Nitrogen release and carbon mineralisation from soil organic matter fractions in three cotton crop rotation and natural vegetation soils

Data consists of results from a 14-day incubation experiment measuring nitrogen (N) mobilisation and carbon (C) mineralisation from coarse (≥ 50 μm) and fine (≤ 50 μm) soil organic matter (SOM) fractions, whole soil, and whole soil treated with dispersal and lyophilization as per separated fractions. The aims of this experiment were to determine the contribution of SOM fractions of N mineralisation, to validate measurement of separated SOM fractions against whole soil, and to determine if theorised mechanisms of C stabilisation predict N stability in SOM fractions.
Nitrogen mobilisation was measured as the change in concentration of dissolved organic N (DON), free amino acid-N (FAAN), nitrate (NO3) and ammonium (NH4) concentrations, and carbon mineralisation measured as cumulative carbon dioxide (CO2) evolution. Soils (0-10 cm) from four management systems were included: continuous cotton (CC), cotton-vetch rotation (CV), cotton-wheat rotation (CW) and nearby uncleared vegetation (NV; mixed native and invasive species). The soil is classified as a Grey Vertosol under the Australian Soil Classification (Isbell 2016). The data also includes fraction or soil organic C and total N content measured by Leco combustion, and C content in particulate-, humic- and resistant organic C (POC, HOC and ROC, respectively) fractions measured by Leco and 13C-NMR as per Baldock et al. 2013, Soil Res. ROC is split into ROC-total (ROC_t), ROC-coarse (ROC_c), and ROC-fine (ROC_f).
Full details of methods and presentation of data can be found in “Opposing patterns of carbon and nitrogen stability in soil organic matter fractions”, European Journal of Soil Science, in press.
Associated R code for data processing and statistical analysis can be found here: https://zenodo.org/doi/10.5281/zenodo.11063487