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Submitted to: Review Article
Publication Type: Review Article Publication Acceptance Date: 7/26/2004 Publication Date: 12/1/2004 Citation: Woodbury, B.L., Miller, D.N. 2004. Simple protocol for determining dust potentials from cattle feedlot soils. ASAE Resource Magazine, December: p 11-12. Interpretive Summary: Dust from cattle feedlots is not only an annoyance but can be an important avenue for odor emissions, pathogen dispersion, and nutrient loss. Increased public intolerance of these emissions has prompted feedlot operators to search for management strategies to control dust. Unfortunately, many important factors controlling dust production are poorly understood. To help understand these mechanisms a simple, inexpensive laboratory technique was developed for investigating the potential to generate dust. Though the measured potentials are not suitable for predicting actual dust emission, results provide a means to evaluate various dust control management strategies. Technical Abstract: Cattle feedlot dust is an annoyance and may be a route for nutrient transport, odor emission, and pathogen dispersion, but important environmental factors that contribute to dust emissions are poorly characterized. A general protocol was devised to test feedlot samples for their ability to produce dust under a variety of environmental conditions. A blender was modified to produce dust from a variety of dried feedlot surface and soil samples and collect airborne particles on glass fiber filters by vacuum collection. A general blending protocol optimized for sample volume (150 to 175 cubic centimeters), blending time (5 min pre-blending), and dust collection time (15 s) provided consistent dust measurements for all samples tested. The procedure performed well on samples that varied in organic matter content, but was restricted to samples containing less than 1.8 to 7.1 g water/kg DM. When applied to field samples, the technique demonstrated considerable spatial variability between feedlot pen sites. Mechanistically, dust potential was related to moisture and organic matter content. An alternative protocol also demonstrated differences within pen sites in maximum dust potential and dust airborne residence time. The two protocols were not intended, nor are they suitable, for predicting actual particulate matter (PM) emissions from agricultural sources. Rather, the protocols rapidly and inexpensively compared the potential for dust emission from samples of differing composition under a variety of environmental conditions. |
