Using NMR-based metabolomics to monitor the biochemical composition of agricultural soils: A pilot study

NMR-based metabolomics plays a major role in the study of complex living systems. While there is a known connection between soil microbial metabolism and productivity in agricultural systems, very few researchers describe the application of NMR to the evaluation of agricultural soil metabolomes. Here, we introduce a simple protocol for the NMR metabolic analysis of biochemical compounds from agricultural soils where microbial communities are influenced by the application of anaerobic soil disinfestation (ASD). Following ASD treatment, aqueous metabolites were extracted from soil samples and the compound identities of the resulting mixtures were determined using 1D and 2D NMR in combination with metabolome database searches. It was found that the ASD treatments altered the metabolite composition of soil as evidenced by the detection of natural biochemical products such as organic acids. Principle component analysis revealed distinct biochemical differences between non-treated and ASD-treated soils. Our findings support that this protocol is efficacious in the rapid and reliable determination of metabolite profiles even within complex mixtures obtained from ASD-treated agricultural soils. Thus, NMR spectroscopy has the potential to impact soil science by investigating the adaptable biochemical fingerprint of soil metabolomes in agricultural fields, knowledge of which may be used to improve crop production.