Nitrogen turnover and N2O/N2 ratio of three contrasting tropical soils amended with biochar
Biochar has been reported to reduce emission of nitrous oxide (N2O) from soils, but the mechanisms responsible remain fragmentary. For example, it is unclear how biochar effects on N2O emissions are mediated through biochar effects on soil gross N turnover rates. Hence, we conducted an incubation st...
| Autores principales: | , , , , , , , , , , , |
|---|---|
| Formato: | Journal Article |
| Lenguaje: | Inglés |
| Publicado: |
Elsevier
2019
|
| Materias: | |
| Acceso en línea: | https://hdl.handle.net/10568/106108 |
| _version_ | 1855527119763800064 |
|---|---|
| author | Fungo, B. Chen, Z. Butterbach-Bahl, Klaus Lehmannn, J. Saiz, Gustavo Braojos, V. Kolar, A. Rittl, T.F. Tenywa, M.M. Kalbitz, K. Neufeldt, H. Dannenmann, Michael |
| author_browse | Braojos, V. Butterbach-Bahl, Klaus Chen, Z. Dannenmann, Michael Fungo, B. Kalbitz, K. Kolar, A. Lehmannn, J. Neufeldt, H. Rittl, T.F. Saiz, Gustavo Tenywa, M.M. |
| author_facet | Fungo, B. Chen, Z. Butterbach-Bahl, Klaus Lehmannn, J. Saiz, Gustavo Braojos, V. Kolar, A. Rittl, T.F. Tenywa, M.M. Kalbitz, K. Neufeldt, H. Dannenmann, Michael |
| author_sort | Fungo, B. |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Biochar has been reported to reduce emission of nitrous oxide (N2O) from soils, but the mechanisms responsible remain fragmentary. For example, it is unclear how biochar effects on N2O emissions are mediated through biochar effects on soil gross N turnover rates. Hence, we conducted an incubation study with three contrasting agricultural soils from Kenya (an Acrisol cultivated for 10-years (Acrisol10); an Acrisol cultivated for over 100-years (Acrisol100); a Ferralsol cultivated for over 100 years (Ferralsol)). The soils were amended with biochar at either 2% or 4% w/w. The 15N pool dilution technique was used to quantify gross N mineralization and nitrification and microbial consumption of extractable N over a 20-day incubation period at 25 °C and 70% water holding capacity of the soil, accompanied by N2O emissions measurements. Direct measurements of N2 emissions were conducted using the helium gas flow soil core method. N2O emissions varied across soils with higher emissions in Acrisols than in Ferralsols. Addition of 2% biochar reduced N2O emissions in all soils by 53 to 78% with no significant further reduction induced by addition at 4%. Biochar effects on soil nitrate concentrations were highly variable across soils, ranging from a reduction, no effect and an increase. Biochar addition stimulated gross N mineralization in Acrisol-10 and Acrisol-100 soils at both addition rates with no effect observed for the Ferralsol. In contrast, gross nitrification was stimulated in only one soil but only at a 4% application rate. Also, biochar effects on increased NH4+ immobilization and NO3-consumption strongly varied across the three investigated soils. The variable and bidirectional biochar effects on gross N turnover in conjunction with the unambiguous and consistent reduction of N2O emissions suggested that the inhibiting effect of biochar on soil N2O emission seemed to be decoupled from gross microbial N turnover processes. With biochar application, N2 emissions were about an order of magnitude higher for Acrisol-10 soils compared to Acrisol-100 and Ferralsol-100 soils. Our N2O and N2 flux data thus support an explanation of direct promotion of gross N2O reduction by biochar rather than effects on soil extractable N dynamics. Effects of biochar on soil extractable N and gross N turnover, however, might be highly variable across different soils as found here for three typical agricultural soils of Kenya. |
| format | Journal Article |
| id | CGSpace106108 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 2019 |
| publishDateRange | 2019 |
| publishDateSort | 2019 |
| publisher | Elsevier |
| publisherStr | Elsevier |
| record_format | dspace |
| spelling | CGSpace1061082024-10-03T07:40:54Z Nitrogen turnover and N2O/N2 ratio of three contrasting tropical soils amended with biochar Fungo, B. Chen, Z. Butterbach-Bahl, Klaus Lehmannn, J. Saiz, Gustavo Braojos, V. Kolar, A. Rittl, T.F. Tenywa, M.M. Kalbitz, K. Neufeldt, H. Dannenmann, Michael soil environment nitrification ammonification Biochar has been reported to reduce emission of nitrous oxide (N2O) from soils, but the mechanisms responsible remain fragmentary. For example, it is unclear how biochar effects on N2O emissions are mediated through biochar effects on soil gross N turnover rates. Hence, we conducted an incubation study with three contrasting agricultural soils from Kenya (an Acrisol cultivated