Root-mycorrhizal interactions unlock mineral nutrients and stimulate organic carbon emmision under straw addition

The objectives of this study were to (1) assess the synergistic effect between roots and associated microorganisms on CO2 and N2O efflux and C mobilization; (2) examine the effects of root-microorganism interactions on the libarationg of Ca, Ma and the formation of reactive Fe mineral; and (3) identify the key bacterial and fungal communities responsible to environmental variables and greenhouse gas emissions. To accomplish these, a series of well-controlled microcosm experiments were conducted to elucidate the synergistic role of roots and associated microorganisms, in governing the liberation of dissolved organic C and mineral elements in the rhizosphere from three soils, including sand soil, clay soil, and sand plus clay soil. The 16S rRNA gene-based Illumina MiSeq high-throughput sequencing was used to characterize the bacterial and fungal community. In addition, correlative scanning electron microscopy (SEM) and nanoscale secondary ion mass spectrometry (NanoSIMS) were integrated to identify the localization of carbon and other bioactive elements (Fe and Si) as well as the effects of root exudate chemistry on the mobility of mineral-protected organic carbon in soils.