Impact of Eucalyptus biochar application to upland rice-sugarcane cropping systems on enzyme activities and nitrous oxide emissions of soil at sugarcane harvest under incubation experiment

Abstract

This research studied the effect of biochar addition before upland rice planting, followed by sugarcane cropping, on soil fertility (nitrogen mineralization, β-glucosidase and urease activities), and mitigating greenhouse gases emission at sugarcane harvest. An incubation experiment was designed utilizing soil samples taken from a sugarcane field at final harvest with treatments, (i) Control, with no biochar or fertilizer application to upland rice (ii) CF, with fertilizer application at recommended rates; (iii) BC1, with biochar addition at the rate of 3.125 Mg ha⁻¹ + CF; (iv) BC2, with biochar addition at the rate of 6.25 Mg ha⁻¹ + CF. Results showed that, at the last sampling dates, soil enzyme activities of the biochar treatments were significantly greater than those of the control treatment. The lowest cumulative carbon dioxide and nitrous oxide emission was observed in the BC2 treatment. Thus, the BC2 treatment could increase both soil fertility and mitigate global warming.

Keywords:

• mineral N
• microbial biomass N
• β-glucosidase
• urease
• carbon dioxide

Additional information

Funding

The authors would like to thank TRG 5780303 under the Thailand Research Fund for financial support.