Abstract
It is essential to reveal the variations in the activities of carbon (C)-cycling enzymes in soil aggregates of different sizes, so as to shed more light on the soil organic C (Corg) dynamics in the tea plantation ecosystems. In this study, the activities of cellobiohydrolase, xylanase, β-glucosidase, and invertase were detected in soil aggregates obtained at the depth of 0–20 cm from tea plantations of various ages (8, 17, 25, and 43-yr.) in hilly region of southern Guangxi, China. Soil aggregates were divided into >2, 2–1, 1–0.25, and <0.25 mm fractions through a dry sieving procedure. This study hypothesized that the potential of soil Corg decomposition would be higher at early stage (in the initial 17-yr.) than that at late stage (after 17-yr.). Our results suggested that, irrespective of the tea planting age, soil aggregate-related Corg contents were mainly distributed in the >2 and 2–1 mm fractions, and soil aggregates at the >2 mm sizes had the highest activities of C-cycling enzymes. Notably, the C-cycling enzyme activities in soil aggregates were closely correlated with Corg availability, and Corg contents might not exert a vital part. On the other hand, tea planting for a long time could promote soil Corg to be accumulated. At early stage, the accumulated soil Corg was primarily derived from the >2 mm fractions; meanwhile, the C-cycling enzyme activities in the >2 mm fractions were also markedly elevated, indicating that the accumulated Corg in soils at early stage was more easily decomposed and showed a higher potential of decomposition than that at late stage, thus supporting our hypothesis. Overall, the youthful tea plantations in the initial 17-yr. showed an increasing trend with respect to the potential of soil Corg decomposition; however, when tea plantations became mature, the potential of soil Corg decomposition was reduced in hilly region of southern Guangxi, China.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.