Agroforestry in the Netherlands – Integrating trees on farms. How to get started with agroforestry in the province of North Holland?

Agroforestry, the deliberate integration of trees and shrubs with crop cultivation or animal production systems, is gaining increasing attention in the Netherlands as a sustainable and innovative form of agriculture. This article explores the concept of agroforestry, its various forms, its historical context in the Netherlands, and the process of implementing it on farms.

Michael den Herder, European Forest Institute, Yliopistokatu 6 B, 80100 Joensuu, Finland, michael.denherder@efi.int

 

In the ”Proeftuin Agroforestry Noord-Holland” (North Holland Agroforestry Pilot) project, four farmers, together with the North Holland Nature and Environment Federation (Natuur en Milieufederatie Noord-Holland), a landscape architect, and researchers from the Louis Bolk Institute, worked on integrating agroforestry into their farms. They jointly investigated everyone’s wishes, capabilities, possibilities (legal and regulatory), and needs. This raised questions about the technical and financial aspects of implementing agroforestry on a farm, as well as business strategy and design. Knowledge was gathered during this process, which can be found on the website www.landbouwmetnatuur.nl. The purpose of the EIP-AGRI Operational Group ”Proeftuin Agroforestry Noord-Holland” was to provide agricultural entrepreneurs with tools and guidance if they want to integrate trees and shrubs onto their farms. The goal is to accelerate the process they go through and make the choices clearer.

What is agroforestry and why does it matter?

Agroforestry combines the practices of agriculture and forestry to create integrated systems that offer numerous ecological and economic benefits. Also known as ‘boslandbouw’ or ‘agrobosbouw’ in Dutch, agroforestry is defined as: the intentional integration of woody plants (trees and shrubs) with the cultivation of crops or animal production systems, due to the intended benefits arising from the ecological and economic interactions. This definition highlights the diversity of agroforestry systems and emphasizes the purpose behind planting trees – to achieve ecological and/or economic advantages.

Diverse forms of agroforestry

Agroforestry can take many forms, ranging from integrating animals into forests to combining trees with horticultural crops. Integrating trees with grassland and livestock is also possible. Various combinations are possible between trees and other agricultural activities. Within an agroforestry system, the emphasis can vary. For instance, the focus might be on poultry farming with trees playing a supporting role, or conversely, on fruit or nut production with livestock providing supporting functions. A common system involves incorporating rows of woody plants within arable fields, known as alley cropping. This system can also accommodate temporary grazing. Furthermore, trees can be integrated without a direct economic function, serving instead to enhance biodiversity, strengthen the scenic value of the landscape, or improve animal welfare (ecosystem services).

Reintegrating old systems into modern agriculture

Agroforestry systems are not new to agriculture. Historically, trees were integral to the farming landscape, providing essential products such as fruit, nuts, timber, energy, and animal feed. Simultaneously, trees and shrubs delivered crucial ecosystem services, including windbreaks, shade for humans and livestock, and soil nutrient enrichment. However, many of these elements disappeared from the Dutch landscape during the past century due to land consolidation, scaling up of agricultural operations, and the availability of alternative food, feed, building, and energy products. Consequently, the ecosystem functions provided by trees were also lost.

Currently, various agroforestry systems are being redeveloped in the Netherlands, leading to creative business models, such as combinations of recreation, education, fruit production, and cooperative ventures where customers are members. Compared to the past, the emphasis is now much more on providing ecosystem services.

 

Implementing trees and shrubs: A step-by-step process

The purpose of the EIP-AGRI Operational Group ”Proeftuin Agroforestry Noord-Holland” was to provide guidance for agricultural entrepreneurs looking to integrate trees and shrubs onto their farms.

The planning process

The type of agroforestry system suitable for a specific farm depends on factors such as soil type, plot size, farm type, landscape, intensity, market opportunities, and the farmer’s own interests, skills, and ambitions. Designing a system can be a complex process due to the limited number of mature systems which can serve as an example how agroforestry can be applied in the Netherlands and the fact that successful agroforestry requires tailored solutions.

Steps in the process:

Step 1: Current situation

Assess the current farm setup, identifying what to maintain and what to improve.