for 10-years (Acrisol10); an Acrisol cultivated for over 100-years (Acrisol100); a Ferralsol cultivated for over 100 years (Ferralsol)). The soils were amended with biochar at either 2% or 4% w/w. The 15N pool dilution technique was used to quantify gross N mineralization and nitrification and microbial consumption of extractable N over a 20-day incubation period at 25 °C and 70% water holding capacity of the soil, accompanied by N2O emissions measurements. Direct measurements of N2 emissions were conducted using the helium gas flow soil core method. N2O emissions varied across soils with higher emissions in Acrisols than in Ferralsols. Addition of 2% biochar reduced N2O emissions in all soils by 53 to 78% with no significant further reduction induced by addition at 4%. Biochar effects on soil nitrate concentrations were highly variable across soils, ranging from a reduction, no effect and an increase. Biochar addition stimulated gross N mineralization in Acrisol-10 and Acrisol-100 soils at both addition rates with no effect observed for the Ferralsol. In contrast, gross nitrification was stimulated in only one soil but only at a 4% application rate. Also, biochar effects on increased NH4+ immobilization and NO3-consumption strongly varied across the three investigated soils. The variable and bidirectional biochar effects on gross N turnover in conjunction with the unambiguous and consistent reduction of N2O emissions suggested that the inhibiting effect of biochar on soil N2O emission seemed to be decoupled from gross microbial N turnover processes. With biochar application, N2 emissions were about an order of magnitude higher for Acrisol-10 soils compared to Acrisol-100 and Ferralsol-100 soils. Our N2O and N2 flux data thus support an explanation of direct promotion of gross N2O reduction by biochar rather than effects on soil extractable N dynamics. Effects of biochar on soil extractable N and gross N turnover, however, might be highly variable across different soils as found here for three typical agricultural soils of Kenya. 2019-08 2019-12-11T12:28:45Z 2019-12-11T12:28:45Z Journal Article https://hdl.handle.net/10568/106108 en Open Access Elsevier Fungo, B., Chen, Z., Butterbach-Bahl, K., Lehmannn, J., Saiz, G., Braojos, V., Kolar, A., Rittl, T.F., Tenywa, M., Kalbitz, K., Neufeldt, H. and Dannenmann, M. 2019. Nitrogen turnover and N2O/N2 ratio of three contrasting tropical soils amended with biochar. Geoderma 348:12-20. |
| spellingShingle | soil environment nitrification ammonification Fungo, B. Chen, Z. Butterbach-Bahl, Klaus Lehmannn, J. Saiz, Gustavo Braojos, V. Kolar, A. Rittl, T.F. Tenywa, M.M. Kalbitz, K. Neufeldt, H. Dannenmann, Michael Nitrogen turnover and N2O/N2 ratio of three contrasting tropical soils amended with biochar |
| title | Nitrogen turnover and N2O/N2 ratio of three contrasting tropical soils amended with biochar |
| title_full | Nitrogen turnover and N2O/N2 ratio of three contrasting tropical soils amended with biochar |
| title_fullStr | Nitrogen turnover and N2O/N2 ratio of three contrasting tropical soils amended with biochar |
| title_full_unstemmed | Nitrogen turnover and N2O/N2 ratio of three contrasting tropical soils amended with biochar |
| title_short | Nitrogen turnover and N2O/N2 ratio of three contrasting tropical soils amended with biochar |
| title_sort | nitrogen turnover and n2o n2 ratio of three contrasting tropical soils amended with biochar |
| topic | soil environment nitrification ammonification |
| url | https://hdl.handle.net/10568/106108 |
| work_keys_str_mv | AT fungob nitrogenturnoverandn2on2ratioofthreecontrastingtropicalsoilsamendedwithbiochar AT chenz nitrogenturnoverandn2on2ratioofthreecontrastingtropicalsoilsamendedwithbiochar AT butterbachbahlklaus nitrogenturnoverandn2on2ratioofthreecontrastingtropicalsoilsamendedwithbiochar AT lehmannnj nitrogenturnoverandn2on2ratioofthreecontrastingtropicalsoilsamendedwithbiochar AT saizgustavo nitrogenturnoverandn2on2ratioofthreecontrastingtropicalsoilsamendedwithbiochar AT braojosv nitrogenturnoverandn2on2ratioofthreecontrastingtropicalsoilsamendedwithbiochar AT kolara nitrogenturnoverandn2on2ratioofthreecontrastingtropicalsoilsamendedwithbiochar AT rittltf nitrogenturnoverandn2on2ratioofthreecontrastingtropicalsoilsamendedwithbiochar AT tenywamm nitrogenturnoverandn2on2ratioofthreecontrastingtropicalsoilsamendedwithbiochar AT kalbitzk nitrogenturnoverandn2on2ratioofthreecontrastingtropicalsoilsamendedwithbiochar AT neufeldth nitrogenturnoverandn2on2ratioofthreecontrastingtropicalsoilsamendedwithbiochar AT dannenmannmichael nitrogenturnoverandn2on2ratioofthreecontrastingtropicalsoilsamendedwithbiochar |