Effects of Earthworms and Organic Materials on Soil Structure in Tea Plantation

Clc Number:

Fund Project:

the National Natural Science Foundation of China (31800590), the Special Fund for the Construction of Modern Agricultural Industry Technology System (CARS-19), and the Funding Project of Jiangsu University

  • Article
  • |
  • Figures
  • |
  • Metrics
  • |
  • Reference
  • |
  • Related
  • |
  • Cited by
  • |
  • Materials
  • |
  • Comments

    [Objective] Earthworms in the soil may help improve soil structure and fertility significantly through activities, like feeding, excreting, mucus secreting, excavating, etc. To explore the effects of earthworms as affected by application of organic materials of different kinds on the soil of a tea plantation, a pot experiment, designed to have five treatments, i.e. (i) no fertilizer input (CK), (ii) earthworms only (BE), (iii) rapeseed cake plus earthworms (CE), (iv) tea tree pruning plus earthworms (JE), and (v) biochar plus earthworms (TE), was conducted with tea trees planted in each of the pots (30 cm in diameter and 35 cm in height).[Method] Three months after the start of the experiment, soil samples were collected from each of the pots for analysis, after being air dried. Soil pH was measured using a pH meter; concentrations of soil organic carbon (SOC) and total nitrogen (TN) were quantified with a CN analyzer (Vario EL, Elementar GmbH); mineral-organic complex in soil microaggregates were characterized with the synchrotron radiation infrared micro-imaging method; intact particles (100-500 mm), varying in shape, were screened out with a 2-mm-sieve, frozen at -20℃, and then prepared with a cryomicrotome (Cyrotome E, Thermo Shandon Limited, UK) into thin sections (2 μm in thickness), which were eventually transferred into infrared-reflecting MirrIR Low-E microscope Slides (Kevley Technologies, Ohio, USA). Then distribution of SOCs of various forms and clay minerals (OH) was determined with the aid of Synchrotron radiation-based Fourier-transform infrared spectromicroscopy.[Result] Results show that Treatment BE was higher than CK in content of soil total carbon in, but lower than in Treatment CE, JE and TE in content of total carbon, total nitrogen and organic matter; and Treatment TE group was the highest. Earthworm inoculation alone (Treatment CE) increased total carbon and organic matter content in the soil, and addition of organic materials (Treatment JE and TE) enhanced the effect, and addition of tea biochar (Treatment TE) had the best effect. All the treatments showed a decreasing trend in soil pH, and the trend was especially significant in Treatment BE (from 6.81 to 5.82). Furthermore, the synchrotron radiation microzone infrared spectra demonstrated that polysaccharides, proteins, fats and clay minerals in soil aggregates were highly heterogeneous. Clay minerals and macromolecular organics in Treatment CE and JE were highly dispersed. Minerals and polysaccharides were quite similar while clay minerals, protein and fat were quite different in distribution, and their distributions were had nothing to do with any interactions between earthworms and organic materials. Correlation analysis between clay minerals and organic functional groups shows that the correlation coefficients of clay minerals and organic functional groups in the five fractions of soil aggregates followed an increasing trends:clay minerals-protein < clay minerals-polysaccharide < clay minerals-fat, which indicates that clay minerals varied in affinity with macromolecular organics and their relationships were not affected by any interactions between earthworms and organic materials.[Conclusion] In summary, soil organic amendments initialize a positive feedback loop by increasing SOC, which promotes interactions between minerals and organic components in the soil, and thereby may possibly serve as a soil management tool for enhancing carbon storage in the soil.

    Cited by
Get Citation

CHENG Siyuan, LI Huan, MEI Huiling, WANG Xuanqing, LIU Xinqiu, CHEN Xuan, MA Qingping, LI Xinghui. Effects of Earthworms and Organic Materials on Soil Structure in Tea Plantation[J]. Acta Pedologica Sinica,2021,58(1):259-268.

Article Metrics
  • Abstract:
  • PDF:
  • HTML:
  • Cited by:
  • Received:November 04,2019
  • Revised:March 14,2020
  • Adopted:April 09,2020
  • Online: October 30,2020
  • Published: January 11,2021