deepfrontier Postdoc and PhD projects Leanne Peixoto

Leanne Peixoto

Leanne Peixoto of Canada did her Ph.D. at Department of Agroecology in the Section of Climate and Water at University of Aarhus.

PhD thesis: Mitigating climate change: the potential for long-term soil carbon storage in subsoil from deep rooted crops.

Her research was targeted towards the potential for long-term soil carbon storage from deep rooted crops by quantifying the effect of deep rooted crops on soil carbon stock. Leanne used the root towers at Højbakkegård to:

  • Isotopic techniques such as 14C/13C dual labelling
  • Compound-specific stable isotope probing
  • Amino sugars
  • Phospholipid fatty acids

The primary goal of her study was to assess the potential of deep-rooted crops for climate change mitigation. This was achieved by the quantification of root-derived carbon input in deep soil layers from deep rooted crops.

Additionally, in order to understand the factors that control deposition and decomposition, she evaluated the potential mechanisms of soil carbon stabilization of root-derived carbon from deep rooted crops and the influence of deep rooted crops on microbial activity and rhizosphere processes within deep soil layers.

Leanne also worked in the field facility, the DeepRootLab, as she is involved in the DeepRootLab collaborative project ‘Nitrogen effects on carbon deposition and sequestration in deep soil from deep-rooted crops’.

Leanne commenced her study on September 1st 2017 and is expected to finish on September 1st 2021.

The three soil cores to 1.5 meter depth within the DeepRootLab.
Soil cores to 1.5 meter depth were taken inside all labeling plots, and cores were subdivided into four depth intervals: 0-25, 25-50, 50-100 and 100-150 cm.
Using the lift to isotopically label the plants grown on the top of the RootTowers.
Leaf 13C labeling to determine the net rhizodeposition among the deep-rooted crops. Eppendorf tubes containing 1 mL of the labeling solution of NaOH (10-5 M) with 13C labeled bicarbonate (99 atom%, 0.01 M).
Removing soil samples and associated roots within the RootTowers.
13CO2-labeling in a chamber setup with 1 m2 subplots established with fixed frames in the ground for both kernza and lucerne.
13CO2-labeling in a chamber setup with 1 m2 subplots established with fixed frames in the ground for both kernza and lucerne.
13CO2-labeling in a chamber setup with 1 m2 subplots established with fixed frames in the ground for both kernza and lucerne.
13CO2-labeling in a chamber setup with 1 m2 subplots established with fixed frames in the ground for both kernza and lucerne.
Soil cores to 1.5 meter depth were taken inside all labeling plots, and cores were subdivided into four depth intervals: 0-25, 25-50, 50-100 and 100-150 cm.

> See publications from Deep Frontier

Leanne Peixoto's Paper in Soil Biology and Biochemistry selected as editor's choice

Editor's comments: "I liked this paper because they examined soil carbon dynamics in soil depth well beyond what most other studies would consider as the rooting zone of crops. Essentially, they reveal that these deep soils have potential for long-term carbon storage, but importantly, when they are planted with deep-rooted crops”

Read the paper here  

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Revised 24.10.2024
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Helene Uller-Kristensen