Row crop agriculture is a significant source of two major greenhouse gases (GHGs) (carbon dioxide [CO2] and nitrous oxide [N2O]) and the air pollutant precursor ammonia (NH3). Fluxes of these naturally occurring trace gases are often augmented by agricultural practices, such as fertilizer application and crop systems management. A living mulch system (LMS) maintains a live cover crop year‐round and is an emerging agricultural system that can reduce pesticide and fertilizer use while maintaining yields. Multiple trace gas fluxes of GHGs and NH3 had not previously been measured together in an LMS of corn (Zea mays L.) and white clover (Trifolium repens L.). This study compared soil gas fluxes in a white clover LMS with two other cover crop systems and a no‐cover‐crop system. Infrared and gas chromatography measurements were taken over 2 yr in northern Georgia. Mean soil CO2 and N2O fluxes (159.7 kg ha−1 d−1 and 0.027 kg N ha−1 d−1, respectively) observed in LMS plots exceeded those from other treatments. Soil temperature, moisture, potentially mineralizable nitrogen (N), and nitrate partially explained these differences. Mean soil NH3 emissions were greater in LMS (0.089 kg N ha−1 d−1) compared with no cover crop (0.038 kg N ha−1 d−1). Increased N2O and NH3 fluxes could be from release of N from decomposition of clover and from release of N into the soil as the corn shades the clover. Although LMS plots did not reduce trace gas emissions, labile carbon content was at least 100 mg kg−1 greater than other treatments after 2 yr, improving soil health.

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Urban agriculture and gardening provide many health benefits, but the soil is sometimes at risk of heavy metal and metalloid (HMM) contamination. HMM, such as lead and arsenic, can result in adverse health effects for humans. Gardeners may face exposure to these contaminants because of their regular contact with soil and consumption of produce grown in urban areas. However, there is a lack of research regarding whether differential exposure to HMM may be attributed to differential knowledge of exposure sources. In 2018, industrial slag and hazardous levels of soil contamination were detected in West Atlanta. We conducted community-engaged research through surveys and follow-up interviews to understand awareness of slag, HMM in soil, and potential remediation options. Home gardeners were more likely to recognize HMM health effects and to cite health as a significant benefit of gardening than community gardeners. In terms of knowledge, participants were concerned about the potential health effects of contaminants in soil yet unconcerned with produce in their gardens. Gardeners’ knowledge on sources of HMM exposure and methods for remediation were low and varied based on racial group.

Health effects resulting from exposures to heavy metals and metalloids (HMM) are a globally recognized problem (Martin & Griswold, 2009;Tchounwou et al., 2012), yet these hazards still persist in many urban areas in the United States (US). The common HMM that pose threats to human health are lead (Pb), cadmium (Cd), chromium (Cr), and arsenic (As) (Järup, 2003), with Pb being one of the most harmful to human health and children's neurological development. Over the last 35 years, the Centers for Disease Control and Prevention (CDC) has been continuously lowering the reference value for blood Pb levels (BLLs) in children aged 0-6 years from 10 μg/dL to 5 μg/dL in 2012 and to the current 3.5 μg/dL set in 2021 (Centers for Disease Control, 2022). Still, approximately 86,000 children below 6 years of age were identified with BLLs above 5 μg/dL across the US in 2018 (Centers for Disease Control, 2022). In 2018, 2,333 children below 6 years of age in Georgia were identified with BLLs above 5 μg/dL. This number was derived from a screening rate of about 20%, thus it is likely that the true number is much greater than what is reported (Distler & Saikawa, 2020). Permanent neurologic damage and behavior disorders have been associated with low BLLs, prompting the CDC to state that there is no safe BLL for