Fine Particulate Emissions after Applying Biosolids to Agricultural Land.

The management of biosolids is important to ensure the safety and well-being of urban and rural communities. A recent national survey estimated 60% of biosolids produced in the USA are applied to land. Biosolids applied to land must meet EPA standards for metal and pathogen content, but there remains a perceived threat of exposure to metals and pathogens after application. Biosolids may stimulate biological activity and enhance soil aggregation and water retention, thus there is a likelihood that biosolids applied to soil could reduce the threat of wind erosion. Wind erosion threatens air quality and the sustained use of the soil resource in the western US, thus there is interest in applying biosolids to land to reduce wind erosion and enhance soil productivity. This study examined the effect of biosolid applications on emission of fine particulates from agricultural land in the Inland Pacific Northwest United States. Synthetic fertilizer and biosolids were applied to a silt loam in the spring during the fallow phase of a winter wheat – summer fallow rotation. Fertilizer and biosolids were applied as main plot treatments and conventional and conservation tillage were imposed as subplot treatments. Fine particulate emissions were assessed after the first rodweeding and sowing winter wheat using a portable wind tunnel. Emission of particulates was measured using an isokinetic sampler and Dusttrak aerosol monitors inside the tunnel at a wind velocity of 16 m s^-1 for 17 minutes. Particulate emissions were greater for conventional than conservation tillage, but no differences were observed between fertilizer and biosolids treatments. Our preliminary results suggest that biosolids may not affect fine particulate emissions from agricultural soils.