 Step 2: Orientation phase

Define ambitions and goals for integrating trees and shrubs. Consider whether the primary aim is to enhance biodiversity, promote ecosystem services and animal welfare, or connect nature reserves. Alternatively, the goal might be to diversify production, explore new products like fruit or nuts, or integrate activities like recreation, care farming or education. Determining the main economic focus (trees, crops, livestock, or other activities) is essential. Also, decide on the scale of implementation, from small-scale integration to large-scale agroforestry. Do background research in the establishment, management, cultivation, and potential processing of products, and investigate market demand. When possible, seeking advice from existing agroforestry pioneers is highly recommended.

Step 3: Agro-ecological analysis and parcel location

The local environment significantly influences which tree species can thrive. Soil type, topsoil depth, and groundwater level are crucial factors. Observing existing tree species in the surrounding area can provide valuable insights.

Soil and hydrology: Utilize online resources like maps.bodemdata.nl and www.pdok.nl for information on soil and groundwater at the parcel level. Consult with local tree nurseries for species recommendations.

Landscape history: Investigate the historical land use of the parcels and surrounding area using resources such as www.topotijdreis.nl and www.kaart.cc. In the past, trees present in the Dutch agricultural landscape may have disappeared due to land consolidation.

Local nature objectives: Ensure that the chosen agroforestry system aligns with local nature and landscape objectives. Information on these objectives can be found at www.bij12.nl.

Land use designation: Check with the local municipality for land use designations and relevant regulations. www.ruimtelijkeplannen.nl provides access to spatial plans.

Agriculture and trees: Current Dutch regulations define agricultural land in a way that can limit agroforestry development, particularly regarding subsidies.

 Step 4: Sketching and designing:

Design complexity can vary. Designs often evolve as more knowledge is gained. Consult with specialized advisors, landscape organizations, nurseries, and fellow farmers. Consider ecological interactions between species, including competition for water, light, and nutrients, and allelopathy (chemical interactions between plants). Positive interactions, such as those found in permaculture plant guilds, could be encouraged, while negative interactions, such as the effects of juglone from black walnut trees reducing the growth of some sensitive crop species, should be avoided. Consider factors like water uptake and transpiration, interception of rainfall by tree canopies, wind reduction by hedgerows, and shading.

Step 5: From core activities to business model

Once the first four steps are completed, the future agroforestry activities will become clearer. Developing a viable business model requires defining target groups and customers, approaching strategic partners, and securing funding. This is especially relevant for systems involving trees that regularly yield a harvest. Consider the necessary investments for establishing and maintaining the system, including start-up costs, land preparation, plant material, tree protection, labour, and potentially machinery for harvesting, storage, and processing.

 

Agroforestry in Noord-Holland

Historically, small-scale agroforestry systems were common near traditional ‘stolpboerderijen’ (a type of Dutch farmhouse) in Noord-Holland, often involving silvopastoral systems with trees, grass, and sheep. The province predominantly consists of open arable and peat meadow areas with expansive views. Historically, livestock were contained by ditches rather than hedges. These open landscapes are vital breeding grounds for meadow birds, for which tree planting is not always desirable. Therefore, agroforestry does not support all forms of biodiversity.

However, there are areas in Noord-Holland where agroforestry is more suitable and can contribute to reducing wind erosion, such as in the inner dune areas where windblown fertile soil is a problem. These locations are often used for flower bulb cultivation. Integrating windbreaks can protect parcels from wind and create a favourable microclimate for crop growth. Elsewhere, trees can strengthen the agricultural system and positively impact the landscape and local biodiversity objectives.

Agroforestry and livestock farming

Silvopastoral systems, integrating trees and shrubs with grazing livestock, are a prominent form of agroforestry particularly in the Mediterranean area. These systems offer multiple benefits for livestock farming, from providing shade and shelter to improving pasture quality and offering nutritional supplements through fodder trees. Also in the Netherlands, silvopasture was traditionally practiced and some practices can still be found nowadays. Examples include orchard grazing, where poultry controls pests and fertilizes trees, and integrating livestock into young orchards or pastures with trees. Careful management, including protecting young trees from grazing animals, is crucial. Additionally, planting coppiced woodland like willow within chicken runs provides shelter and a sustainable source of materials for crafts like hurdle making, while also enhancing biodiversity. Some farmers also plant specific trees like willow in pastures as forage trees and a natural source of salicylic acid which has a pain relief effect for livestock.

