Gross N transformations and N2O fluxes in biochar-amended soils
Final Report Abstract
Our results show by 15N labelling-tracing that different biochars in different soil environments can capture considerable amounts of nitrate (rather than ammonium), and that this is partly delivered to the growing plants. We showed that already N-enriched biochar was more efficient in taking up newly added 15N than untreated biochar (rather than being “already full”). We also show that nitrate capture by biochar may be a mechanism contributing to reduced N2O emissions with biochar. Particularly the co-composted N-enriched biochar behaved as an (anion) exchange soil constituent. Such a pyrogenic C associated mechanism may contribute to the fertility of PyC-rich soils (ADE soils, chernozems). Our results indicate that research efforts may help to design biochars in such a way that they balance biochar-N protection against N-leaching or N2O-emission losses and release to plants on demand. This may deliver the muchwanted increase in the N-use efficiency of agricultural production in the well-known way that fertile, resilient soils do (Terra preta, study 1). We envisage that further research efforts may enable to use biochar as a fertilizer carrier material (as done with great success by Schmidt et al., 2015). Biochar may be used as N-retaining soil and compost amendment or surplus-N management tool in agriculture (e.g. animal husbandry) to reduce environmental pollution burden by excess N. However, more R&D is clearly needed to unravel mechanisms to deliberately design biochars.
Publications
- (2017) Biochar as a tool to reduce the agricultural greenhouse-gas burden–knowns, unknowns and future research needs. Journal of Environmental Engineering and Landscape Management, 25 (2) 114-139
Kammann, C., Ippolito, J., Hagemann, N., Borchard, N., Cayuela, M. L., Estavillo, J. M., Fuertes-Mendizabal, T., Jeffery, S., Kern, J., Novak, J., Rasse, D., Saarnio, S., Schmidt, H.-P., Spokas, K., & Wrage-Mönnig, N.
(See online at https://doi.org/10.3846/16486897.2017.1319375) - (2014) Biochar, hydrochar and uncarbonized feedstock application to permanent grassland—Effects on greenhouse gas emissions and plant growth. Agriculture, Ecosystems & Environment, 191, 39-52
Schimmelpfennig S, Müller C, Grünhage L, Koch C, Kammann C
(See online at https://doi.org/10.1016/j.agee.2014.03.027) - (2015) Biochar but not humic acid product amendment affected maize yields via improving plant-soil moisture relations. Plant and Soil, 395, 141-157
Haider G, Koyro H-W, Azam F, Steffens D, Müller C, Kammann C
(See online at https://doi.org/10.1007/s11104-014-2294-3) - (2015) Changes in macro- and micronutrient contents of grasses and forbs following Miscanthus x giganteus feedstock, hydrochar and biochar application to temperate grassland. Grass and Forage Science, 70
Schimmelpfennig S, Kammann C, Moser G, Grünhage L, Müller C
(See online at https://doi.org/10.1111/gfs.12158) - (2015) Microbial community shifts 2.6 years after top dressing of Miscanthus biochar, hydrochar and feedstock on a temperate grassland site. Plant and Soil, 397, 261-271
Rex D, Schimmelpfennig S, Jansen-Willems A, Moser G, Kammann C, Müller C
(See online at https://doi.org/10.1007/s11104-015-2618-y) - (2015) Plant growth improvement mediated by nitrate capture in co-composted biochar. Scientific Reports, 5
Kammann CI, Schmidt H-P, Messerschmidt N et al.
(See online at https://doi.org/10.1038/srep11080) - (2016) Standard extraction methods may underestimate nitrate stocks captured by field aged biochar. Journal of Environmental Quality, 45, 1196-1204
Haider G, Steffens D, Müller C, Kammann CI
(See online at https://doi.org/10.2134/jeq2015.10.0529) - (2017) Biochar reduced nitrate leaching and improved soil moisture content without yield improvements in a four-year field study. Agriculture, Ecosystems & Environment, 237, 80-94
Haider G, Steffens D, Moser G, Müller C, Kammann CI
(See online at https://doi.org/10.1016/j.agee.2016.12.019)
