%0 Journal Article %A Shimotsuma, Moe %A Uchida, Yoshitaka %A Nakajima, Yasuhiro %A Akiyama, Hiroko %D 2017 %T The effects of rice (Oryza sativa L. ssp. japonica) husk biochar on nitrogen dynamics during the decomposition of hairy vetch in two soils under high-soil moisture condition %U https://tandf.figshare.com/articles/journal_contribution/The_effects_of_rice_i_Oryza_sativa_i_L_ssp_japonica_husk_biochar_on_nitrogen_dynamics_during_the_decomposition_of_hairy_vetch_in_two_soils_under_high-soil_moisture_condition/4754233 %R 10.6084/m9.figshare.4754233.v1 %2 https://ndownloader.figshare.com/files/7797250 %K N2O %K N2 %K andosol %K fluvisol %K soil type %X

Legumes, including hairy vetch (Vicia villosa Roth), are widely used as green manures. They fix nitrogen (N) and provide the N to other crops when they decompose, and thus are considered alternatives for chemical N fertilizers. However, N-rich plant residues, including hairy vetch, are also sources of soil nitrous oxide (N2O) emissions, a greenhouse gas. On one hand, rice (Oryza sativa L. ssp. japonica) husk biochar is widely used as a soil conditioner in Japan and has been reported as a tool to mitigate soil N2O emissions. We conducted a soil core incubation experiment (1.5 months) to compare the N2O emissions during the decomposition of surface-applied hairy vetch (0.8 kg dried hairy vetch m−2 soil) under semi-saturated soil moisture conditions (~100% water-filled pore space (WFPS)), using two soil types, namely Andosol and Fluvisol. Throughout the incubation period, the use of biochar suppressed soil NH4+-N concentrations in Andosol, whereas the effect of biochar on NH4+-N was not clear in Fluvisol. Biochar increased the nitrate (NO3-N) levels both in Andosol and Fluvisol, suggesting a negative influence on denitrification and/or a positive influence on nitrification. Biochar application did not influence the cumulative N2O emissions. Our study suggests that rice husk biochar is not a good option to mitigate N2O emissions during the decomposition of surface-applied hairy vetch, although this study was performed under laboratory conditions without plants. However, the trends of the inorganic-N concentration changes followed by the addition of hairy vetch and biochar were markedly different between the two soil types. Thus, factors behind the differences need to be further studied.

%I Taylor & Francis