What are the concepts of agroforestry

economically and ecologically attractive with paulownia

With the key words Agroforestry or Agroforestry systems is currently developing in agriculture new trendwhich, however - at least in Germany - is currently still a tender plant. Actually only what belongs together is brought together here. This not only offers in more ecological, but also in economic terms - especially in connection with Kiri - tangible advantages. They are against it Disadvantages relatively minor or even negligible. That is why the Future of agroforestry systems in general and with paulownia especially bright.

What exactly is agroforestry?

Actually, agroforestry is not entirely new. Rather, it is rooted in a centuries-old practice that is now being applied more systematically. This is the combination of meadows, pastures or arable crops on the one hand and woody plants on the other on an area. It is therefore a form of intercropping. Because intercropping generally aims to derive advantages from the cultivation of different crops in the immediate vicinity. As early as the Middle Ages, farmers used the cutting back of trees in or on fields as a source of fodder as part of the Schneitelbaumwirtschaft, used tree fruits such as acorns for animal fattening, created orchards or obtained energy wood for the local stove from trees planted on the edge of the field.

But from the end of the 19th century, fewer and fewer farmers were using these agricultural systems. The main reason was the greater intensification and mechanization of agricultural processes. Trees and bushes stood too much in the way of the growing agricultural machines that were supposed to harvest fields faster and faster. Only in the form of windbreak hedges can be found today more often on the edge of fields and meadows. Even orchards have not yet completely disappeared from the landscape.

But soon these sustainable systems of land use could shape agricultural landscapes more strongly again. There are several reasons for this. Agroforestry and intercropping now often explicitly take into account the requirements of modern agricultural technology in the form of agroforestry systems. In this context, it is common not to distribute the trees over the field, but to plant them in strips. As a result, trees and bushes disrupt agricultural use as little as possible. At the same time, many modern agricultural machines can now be used so flexibly that individual trees or bushes no longer represent a relevant impairment.

What are the advantages of agroforestry systems?

Agroforestry systems offer a variety of advantages that not only benefit our environment, but often also pay off in monetary terms. In this way, areas next to or under trees can be used not only for keeping livestock, but also for arable crops. The trees and bushes specifically bind climate-damaging carbon dioxide that would otherwise escape into the atmosphere. This effect is particularly great with trees - such as paulownia - which are made from first-class logs or valuable wood. The growth of paulownia wood per hectare and year binds around six tonnes of additional carbon dioxide as part of our “Grassland Plus” concept. At the same time, trees and shrubs increase and secure biodiversity by providing habitats for numerous animal and plant species. Paulownia, for example, is a popular tree for bees.

Agroforestry systems also pay off financially. In this way, energy wood, trunk wood or valuable wood can be obtained from trees, depending on the type and harvest time. Paulownias are particularly attractive here. Because these trees not only grow quickly, but also come out of the roots again after the harvest. This makes the tree suitable both for the rapid extraction of energy wood and for the long-term harvest of valuable wood. Thanks to our “Grassland Plus” concept, the contribution margins of the grassland can be increased by around € 2,000 ha / a.

Because the roots of the kiri grow quickly deep into the ground, they also provide important protection against erosion, which is particularly important on slopes. In addition, woody plants improve the microclimate and have a positive influence on the supply of nutrients and water in the area. They not only provide shade and thus minimize water evaporation, so that the neighboring arable plants can also better survive periods of drought. Nutrient-rich biomass - which consists of dead leaves, wood and roots - also increases the fertility of the soil. In this context, trees with deeper roots such as the kiri even function as real pumps for water and nutrients from the lower soil regions. As a result, agroforestry with suitable trees not only delivers more constant, but also higher yields overall.

Studies also indicate that agroforestry systems are suitable for protecting groundwater and improving its quality - for example with regard to a lower nitrate concentration. In this sense, with their biomass, they serve as a kind of protective shield that prevents or at least reduces the transfer of harmful substances into water. In addition to the economic and ecological advantages of agroforestry, there are other arguments that cannot be categorized into either of these two categories. Many people often find the planting of trees and bushes pleasant and see them as a welcome ornament for the landscape that increases the perceived quality of life.

What are the disadvantages of agroforestry systems?

Even if the various advantages of agroforestry systems usually significantly outweigh their potential disadvantages, the latter cannot be disputed away. When making a decision for or against agroforestry, these should definitely be taken into account in advance. Agroforestry systems inevitably cause costs, especially at the beginning, which only pay off in monetary terms after a few years. In this context, it is necessary to tie up not only areas for planting, but also capital in the long term. This reduces the flexibility with regard to leasing or selling the space. However, initial costs, capital commitment and reduced flexibility are characteristics that are typical of a large number of investment projects.

In addition, more work is required for the management and maintenance of the additional biomass from trees or bushes. However, this effort is mainly incurred in the winter months, when less agricultural work is usually necessary. In addition, the kiri in particular is very easy to care for. Any problems related to the competition between several plants for light and space can also be minimized or even completely avoided through competent planning and management.

What does the present and future of agroforestry look like?

The interest in the subject of agroforestry has been increasing steadily for several years. The reason for this is likely to be greater awareness of the negative consequences of climate change and the threat of losses in the area of ​​biodiversity. Nevertheless, there are currently relatively few agroforestry systems in Germany. This is probably due to the fact that there are no subsidies in the Federal Republic of Germany, with the exception of the “orchards with grassland use” system. However, that should change soon. Because several regulations of the European Union already deal with agroforestry systems. The member states must implement these into national law. France is already further ahead than Germany and grants identical payments for strips of trees and arable crops. In non-EU countries like Switzerland, there has even been funding for agroforestry for more than two decades. So it should only be a matter of time before Germany too offers corresponding subsidies for sustainable agriculture and thus takes a big step forward in climate protection and the conservation of biodiversity.

See also: (Final report of the agroforst project; University of Freiburg)