What is agroforestry ? > Introduction
is an activity that combines production on the same plot of land, from
annual agricultural activities (such as crops and pasture) and from delayed
long-term production by trees (for example timber and services). This
is obtained either by planting trees on agricultural land or by cropping
(for example after thinning) on forested land. Plots that combine arable
intercrops with forestry trees are silvoarable plots, while wooded plots
with pasture under the tree canopy are known as silvopastoral plots.
and walnut agroforestry plot
(Restinclières - France)
advantages of agroforestry
provides a different land use option, compared with traditional arable
and forestry systems. It makes use of the complementarity between trees
and crops, so that the available resources can be more effectively exploited.
It is a practice that respects the environment and has an obvious landscape
benefit. Efficient, modern versions of agroforestry have been developed,
that are adapted to the constraints imposed by mechanisation. The agroforestry
plot remains productive for the farmer and generates continuous revenue,
which is not the case when arable land is exclusively reforested. Agroforestry
allows for the diversification of farm activity and makes better use of
environmental resources. Agroforestry has interesting advantages from
three different perspectives.
the arable perspective
of the activities of arable farmers, with the building-up of an inheritance
of valuable trees, without disrupting the revenue from those plots which
have been planted.
of intercrops and animals by the trees, which have a windbreak effect,
providing shelter from the sun, from the rain, from the wind, holding
the soil in place, and stimulating soil microfauna and microflora
of some of the leached or drained nutrients by the deep roots of the
trees; enrichment of the soil organic matter by tree litter and by the
dead roots of the trees.
of combining the interest of the owner (for an inheritance of wood)
and the farm (for access to cultivated land). Possible remuneration
for the arable farmer for looking after the trees
- An alternative
to full reforestation of arable land, permitting the continuation of
arable activity on land whose arable potential is therefore conserved.
The tree component can be reversed, the plot stays "clean"
(free from scrub) and is easy to destump when the trees are clear felled
(the stumps are in lines and few in number).
- In silvopastoral
plots, fodder units can be available at different dates compared to
full cropped plots, extending the grazing calender.
harvest in a poplar agroforestry plot (Vézenobres - France)
of the diameter growth of the trees by wide spacing (+80% over 6 years
in the majority of the experimental plantations). Reduction of the capital
cost of the plantation, by reducing the number of trees planted with
no commercial future. A large reduction in the maintenance costs of
the plantation, due to the presence of the intercrops.
in the quality of wood produced (wide regular rings, suited to the needs
of industry), because the trees are not subjected to cycles of competition
follow-up and tree care due to the arable intercropping activity. In
particular, protection against the risk of fire in susceptible areas,
with pastoralism or with intercrops like vine or winter cereals (clear
bare ground in summer after stubble ploughing).
plantations on arable land allow the development of a quality wood resource
that complements, rather then competes with, the products from traditionally
exploited forests. It is especially important to produce wood that can
substitute for tropical sawlogs, which will soon decline in availability
and quality. The areas concerned will remain small in terms of their
absolute value, but the production of wood from them could become a
critical input to the European wood supply network. Tree species that
are little used in forestry, but are of high value, could be grown in
agroforestry systems: service trees, pear trees, common sorbs, walnut
trees, wild cherry trees, maple trees, tulip trees, paulownias, etc
to the development of natural resources: the total wood and arable production
from an agroforestry plot is greater than the separate production obtained
by an arable-forest separate cropping pattern on the same area of land.
This effect results from the stimulation of complementarity between
trees and crops on agroforestry plots. Thus, weeds, which are spontaneously
present in young forestry plantations are replaced by harvested crops
or pasture; maintenance is less costly and environmental resources are
control of cultivated areas of land: by substituting for arable plots,
the agroforestry plots contributes to diminishing the cultivated area
of land. The intensification of environmental resource use by agroforestry
systems is not resulting in more crop products.
of original landscapes that are attractive, open and favour recreational
activities. Agroforestry plots have a truly innovative landscaping potential,
and would improve the public image of farmers to society. This will
be particularly the case in very sparsely wooded areas, where plots
are developed by planting arable land, and in very heavily wooded areas,
where plots are developed by thinning the existing forest.
the greenhouse effect: constitution of an effective system for carbon
sequestration, by combining the maintenance of the stock of organic
material in the soil (the case especially with meadows), and the superimposition
of a net fixing wooded layer.
of soil and water, in particular in sensitive areas.
of biodiversity, especially by the abundance of "edge effects".
This in particular, permits a synergistic improvement, by favoring the
habitat of game. The integrated protection of crops by their association
with trees, chosen to stimulate the hyperparasite (parasites of parasites)
population of crops, is a promising way forwards.
favorable characteristics are as coherent with the many objectives of
the laws guiding agriculture and forestry, as they are with the directing
principles of the Common Agricultural Policy.
Young walnut trees in lavanda plot