Improving the Sustainability of Dairy Slurry by A Commercial Additive Treatment

Abstract

Ammonia (NH3), methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) emissions from livestock farms contribute to negative environmental impacts such as acidification and climate change. A significant part of these emissions is produced from the decomposition of slurry in livestock facilities, during storage and treatment phases. This research aimed at evaluating the effectiveness of the additive “SOP LAGOON” (made of agricultural gypsum processed with proprietary technology) on (i) NH3 and Greenhouse Gas (GHG) emissions, (ii) slurry properties and N loss. Moreover, the Life Cycle Assessment (LCA) method was applied to assess the potential environmental impact associated with stored slurry treated with the additive. Six barrels were filled with 65 L of cattle slurry, of which three were used as a control while the additive was used in the other three. The results indicated that the use of the additive led to a reduction of total nitrogen, nitrates, and GHG emissions. LCA confirmed the higher environmental sustainability of the scenario with the additive for some environmental impact categories among which climate change. In conclusion, the additive has beneficial effects on both emissions and the environment, and the nitrogen present in the treated slurry could partially displace a mineral fertilizer, which can be considered an environmental credit.

Effects of SOP Lagoon Additive on Gaseous Emissions from Stored Liquid Dairy Manure

“…In the present experiments, the manure was collected from the lagoon which likely assured the presence of methanogens that needed a few days to be established. This is in contrast to what was reported by Borgonovo et al, who showed peak emissions at day 4 [24]. These observed differences between the experiments may be due to the substrate to which the treatment was applied.…”

“…This may limit the complete understanding of the mechanism of SOP Lagoon on emission reduction. The shorter duration of application is consistent with Borgonovo et al but this time frame may be too short to fully understand the long term effects of emissions on a commercial dairy lagoon after application of SOP LAGOON [24].…”

“…Many of the results were obtained using a considerable amount of material (3% to 10% of manure wet weight) making the application not practical in real-world conditions. Borgonovo et al first published results on this specific commercial additive (SOP LAGOON), made of gypsum processed with proprietary technology, and found that the addition of the products to fresh liquid manure has a reduction potential of 21.5% of CH 4 , 22.9% of CO 2 , 100% of N 2 O and 100% of NH 3 emissions on day 4, even at very low dosages [24]. It should be mentioned that similar to other commercial additives, the exact manufacturing process of SOP Lagoon is unknown due to confidentiality [13].…”

“…Li [20,21,23]. A recent study by Borgonovo et al tested the gypsum-based commercial additive, "SOP LAGOON", on fresh dairy manure and found the additive to be effective in reducing direct NH 3 and GHG emissions [24]. With the use of a Life Cycle Analysis (LCA) they also found a positive mitigation to climate change and particulate matter formation.…”

Effect of SOP “STAR COW” on Enteric Gaseous Emissions and Dairy Cattle Performance

“…However, a synergistic effect of the components in SOP has never been researched for CH 4 mitigation. Borgonovo et al (2019) and Peterson et al (2020) [31,32] found that gypsum processed with SOP's proprietary technology reduced NH 3 and GHG emissions in liquid manure with a much lower dosage of gypsum than reported previously [33]. However, this same effect with low doses was not seen in the current study.…”