Welcome to Chinese Journal of Ecology! Today is Share:

cje

Previous Articles     Next Articles

Effects of biochar addition on the availability of heavy metals and soil quality in red paddy soil.

WEN Xin, CHEN Xiao-min*, GUO Bi-lin, JING Feng, HU Shi-min, LI Lian-qing   

  1. (College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China).
  • Published:2020-04-10

Abstract: A field experiment was conducted to examine the impacts of biochar addition on soil physicochemical properties, concentrations of heavy metals, and soil quality of a red paddy soil in Hunan Province, China. Biochar was added at dosage of 0, 10, 20, 30, and 40 t·hm-2 before the rice was transplanted in 2017. Soil samples in tilled layer (0-17 cm) and plow solelayer (17-29 cm) were collected in September 2018. Soil quality was evaluated by soil quality index (SQI). The results showed that biochar addition reduced soil bulk density but increased soil porosity, soil pH, the concentrations of organic matter and dissolved organic carbon (DOC). The contents of ammonium and available phosphorus were the highest at the treatments of 10 and 30 t·hm-2. Biochar addition enhanced the activities of soil urease, catalase and sucrose. The concentrations of cadmium (Cd), arsenic (As) and lead (Pb) in the red paddy soil werereduced by biochar addition, especially at the 40 t·hm-2 treatment. The concentrations of heavy metals and their influence factors were analyzed by stepwise regression. In the tilled layer, the contents of available Cd, As and Pb were significantly correlated with urease activity, soil pH, and sucrose activity, respectively. However, the contents of available Cd, As and Pb were significantly correlated with urease, catalase activities and available phosphorus content in the plow sole layer, respectively. The values of SQI among treatments decreased in the order: A40>A30>A20>A10>CK, with corresponding value of 0.641, 0.638, 0.579, 0.533, and 0.464, respectively. This result indicates that the quality of red paddy soil was the highest at the application amount of biochar is 40 t·hm-2. In conclusion, biochar addition can effectively reduce the availability of heavy metals and improve soil quality.