Smart residue amendments to improve greenhouse gas uptake by agricultural soils
Microbial Ecology and Applied Microbiology
Ecology of Land Use
Final Report Abstract
Atmospheric concentrations of greenhouse gases (GHG) increased since the industrial revolution dramatically. Approximately 25% originates from agricultural practices and land-use changes. Some organic fertilizers generally applied to increase soil fertility in a sustainable way, have been shown to turn agricultural soils into sinks of GHG. This opens up the possibility to minimize GHG emissions by optimizing fertilizer application by modulating composition and concentration. To achieve and evaluate this possibility, I first incubated an agricultural soil with different organic amendments (compost, sewage sludge, digestate, cover crop residue mixture) in a climate chamber incubation set-up, either as a single application or in a mixture under different soil moisture concentrations and different amounts. GHG fluxes were measured continuously, while changes in abundance of GHG relevant microbial groups (nitrifiers, denitrifiers, methanotrophs) were measured at the beginning and the end of the incubation. While the GHG emissions were strongly dependent on soil moisture and the amount of organic fertilizers, several combinations of amendments led to a promising reduction of GHG emissions compared to un-amended soil. Thereby compost combination with other organic amendments as well as cover crop residues showed the best overall performance on reducing the GHG balance and increasing microbial groups that are involved in pathways in GHG reduction or reducing microbial groups that are producing GHGs. In a second step, I tested the best performing organic amendments from the first experiment in a more natural setting with the introduction of a plant and against a mineral fertilizer as control, again under controllable conditions in a climate chamber. A second soil type was used to evaluate the influence of different physico and chemical parameters. Also, in this set-up, the organic amendments stimulated the GHG reduction and positively manipulated the abundance and composition of microbial groups involved in GHG transformation (nitrifiers, methanogens, methanotrophs, and denitrifiers). Additionally, the application of organic amendment showed the same or an improving plant yield production compared to the usage of standard mineral fertilizers. The next logical approach would be to conduct an experiment under field conditions to observe if these processes are also applicable under changing environmental conditions. However, these obtained results already indicating the clear potential to use organic amendments as a smarter way of fertilization strategy.
Publications
- (2017). Smart residue amendments to improve greenhouse gas uptake by agricultural soils. K(C)lever CCping Workshop, Kleve, Germany
Brenzinger, K., Drost, S., Liu, X., Korthals, G., and Bodelier, P.
- (2018). Organic residue amendments to modulate greenhouse gas emissions from agricultural soils. Frontiers in microbiology, 9, 3035
Brenzinger, K., Drost, S. M., Korthals, G., & Bodelier, P. L.
(See online at https://doi.org/10.3389/fmicb.2018.03035) - (2018). Smart residue amendments to modulate greenhouse emissions from agricultural soils. 23rdEuropean Nitrogen Cycle Meeting, Alicante, Spain
Brenzinger, K., Drost, S., Korthals, G., and Bodelier, P.
- (2019). Modulating greenhouse gas balance by combinations of organic amendments. Netherlands Annual Ecology Meeting | NERN, Lunteren, The Netherlands
Brenzinger, K., Drost, S., Korthals, G., and Bodelier, P.
