A promising and simple method to quantify soil/manure mixing on beef feedlot pens

Abstract

Abstract. On beef cattle feed pen surfaces, fresh and decayed manure is mixed with base rock or soil (base). Quantifying this mixing has beneficial applications for aspects including nutrient and greenhouse gas budgeting. However, no practical methods exist to quantify mixing. We investigated if measuring element concentrations in: (A) fresh manure, (B) base material, and (C) pen manure offers a promising method to quantify manure/base mixing on pen surfaces. Using three operational beef feedlots as study sites, we targeted carbon (C), and silicon (Si), which are the two most abundant and easily measurable organic and inorganic elements. Our results revealed that C concentrations were strongly (>15 times) and significantly (P < 0.05) higher whereas Si concentrations strongly (>10 times) and significantly (P < 0.01) lower in fresh manure than base material at all three sites. These relative concentrations were not significantly impacted by manure decay, as determined by an 18-week incubation experiment. This suggested that both of these elements are suitable markers for quantifying base/manure mixing on pens. However, due to the chemical change of manure during decay, C was shown to be an imprecise marker of base/manure mixing. By contrast, using Si to estimate base/manure mixing was largely unaffected by manure decay. These findings were confirmed by measuring C and Si concentrations in stockpiled pen surface manure from one of the sites. Using Si concentrations is a promising approach to quantify base/manure mixing on feed pens given that this element is abundantly concentrated in soils and rocks.

Temporal Nitrous Oxide Emissions from Beef Cattle Feedlot Manure after a Simulated Rainfall Event

“…Apparent water losses due to evaporation over the 45‐d period from the entire pan, as determined by weekly weighing of the pans, were 4.8, 6.9, 9.2, 11.6, and 22.5 kg for TRT 1, 2, 3, 4, and 5, respectively. These calculated water losses do not account for mass loss due to biological decay or ammonia volatilization and as such may be inflated (Pratt et al, 2015).…”

<b>Enteric and feces methane emissions, fermentative ruminal parameters and feeding behavior of cattle fed cottonseed and vitamin E</b>

“…Volumetric methane yield of 0,13-0,16 L CH 4 /g VS-fed were found in Pratt's et al (2016) study. Other studies have (IPCC, 2006) reported 0,17 L CH 4 /g VS-fed and variation of 0,07-0,28 L CH 4 /g VS-fed (Gopalan et al 2013).…”