Journal article

Publication year: 2018

Pages: 171-180

Journal: Soil Biology and Biochemistry

Volume number: 120

ISSN: 0038-0717

eISSN: 1879-3428

DOI Link: https://doi.org/10.1016/j.soilbio.2018.02.008

Publisher: Elsevier

Abstract: 
Understanding soil nitrogen (N) dynamic and availability during afforestation (the conversion of cropland to forest plantations) is critical to maintain forest growth and long-term productivity, especially in rainfall-rich, subtropical region. However, only few studies have investigated the inherent N transformation processes involved in N availability in subtropical acidic soils. In a N-15 tracing study, nine soils from croplands, 10-y and 50-y afforested woodlands were sampled to investigate the changes in soil gross N transformation rates in humid subtropical China. Gross N transformation rates were not significantly different in soils under 10- and 50-y after afforestation. Compared to cropland, however, afforestation stimulated the rates of mineralization, microbial NH4+ immobilization and adsorption of NH4+, leading to a faster turnover of NH4+ pool in afforested soils. Moreover, afforestation inhibited autotrophic nitrification and resulted in NO3- production dominated by heterotrophic nitrification. Furthermore, afforestation significantly enhanced NO3- consumption mainly through the increase in microbial NO3- immobilization rather than dissimilatory NO3- reduction to NH4+ in soil. These differences in gross N transformation rates resulted in low net NO3- production and strong NO3- retention capacity in afforested soils, similar to that found in undisturbed natural forest. Our results suggest a rapid recovery (several years) of soil N retention following afforestation. Soil NO3- retention capacity was correlated positively with TOC, TN, WHC, CEC, Al, free Al oxide and exchangeable Al3+, but negatively with pH, Ca and exchangeable Ca2+, indicating that the absence of agricultural management (e.g., N fertilizer and liming) and alteration in soil environment by tree establishment are responsible for the recovery of N retention capacity in subtropical acidic soils during afforestation.

Harvard Citation style: Xie, Y., Yang, L., Zhu, T., Yang, H., Zhang, J., Yang, J., et al. (2018) Rapid recovery of nitrogen retention capacity in a subtropical acidic soil following afforestation, Soil Biology and Biochemistry, 120, pp. 171-180. https://doi.org/10.1016/j.soilbio.2018.02.008

APA Citation style: Xie, Y., Yang, L., Zhu, T., Yang, H., Zhang, J., Yang, J., Cao, J., Bai, B., Jiang, Z., Liang, Y., Lan, F., Meng, L., & Müller, C. (2018). Rapid recovery of nitrogen retention capacity in a subtropical acidic soil following afforestation. Soil Biology and Biochemistry. 120, 171-180. https://doi.org/10.1016/j.soilbio.2018.02.008