What should we think of when we hear the term “agroforestry?” Lettuce at the bottom and an apple tree at the top, or something like that?
Lettuce and apple trees definitely, but the trees are usually in rows. You have a great many approaches to choose from in agroforestry. For example, you can combine poplars or fruit trees with farmland or have cows, sheep or pigs grazing under your trees. Alternatively, you can add in strips of fast-growing woody plants if you want to generate energy.
What are the benefits of agroforestry?
Many, from protecting against erosion and improving biodiversity and the water balance through to helping us adapt to climate change and protect the climate as it is now.
Has it already been done anywhere in Germany?
Yes, in loads of places, and more are being added all the time. There’s a map as well: https://defaf.map.agroforestry-map.eu/de#5.31/51.333/10.437
How does agroforestry help bind CO2 from the atmosphere?
CO2 accumulates in the aboveground biomass, in roots and in the soil, which is disturbed a lot less under trees than it is out in the fields. Landscapes with extensive agroforestry clearly contain much, much more CO2 than if they were just farmland.
How much CO2 per hectare can this kind of agroforestry bind?
I’d say up to 15 metric tons per hectare per year, potentially. But that depends very much on what system you’re using and how well everything grows. By way of comparison, the carbon footprint of the average person in Germany is around 10 metric tons a year.
What exactly are you looking at in your project entitled “Agroforestry’s Biophysical potentials for CDR and Decision making across scales,” or “ABCDR” for short?
It’s about studying agroforestry’s potential for binding CO2 from the atmosphere. At the Potsdam Institute for Climate Impact Research (Potsdam-Institut für Klimafolgenforschung, PIK), this is being estimated on a large scale using two existing models, LPJmL and MAgPIE.
Who’s leading the overall project?
The PIK. We’re in charge of our subproject but are working closely with our colleagues at the PIK and holding regular meetings. ABCDR is another individual project within the CDRterra program.
What’s your role in this project?
Our subproject is looking at things on an individual farm scale. Our team, driven mainly by Dr. Marcos Jimenez-Martinez, used our “decision analysis” approach to model the impact of agroforestry on a farm, focusing particularly on obstacles to implementation. We organized stakeholder workshops and company visits to develop several conceptual models for the results of the agroforestry, which we then translated into mathematical models for simulation purposes.
How might the results help to remove CO2 from the atmosphere?
The results could help policymakers undertake a realistic assessment of the great potential that agroforestry holds and then use this as a basis for devising suitable support measures.
How close are you to practical implementation?
We’re already using our results in our conversations with policymakers, local chambers of agriculture and the like, who are the intended “next users” of our policy-based studies.
So what comes next?
There’s likely to be a follow-up project, where we want to apply our methodology to other forms of land use. We’re also sharing our findings with decision-makers via our networks.
Information on CDRterra: https://cdrterra.de/en/results-phase-1/
Information on Professor Lüdeling’s research: https://www.gartenbauwissenschaften.uni-bonn.de/en
