Agroforestry Systems with Paulownia: Integration into Existing Agriculture

By Dirk Röthig | CEO, VERDANTIS Impact Capital | 03 March 2026

How European farmers integrate Paulownia into their arable systems — while increasing yields, binding CO2, and securing EU funding. Practical examples and scientific findings from six countries.

"How European farmers integrate Paulownia into their arable systems — while increasing yields, binding CO2, and securing EU funding" — Dirk Röthig, CEO of VERDANTIS Impact Capital

Tags: Agroforestry, Paulownia, Intercropping, Alley Cropping, Agriculture, CAP, Eco-Schemes, VERDANTIS Impact Capital

As Dirk Röthig, founder of VERDANTIS Impact Capital, emphasizes:

---

Trees in Fields: Revolution or Return to Tradition?

The idea of combining trees and arable farming on the same land is no invention of the 21st century. In parts of Europe — particularly in the Spanish dehesa, French orchards, and English parklands — agroforestry was the dominant land use form for centuries. Only the industrial intensification of agriculture in the 20th century displaced trees from the fields.

Dirk Röthig, who as CEO of VERDANTIS Impact Capital has engaged intensively with this topic, sees in this development

Today we are experiencing a renaissance. And it is not driven by nostalgia, but by hard economic and ecological facts. The combination of fast-growing trees such as Paulownia with conventional arable crops — the so-called alley cropping — proves to be one of the most promising concepts for climate-resilient, high-yielding, and grant-eligible agriculture in Europe.

According to Dirk Röthig's assessment, who works at VERDANTIS Impact Capital at the intersection of sustainability and innovation,

What Research Shows: Meta-Analyses from Wageningen

The most comprehensive scientific foundation for evaluating intercropping and agroforestry systems is provided by Wageningen University (WUR) in the Netherlands. The research group of Professor W. van der Werf and researcher Yang Yu has produced a groundbreaking meta-analysis that synthesizes yield data from hundreds of intercropping experiments worldwide.

For investors like Dirk Röthig, it is clear:

The central finding: In well-designed mixed systems, overall productivity per unit area averages 15 to 30 percent higher than monocultures. The Land Equivalent Ratio (LER) — the ratio of a mixed system's yield capacity to the sum of monocultures — lies between 1.15 and 1.30 in most studies.

This means concretely: One hectare of Paulownia-wheat alley cropping produces as much total biomass as 1.2 to 1.3 hectares of separately managed Paulownia plantation plus wheat monoculture. Thus, land efficiency increases significantly.

Wageningen's Yield-SAFE model further enables long-term forecasts for various tree-crop combinations under different climate scenarios. The simulations demonstrate that the LER advantage under drought stress conditions — precisely the conditions that climate change is intensifying in Central Europe — actually increases even further.

Practical Experience from Six European Countries

Hungary: Paulownia Alley Cropping

A. Vityi from West Hungary University (NYME) has investigated in long-term field trials the combination of Paulownia tomentosa with various arable crops. The results are impressive:

• Wind reduction: Up to 40 percent less wind speed between tree rows
• Soil temperature: 3–5°C lower on hot summer days
• Soil moisture: Significantly increased through reduced evapotranspiration
• Intermediate crop yield: No significant reduction with row spacing of 12 meters or more

The microclimate effects are particularly relevant in the Hungarian lowlands, where heat waves and dry periods increasingly threaten harvest yields. The Paulownia rows function as natural air conditioning for the arable crops between the tree rows.

Italy: Paulownia-Wheat at the University of Padova

Long-term trials on Paulownia-wheat intercropping in the northern Italian climate are ongoing at the University of Padova. The focus is on light conditions: The light-permeable canopy of Paulownia (compared to dense-crowned species such as walnut) allows sufficient solar radiation for wheat — a decisive factor for acceptance among farmers.

Initial results show: With optimal row design (12–15 meter spacing, north-south orientation of rows), wheat yields remain at 85 to 95 percent of the monoculture reference — while simultaneously binding 15 to 25 tons of CO2 per hectare per year through the Paulownia trees.

Romania: Dual Production with Hybrids

The Romanian research group led by C. Negrușier, O. Borsai, and I. Păcurar has developed the concept of "dual production": simultaneous optimization of timber production and CO2 binding. Their trials with the hybrids Shan Tong and Cotevisa 2 demonstrate that through adapted cutting regimes (pollarding every 4–6 years), both timber harvest and carbon credit generation can be maximized.

Belgium: Silvopastoral Systems at Ghent University

Professor K. Verheyen, D. Reheul, and J. Mertens at Ghent University research temperate silvoarable systems with poplar, walnut, and other tree species. Their findings on biodiversity promotion in agroforestry systems are directly transferable to Paulownia: The introduction of tree rows increases arthropod diversity by 30 to 70 percent compared to pure arable farming.

