Effects of magnesite on nitrogen conversion and bacterial community during pig manure composting

The objective of this research was to elucidate the effect of varying proportions of magnesite (MS) addition – 0% (T1), 2.5% (T2), 5% (T3), 7.5% (T4), and 10% (T5) - on nitrogen transformation and bacterial community dynamics during pig manure composting. In comparison to T1 (control), MS treatments amplified the abundance of Firmicutes, Actinobacteriota, and Halanaerobiaeota, bolstered the metabolic functionality of associated microorganisms, and enhanced the nitrogenous substance metabolic pathway. A complementary effect in core bacillus species played a key role in nitrogen preservation. Compared to T1, 10% MS demonstrated the most substantial influence on composting because Total Kjeldahl Nitrogen increased by 58.31% and NH3 emission decreased by 41.52%. In conclusion, 10% MS appears to be optimal for pig manure composting, as it can augment microbial abundance and mitigate nitrogen loss. This study offers a more ecologically sound and economically viable method for curtailing nitrogen loss during composting.