 Agroforestry in arable and horticultural farming

Agroforestry also offers valuable applications in arable and horticultural farming. For example, Alley cropping. This system involves planting trees in rows with crops grown in the alleys between them. This method requires regular field operations and brings regular harvests. As the trees mature, the crops appear to be grown in long corridors. Temporary grazing of livestock can also be integrated into alley cropping systems. Animals like pigs can contribute to ploughing, while chickens can control weeds between the trees.

Forest farming focuses on making existing forests productive rather than adding trees to agricultural land. Examples include growing shiitake mushrooms on oak logs in the forest understory or allowing pigs to forage in the forest.

Riparian buffers are a widely used form of agroforestry which involves planting trees and shrubs along riverbanks to prevent erosion and nutrient runoff into surface water. Riparian buffers are valuable for achieving regional climate, water, and biodiversity goals. While not directly productive, they indirectly improve conditions for both agriculture and nature by preventing emissions to surface water, acting as windbreaks (reducing plant evaporation), and creating ecological corridors.

 

Tree species, functions, and products

A key principle in permaculture is that every element in the system (plants, animals, people) should serve multiple functions. Therefore, when integrating trees and shrubs, it’s crucial to select species that maximize these functions. For example, a fruit tree can provide fruit, shade, and shelter for chickens, while the chickens lay eggs and fertilize the trees. The location is also very important.

This section details various tree and shrub species suitable for agroforestry in the Netherlands, categorized by their ecological functions and preferred growing conditions:

Fast-growing species:

These species (willow, poplar, alder) thrive in relatively moist locations and help improve water infiltration and drainage. On drier sites, monitor for drought stress and competition for water between trees and crops. Willow and poplar can also be used for phytoremediation (removing heavy metals like cadmium from the soil).

• Willow (Salix spp.): Prefers moist soils and provides essential nectar and pollen for early spring bees. It can be used as fodder, shelter for outdoor animals, in hedgerows, as windbreaks, and for woodchip or short-rotation wood production. Coppiced willows are a characteristic landscape element in the lower parts of the Netherlands.
• Poplar (Populus spp.): Well-suited for wood production (for building materials and clogs) due to its rapid growth (harvestable after 30 years). Historically used in poplar meadows for grazing. Combines better with grassland than arable crops (mature poplars compete with root crops and maize for nutrients and water, although competition with grain crops is generally manageable).

Nitrogen fixers and mineral pumps:

These species enhance soil fertility by fixing atmospheric nitrogen or extracting specific minerals from the soil.

• Alder (Alnus glutinosa): Forms a symbiotic relationship with nitrogen-fixing bacteria. Its leaf litter is nitrogen-rich and benefits soil life. Alder grows relatively quickly and tolerates wet conditions, often planted along ditches to stabilize banks. Traditionally coppiced and provides shade and shelter for livestock.
• Robinia (Robinia pseudo-acacia): Also forms a symbiotic relationship with nitrogen-fixing bacteria, resulting in high protein leaf content. However, its bark and pods contain toxins, making it less suitable as fodder.
• Linden (Tilia spp.): Highly valued for its wood historically, now primarily planted near farms, villages, and cities. Its fragrant flowers attract bees and other insects. The young leaves are edible, and the leaves are rich in calcium, benefiting both livestock and soil life.
• Japanese silverberry (Elaeagnus umbellata): A hardy shrub tolerant of sea wind and salt, making it suitable for coastal areas. It also fixes nitrogen. It produces white flowers and berries suitable for jams.

High sandy soils:

Species like birch, oak, sweet chestnut, sea buckthorn, cherry, and plum thrive on these soils, as do some apple and pear varieties (with appropriate rootstocks). Young trees on sandy soils are vulnerable to drought and require regular watering in the initial years.

