Attributes of C and N natural abundances and the stoichiometry of extractable nutrients as influenced by different land use types: Application of stable isotopes

Understanding the transformation of soil nutrients and characteristics of ecological stoichiometry in soils is vigorous in sustainable land management and ecosystem health. This study characterized the soil carbon(C), nitrogen (N) natural abundances and stoichiometric relationships of C, N, P (phosphorus), extractable nutrients including potassium (K), zinc (Zn), manganese (Mn), nickel (Ni), copper (Cu), and chromium (Cr) across various land use types and soil depths of Jeldu District, West Showa zone, Oromia, Ethiopia. The soil samples collected from different land use types and soil depths in 2025 were analyzed for soil pH, cation exchange capacity (CEC), available P, total P, extractable nutrients, C, N concentrations, natural abundances of δ 1 3 C, and δ 1 5 N isotopes using their corresponding standard laboratory procedures and instruments. It had been shown that there are decreasing trends in soil pH; CEC, total phosphorus, and extractable K were revealed from soils of (forest → grazing → cultivated) lands. The concentrations of C and N in the litter layer have shown significant variations with increasing soil depths. Similarly, the total C, N concentrations, and ratios of C:N and N:P have also shown significant variation across different soil depths of forest land and at 0‐ to 20‐cm depths of other land use types, whereas the values of δ 1 3 C and δ 1 5 N isotopes did not show significant variation. The findings indicate that the litter layer of forest land holds higher levels of soil C and N concentrations, total N, C:N, and N:P, and some extractable nutrients than other land use types and deeper soils. Our study details that variations in land use types and soil depths were found to be the main indicators that control the contents, stoichiometric features, dynamics, and natural abundances of soil nutrients. Furthermore, this study enhances an understanding of soil C and N natural abundance and stoichiometric ratios of C:N and N:P across land use types and soil depths, and it provides comprehensions for sustainable management of soil nutrients, natural resources, and health of the ecosystem.