Soil Organic Nitrogen Components and N−Cycling Enzyme Activities Following Vegetation Restoration of Cropland in Danxia Degraded Region

Vegetation restoration significantly improves soil organic nitrogen (SON) components and enhances N-cycling enzyme activities in the ecologically fragile Danxia degraded region (DDR), offering a promising strategy for soil quality recovery. The study found that restoring cropland to grassland, shrubland, or arbor forest increased amino sugar N and amino acid N while reducing non-hydrolyzable N, with grassland restoration proving most effective for boosting SON levels and N-fixation capacity. Restoration also elevated key enzyme activities such as nitrate reductase, denitrifying enzymes, protease, and β-1,4-N-acetylglucosaminidase, alongside microbial biomass, indicating an enhanced intrinsic soil nitrogen cycle. These changes were linked to the mineralization and fixation of organic matter via amorphous iron and proteases, ultimately improving available soil nitrogen. The findings provide a scientific foundation for optimizing vegetation restoration practices in degraded regions like China Danxia.

Wang, C., Yang, Q., Zhang, C., Zhou, B., Li, X., Zhang, X., Chen, J., & Liu, K. (2022). Soil Organic Nitrogen Components and N−Cycling Enzyme Activities Following Vegetation Restoration of Cropland in Danxia Degraded Region. Forests, 13(11), 1917. https://doi.org/10.3390/f13111917