• Sweet chestnut (Castanea sativa): Widely cultivated in France, northern Spain and Italy for its nuts (eaten directly or processed into flour and jam). Can grow into large shade trees that also produce a harvest.
• Birch (Betula spp.): Native to the Netherlands. Birch sap can be tapped in spring. Provides light shade for grazing livestock. Its pollen is highly allergenic.

Salty conditions:

Some species tolerate salty soils, including sour cherry and sea buckthorn.

• Sour cherry (Prunus cerasus): Primarily cultivated for its fruit used in products like beer and juice. Also found in wild form in forest edges.
• Sea-buckthorn (Hippophaë rhamnoides): Native to calcareous dune areas. Fast-growing and drought-tolerant. Fixes nitrogen and its orange berries are rich in vitamin C and used in jams.

Songbird shrubs:

Shrubs like hawthorn, dogwood, alder buckthorn, elder, and dog rose provide important habitat for songbirds in open areas. A diverse hedge also attracts beneficial insects. Hawthorn can form impenetrable livestock barriers.

Fodder trees and hedges:

A diverse hedge of trees and shrubs can provide a natural supplement of minerals and trace elements for livestock. It’s important to manage access to fodder trees to allow for regrowth. Fast-growing species are preferable, and keeping trees in shrub form makes young twigs accessible to animals.

Fruit cultivation:

Most fruit trees thrive on clay and loamy soils with good drainage. Specific rootstocks and varieties are available for sandy soils. Cross-pollination is often necessary, requiring pollinator trees. Fruit trees are typically grafted. Rootstock influences tree vigor. There is a choice between low-stem, half-stem or high-stem trees. High-stem orchards are well suited for grazing (orchard grazing).

Nut cultivation:

Nut growing is a small sector in the Netherlands. However, the popularity of regional nut production is increasing.

• Walnut (Juglans regia): Not native but historically planted near farms and along dikes. Cultivars with late flowering are best to avoid frost damage. Walnut trees require well-drained soil and cross-pollination. Different varieties are needed for cross-pollination to occur. Walnut is often combined with other crops or animals due to the long time it takes to produce a harvest. Juglans nigra is the best choice for timber production.
• Hazelnut (Corylus avellana): Native to the Netherlands. Wild variants are suitable for hedgerows and as fodder trees. Hybrid varieties produce more nuts. Hazelnuts thrive on various soil types (pH above 5) with consistent moisture.

Conclusion

Agroforestry offers a promising pathway towards more sustainable and resilient agriculture in the Netherlands. By carefully considering the local context, planning thoroughly, and learning from existing examples, farmers can successfully integrate trees and shrubs into their farming operations, reaping both ecological and economic benefits.

 

About the FOREST4EU project

This article has been produced in the FOREST4EU project as a part of capacity building materials directed to stakeholders across Europe. Whereas innovations developed in the operational groups are typically available locally, FOREST4EU project aims at transferring knowledge and best practices on forestry and agroforestry to stakeholders and operational groups across Europe. The article in a printable PDF format: https://www.forest4eu.eu/wp-content/uploads/2025/02/Agrof.Netherlands_EFI_FIN.pdf

 

Kuva: Willow coppice, the Netherlands. Michael den Herder, AGFORWARD project, July 2011, CC BY-NC-SA 2.0.

Sources

Boki Luske, Evert Prins, Erna Krommendijk, Nienke Geerts. 2020. Agroforestry op het Landbouwbedrijf – Bomen en struiken inpassen. Hoe pak je dat aan in Noord-Holland? Louis Bolk Institute, the Netherlands. Available online at: https://www.landbouwmetnatuur.nl/wp-content/uploads/2020/12/LBI-brochure-Agroforestry.pdf

Further information

Getting started with agroforestry [Aan de slag met agroforestry]: https://www.mnh.nl/project/proefpercelen-agroforestry/

Food forests and agroforestry [Voedselbos en agroforestry]: https://www.mnh.nl/project/voedselbossen-en-agroforestry/

Knowledge Hub Nature-Inclusive Agriculture [Kennispunt Natuurinclusieve Landbouw]: https://www.landbouwmetnatuur.nl/

Michael den Herder