Assessment of the net mitigation effect of vegetative environmental buffer (VEB) to reduce ammonia and particulate matter (PM) emissions

Abstract

Concentrated animal feeding operations (CAFOs), such as poultry farms, contribute significantly to air pollution, particularly ammonia (NH₃) and particulate matter (PM) emissions. Vegetative environmental buffers (VEBs) offer a sustainable, cost-effective, and low-maintenance solution for mitigating NH₃ and PM emissions from CAFOs, and some previous studies showed that pollutant concentrations behind the VEBs were substantially reduced compared with concentration directly from the source. However, due to the lack of a controlled dataset for non-VEB situations, the net effect of VEBs could hardly be assessed. Thus, the dataset from the previous study was used to develop a methodology for quantitatively evaluating the efficacy of VEBs in reducing NH₃ and PM emissions from a poultry house, and to distinguish the net pollutant reduction achieved by VEBs from those resulting merely from atmospheric dilution and dispersion. The results showed that VEB can effectively mitigate air pollutants emissions and attributes enhanced ground-level reductions of NH₃ (72.7 % ± 9.1 %), total suspended particle (TSP) (61.9 % ± 10.0 %), PM₁₀ (62.5 % ± 9.9 %) and PM_2.5 (94.6 % ± 6.5 %). In addition, VEB demonstrated better mitigation performance during daytime. Meteorological conditions showed no correlation with pollutant concentrations or enhanced reduction ratios while significant positive correlations between reductions of NH₃ and PM were also observed. These results demonstrated that VEBs are effective in reducing NH₃ and PM emissions from poultry houses. The results from this study will inform conservation practice guidelines and assist land managers in employing VEBs for poultry house emitted air pollution reductions.