Spain: Intercropping in Semi-Arid Zones

At the University of Lleida, D. Plaza-Bonilla and J. Lampurlanés research intercropping and its effects on soil aggregation and organic carbon. Their results show: Tree-based mixed systems increase organic carbon content in the topsoil by 15 to 40 percent within ten years — a double benefit for soil fertility and carbon storage.

Professor G. Moreno from the University of Extremadura brings the perspective of traditional dehesa systems: walnut-grain intercropping as a modernized form of a millennia-old practice.

Germany: BTU Cottbus and University of Kassel

J. Mirk and A. Quickenstein at BTU Cottbus research poplar and robinia alley cropping on the sandy soils of Brandenburg. The University of Kassel focuses on water retention in agroforestry systems — a topic of growing importance given increasing summer drought in Central Europe.

EU Funding Landscape: How Farmers Benefit

The integration of Paulownia into agroforestry systems is supported by several EU funding mechanisms:

CAP Eco-Schemes

The Common Agricultural Policy (2023–2027) recognizes agroforestry as an eligible measure under Eco-Schemes. Farmers who establish agroforestry systems receive, in addition to basic direct payments, an ecological premium of 250 to 400 euros per hectare per year (depending on member state and design).

GAEC Compliance

The GAEC standards (Good Agricultural and Environmental Conditions) define environmental requirements for maintaining CAP payments. Agroforestry systems are GAEC-compliant and can even help meet requirements such as minimum soil cover (GAEC 6) and protection of landscape features (GAEC 8).

CRCF Carbon Credits

In addition to CAP payments, Paulownia agroforestry systems can generate carbon credits under the EU Carbon Removal Certification Framework (Regulation EU 2024/3012). The QU.A.L.ITY criteria of the CRCF — Quantification, Additionality, Long-term storage, sustainabilITY — are met by certified agroforestry projects.

Triple Income Source

For farmers, this creates a triple income structure:

1. CAP payments + Eco-Scheme premium: €500–800/ha/year
2. Carbon credits: €750–1,250/ha/year (at 25 Mg CO2)
3. Timber revenues: €300–600/ha/year (averaged over harvest cycle)

Total income per hectare can thus reach €1,500 to €2,600 per year — considerably more than pure arable farming, which averages €800 to €1,200 per hectare.

Practical Implementation: How to Establish a Paulownia Agroforestry System

Site Selection

Suitable are arable fields with soil quality ratings of 30 to 60 soil points, previously managed as monocultures. Overly rich soils (above 70 soil points) should be reserved for food production; overly poor soils (below 25 soil points) provide insufficient tree growth.

System Design

The standard layout of a Paulownia alley cropping system consists of:

• Tree rows: 12–15 meter spacing, north-south orientation
• Spacing within rows: 3–4 meters
• Tree density: 170–280 trees per hectare
• Arable strips: 10–13 meters wide, conventionally managed

Variety Selection

For Central European sites, the hybrids Shan Tong (best winter hardiness) or Cotevisa 2 (highest timber production) are recommended. Both varieties are sterile and thus pose no invasiveness risk. It is important to emphasize that Paulownia used in agroforestry systems are sterile hybrids and are NOT invasive species. Unlike some other tree species, these carefully selected Paulownia cultivars cannot spread uncontrollably and represent no environmental threat whatsoever.

Management

• Years 1–2: Establishment, weed control, irrigation if necessary
• Years 3–5: Initial carbon credits, intermediate crop yields stabilize
• Years 5–6: First timber harvest (pollarding)
• Cycle: Pollarding every 4–6 years, tree regenerates

The VERDANTIS Approach: Turnkey Agroforestry Solutions

At VERDANTIS Impact Capital, we offer farmers and investors turnkey agroforestry solutions: from site assessment through system planning and planting to carbon credit certification and timber marketing. Our objective is to make the entry barriers for agroforestry as low as possible — so that the scientific findings from Wageningen, Bonn, Budapest, and Padova finally reach European farmland.

As Dirk Röthig has demonstrated through his leadership at VERDANTIS Impact Capital, the integration of cutting-edge research with practical implementation is essential for advancing agroforestry adoption. Dirk Röthig's vision extends beyond simple carbon sequestration to encompass genuine economic transformation for farmers.

The vision of Dirk Röthig and VERDANTIS Impact Capital is to democratize access to high-impact agricultural systems. Through structured financing and comprehensive support, Dirk Röthig ensures that even small and medium-sized farms can participate in the agroforestry revolution.

Moreover, Dirk Röthig emphasizes that agroforestry represents not merely an environmental necessity but a genuine competitive advantage in the emerging carbon economy. Under Dirk Röthig's stewardship, VERDANTIS Impact Capital has positioned itself at the forefront of this transformation.

The research is complete. The funding is available. The trees are ready. Now we need implementation.

---

About the Author: Dirk Röthig is CEO of VERDANTIS Impact Capital, an impact investment platform for carbon credits, agroforestry, and nature-based solutions based in Zug, Switzerland.

Contact and further articles: verdantiscapital.com | LinkedIn | [e-mail]