Effects of Biochar Amendment on the Dynamics of Enzyme Activities from a Paddy Soil Polluted by Heavy Metals

Abstract

Reducing heavy metals mobility and improve the soil physical-chemical property in order to reduce plant uptake would be an urgent demand for safe rice production in China. A field experiment was conducted for the research of biochar (BC) amendment on the dynamics of soil enzyme activities in a contaminated paddy soil after 2 years. BC was applied in 2009 before rice transplantation at rates of 0, 10, 20, 40 t ha-1, and three undisturbed soil cores of 0 to 15 cm depth were sampled from each plot for physicochemical analysis and enzymatic monitoring. Compared to the control, the soil pH and SOC were significantly increased by 2–5 % and 16–51 % after BC amendment. The activities of cellulase, urine enzyme, neutral phosphatase and sucrase were also found to increase by 117.4–178.3 %, 31.1–37.6 %, 29.7–193.8 % and 36.5–328.6 %, respectively. Furthermore, there were positive correlation of soil enzyme activities with soil pH and SOC content. Data in this research indicated that BC amendment may be potential in improvement of soil properties to some extent to achieve the agricultural use. Introduction