/straw bedding mix. Qureshi et al (2003) showed that microbial activity (as controlled by incubation temperatures) affected the release and concentrations of trace elements in biosolids leachate.…”

Pile Structure in Large Animal Carcass Compost Piles: Zone Differences in Physical and Chemical Characteristics

“…Studies have documented nutrient losses, either through leaching or runoff, from a wide range of compost feedstock mixtures, including: animal manures (Eghball et al 1997;Glanville et al 2006;King et al 2009King et al , 2014Martins and Dewes 1992;Seymour and Bourdon 2003;Ulen 1993;Webber et al 2011), food waste (Krogmann and Woyczechowski 2000), and yard waste (Ballestero and Douglas 1996). There is not a universal agreement on the relative importance of these mechanisms, however.…”

Release and Removal of Microorganisms from Land-Deposited Animal Waste and Animal Manures: A Review of Data and Models

“…Treatments used to reduce microbial concentrations in manure, such as composting and digesting, could affect microbial release as well. Webber et al (2011) performed a windrow composting study and conducted rainfall simulations over composted manure (mixture of straw bedding, dairy cow waste, horse waste, and sheep waste) on Days 0, 30, and 60 of composting and measured NO 3 -N, PO 4 -P, and sediment losses in runoff and leachate. The authors reported significantly lower leachate volumes and higher runoff volumes of all contaminants as the composting time increased, which was attributed to changes in manure bulk density, aggregation, porosity, and water contents (i.e., physical contents related to manure consistency).…”