The decreasing incomes of farmers, the overproduction of agricultural commodities and the increasing pressure o­n agricultural land requires o­ne to take a wider view and to search for alternative crops and sustainable multiple land use system in The Netherlands. Agroforestry, the production of trees and crops and/or livestock o­n the same plot, may be an answer. Research indicates that agroforestry systems are very efficient in terms of resource use and could introduce an innovative (agricultural) production system that will be both environmentally friendly and economically profitable.

To get insight about the potential of modern agroforestry in The Netherlands, where currently agroforestry plays almost no role, a holistic study approach was taken, assessing the ecological, technical and socio-economic aspects of agroforestry. As part of the Silvoarable Agroforestry For Europe (SAFE) project, a survey was carried out to investigate the attitude of Dutch land users towards agroforestry and to assess the conditions of acceptability of new agroforestry systems. In January 2004, the interviews were held with 27 farmers and 2 estate owners in two rather different regions in The Netherlands, namely the Achterhoek and North-Friesland. In addition, a literature research of the main agroforestry practices that would be appropriate and innovative were identified, the advantages and disadvantages of agroforestry related to the situation in The Netherlands were reviewed and a selection was made of tree and intercrop species that have proven their value in temperate agroforestry and/or are expected to be promising under Dutch conditions. Finally, based o­n website-information of the ministry of LNV (Agriculture, Nature Conservation and Fisheries), an overview was made of the restrictions of the Dutch forest law and of governmental subsidies, which may be eligible for agroforestry.

Four distinct agroforestry practices are considered to be appropriate and innovative for The Netherlands:

1. Silvoarable agroforestry, comprising widely-spaced trees and/or shrubs associated with arable crops
2. Silvopastoral agroforestry, a combination of trees, forage (pasture) and livestock production
3. Forest gardening, comprising multi-species and multi-storied dense plant associations, planted and/or managed in such way that they mimic the structure and the ecological processes of natural forests
4. Forest farming, the cultivation of edible, medicinal or decorative specialty crops as under-storey in (semi)natural woodlands

There is a variety of tree species that would fit in such practices in The Netherlands and provide wood and/or secondary products. Potential tree species are:

• multipurpose trees that have proven their value and their suitability to the Dutch environment, e.g. walnut (Juglans spp.), chestnut (Castanea sativa), hazelnut (Corylus spp.), sweet cherry (Prunus avium) and other fruit trees
• trees with fast (juvenile) growth, which may be suitable for short- and mid-term rotations (< 50 years), e.g. poplar (Populus spp.), willow (Salix spp.), alder (Alnus spp.), ash (Fraxinus excelsior) and maple (Acer spp.)
• multipurpose species that are not yet cultivated o­n a commercial scale in The Netherlands, but have a potential for Dutch agroforestry mainly due to their secondary products, e.g. honeylocust (Gleditsia triacanthos), hawthorns (Crataegus spp.), russian olive (elaeagnus spp.), buckthorn (Hippophae spp.), strawberry tree (Arbutus unedo), mulberry (Morus spp.) and other "specialty trees".

In The Netherlands, o­n the long term, the cultivation of common light-demanding crops in agroforestry systems may not be beneficial, because sub-optimal light conditions may seriously reduce crop yields or may cause problems with grain ripening. At this point, replacement of the light demanding crop by shade-tolerant forages and pastures may be considered. Livestock may benefit from the shelter provided by trees, but (young) trees need to be well protected to prevent damage.

There is a broad range of interesting alternatives, which can produce valuable products in the (partially) shaded alleys, both o­n a large scale for the bulk market and o­n a smaller scale for certain niche markets. Many of these are new for The Netherlands and require further research to assess their potential for agroforestry applications. Examples are:

• small-fruit species as Vaccinium spp., Ribes spp., Rubus spp., Actidinia spp. and various other berry species
• specialty crops as ornamental species, medicinals, specialty vegetables and gourmet mushrooms
• non-food crops for fiber and biomass production, as hemp and willow short rotation coppice

Small fruit species and specialty crops are particularly suitable for cultivation in forest farming and forest gardening systems. Crops for fiber and biomass production seem to have good prospects and show high potential for agroforestry applications, in particular o­n intensive farms. Instead of leaving tree strips in silvoarable and silvopastoral systems bare or fallow, they could also be grown with a shade tolerant or specialty crop o­n the tree strip, e.g. Christmas trees, fruit shrubs, flower bulbs, decorative florals, mushrooms and flowers for honey production.

Notwithstanding the promising opportunities of agroforestry, there are some formidable constraints that prevent the realization of the potential benefits. A major constraint is institutional. Agroforestry is not recognized as an official land use class, and therefore agroforesters can neither receive the grants for forestry plantations, nor those for agricultural crops in agroforestry systems. National laws oblige farmers to harvest trees before age 40 to prevent agroforestry plots shifting to a forest status and considerably decrease in value.

Local regulations may impede the planting or felling of trees or force farmers to replant trees after felling. Until now, there has been little attention (and funding) for agroforestry in Europe and The Netherlands. The lack of an adequate research base, practical demonstrations and extension agents and advisers who are able to address agroforestry issues hampers the development of agroforestry, as farmers and other land users often lack the knowledge and skills. At present, o­nly large farms may be able to bear the investment costs for tree establishment, unless subsidies are provided for the smaller o­nes. Apart from the fact that most land users in The Netherlands are not aware of the possibility of agroforestry as an alternative land use system, few will be inclined to adopt it as long as the financial benefits are not proven and demonstrated. Applied research, practical demonstrations and institutional support are recommended to develop agroforestry o­n a large scale and to realize the benefits it offers. Although the concept is new for them, farmers in The Netherlands have indicated to be interested in agroforestry as an alternative land use system, if it is shown to be economically viable in The Netherlands. In the Achterhoek, farmers are more open to agroforestry than in Northern Friesland, possibly because decreasing farm profits in the sandy areas and the limits to further intensification force farmers in this region to take a broader view o­n agriculture. Furthermore, they already have experience with trees and are more open to cooperation with neighbors and landlords.

Farmers in both regions see a lot of negative aspects of agroforestry, mostly technical such as mechanization, labor, and lower revenues o­n the intercrop. Most farmers emphasize the need for subsidies to compensate for the losses o­n the revenues of the intercrop and the expected extra costs for labor and tree maintenance. Another constraining factor is the lack of knowledge o­n tree management, tree returns and the market for tree products. Since most farmers have the experience to gain little or no money by the sale of tree products, they have little confidence in the profitability of agroforestry. Since farmers have little or no experience with growing trees and agroforestry in particular, they find it hard to decide how they would design an agroforestry system. Farmers pointed out they need much more background information and practical examples to make reasonable decisions.

In the survey, 62% of the respondents in the Achterhoek said they would like to try an agroforestry project, while o­nly 27% of the Friesian farmers were enthusiastic to try an agroforestry project. Whether respondents would adopt agroforestry would not so much depend o­n respondents� age, but rather o­n profitability, the subsidies and o­n the (availability of a) successor. To develop agroforestry in The Netherlands, first the aforementioned structural constraints should be addressed. Policies should recognize agroforestry as a legal land use status and adapt grant regulations and laws accordingly. Research and extension should get more acquainted with agroforestry, prove its benefits in The Netherlands and share this knowledge with farmers. Eventually, agroforestry systems should be designed, which take into account the technical, ecological and socio-economic constraints and opportunities and the objectives of different land users.

By Michel Postma, Group Plant Production Systems, Department of Plant Sciences, Wageningen University