Long-term fertilization promotes the microbial-mediated transformation of soil dissolved organic matter

Summary

Understanding dissolved organic matter (DOM) transformation is crucial for comprehending soil biogeochemical cycling. However, the extent that soil microbes mediate DOM transformation at the molecular level, and whether this is regulated by fertilization remain largely unknown. Here we investigated soil DOM transformations under long-term fertilization using Fourier-transform ion cyclotron resonance mass spectrometry, high-throughput sequencing, and machine learning. Fertilization greatly promoted transformation potential of DOM molecules. Organic fertilization increased the mean transformation number of DOM molecules by 260% compared to no-fertilization, while chemical fertilization increased it by 193%. Machine learning indicated that intrinsic DOM molecular characteristics could predict