Innovative Technologies Can Improve Understanding of Microbial Nitrogen Dynamics in Agricultural Soils

Core Ideas: Innovative technologies improve metadata quality for soil N cycle omics studies. Microfluidics and automated sensing enhance tracking of N cycle intermediates and products. Model microfabricated systems offer greater control of microbial habitat conditions. Multiple approaches can achieve parallel quantification of N cycling genes. Insights from small-scale studies can inform field-scale management to reduce N losses. Roughly half of all nitrogen (N) added to soils is not incorporated by crops and is lost to the environment, but our ability to reduce N loss from soils is hampered by an inadequate grasp of microbial processes affecting N retention and mobility. High-throughput sequencing (HTS) of microbial DNA is enabling fundamental insights into N cycling microorganisms and their metabolisms. This commentary describes six emerging technologies that could be combined with HTS to enable real-time collection of metadata on N transformations, intermediates, and products to link soil properties, microbial processes, and the fate of N. These technologies include microdialysis and microfluidics, automated sensing, microfabrication of model soils, parallel quantification of N functional genes, sorting active cells, and stable isotope probing. Use of integrated technologies applied initially under controlled conditions at small scales can lead to identification of soil conditions and field-scale management practices that promote better N conservation and delivery to agricultural crops.