Agroforestry

Agroforestry or agroforestry (English Agroforestry or Agroforesting ) refers to a production system, the elements of agriculture combined with those of forestry.

Both perennial trees ( eg fruit trees, palm trees, timbers ) and annual agricultural crops are integrated on the same surface. In addition, when livestock farming on the same land, one speaks of agrosilvipastorilen systems. An example of this is the Dehesa, a system that cork trees, piggery and agriculture combined, and is widely used in Extremadura in western Spain. In the culture tree farms of the Sudanese savannah trees high value in use, such as baobab, shea butter tree and Néré be planted directly, but exempt from the clearing, including mostly planted sorghum or corn.

Agroforestry systems are considered, especially in areas that are naturally covered by tropical rain forest as ecologically beneficial. They are rich in species, stabilize the water balance and protect the soil from erosion. However, the marketing of the products is often difficult due to their abundance and low levels, which impairs the efficiency of such systems.

Research in Europe

An EU research program has in recent years also for Europe with the possibility of combining one year of arable crops and tree crops (with very long rotation ) were employed. The researchers came to the conclusion that significant additional income of up to 30 % can be realized through agroforestry. The production of a cultured with a mixture of poplar and wheat area of ​​one hectare corresponds to the production, only possible with a space consumption of 1.3 ha would be a separate attachment ( 0.9 ha wheat and additional 0.4 ha poplars ). Successful in doing so is the combined agroforestry system in the simultaneous cultivation of nitrogen-fixing woody plants and crops. Partly this the trees are planted in rows ( with three, four or even ten meters distance ); agricultural crops are grown in such an "alley cropping " in the interstices.

The World Agroforestry Centre in 1978 (then the International Centre for Research in Agroforestry, ICRAF ) founded to research and information exchange on agroforestry to promote. It aims to contribute to poverty reduction and food security through ecologically sound production methods. Also at the French Institut national de la recherche agronomique a research group is located. In the UK, in particular the Agroforestry Research Trust and its director Martin Crawford mentioned. In Germany there are groups of researchers at the Albert- Ludwigs- University of Freiburg, the Georg-August -Universität Göttingen and Dresden.

Within the framework of the European Agricultural Fund for Rural Development Area ( EAFRD ) first promoted establishment of agroforestry systems on agricultural land (see there Art. 44).

Benefits

• Habitat for animals ( predators and pests, the greater the biodiversity, the more " stable " is often an ecosystem ).
• Reduction of soil erosion of a field by the wind resistance of trees ( thus also to reduce evaporation; much wind = a lot of evaporation).
• At the same time the trees and their roots help the penetration of water into the soil and thus contribute to the fight against water erosion. They also help to prevent flooding by minimizing runoff after rainfall, and may contribute to lower water pollution by agricultural fertilizers.
• Supply of shadow, which (combination of pasture land with trees ) the protection and comfort of the animals used in mixed livestock in summer. At the same temperature even by the shadow of the soil, especially in summer, which in turn leads to reduced evaporation ( only for larger trees possible; important factor in dry areas ).
• Supply of free fertilizer (ie little or no purchase of fertilizer ), as trees ( depending on species) with their deeply anchored in the ground roots pumping plant nutrients up and after leaf fall, these nutrients in turn to the upper soil layer and thus dispose to the there -rooting crops. Moreover, since this natural fertilizer is better suited for the soil fauna ( excited ), this is strengthened and then in turn provides a better soil quality (keyword crumb structure ).
• Cooling in summer by the significant effect of evaporation over the leaves of the tree (as above limitation by size of the trees). The roots can also carry up from deep water layers of water. Plants are thereby protected against too strong heat stress (keyword hot summer of 2003 ). Also, the soil life does not tolerate excessive heat and can therefore longer participate in the improvement of soil structure.
• Looking at the life cycle of a tree, the farmer can achieve through the sale of wood ( veneer as burning or timber ) a much larger profit than in a pure agricultural or forestry use a pure.
• Trees that are grown in agroforestry systems, are much lighter than achievable in a wooded area and which can therefore be more easily maintained and "harvested".
• Since the rows of trees are relatively far apart, these trees get much more light than within a forest. In addition, this favorable situation exists throughout their lives. Thus, the trees grow very uniform in contrast to a normal forestry maintenance, repeatedly trees are removed from a tree at the Community and thus lead to growth spurts in the neighboring trees. This results in a fine and uniform grain of the wood, which not only looks beautiful but also simultaneously to a greater strength of the timber (keyword timber ) leads.
• Recently also beautify the landscape image which acts appealing than monotonous monoculture areas. For example, bicycle tourists who come to such a field, the value many shadow areas.

Disadvantages

• The variety of products in each of relatively small amounts difficult to market and thus increases the transaction costs for producers.
• Farmers have to deal with many additional topics related to the rearing of trees or further education (rearing, pruning, felling, marketing).
• The rearing of trees means an increased workload per hectare field area and year. This also includes some larger shunting for harvesting machines in the combination of crops and trees.
• Since the trees can be "harvested" only after a certain age, this may initially also mean a loss per hectare under certain conditions. The positive aspects of trees, that is, the additional benefits that may offset some of the loss, do not become apparent until after a certain age.