Climate-friendly practices applied: Agroforestry
During the past three decades, agroforestry has become recognized as an integrated approach to sustainable land use because of its production and environmental benefits. It is recognized as a greenhouse gas mitigation strategy and has great potential as a strategy for biological carbon sequestration. The perceived potential is based on the premise that the greater efficiency of integrated systems in resource (nutrients, light, and water) capture and utilization than single-species systems will result in greater net C sequestration.
At the various SOLMACC farms agroforestry elements exist as shelterbelts of one or more rows of trees planted, as riparian buffers to filter surface run-off, protect stream banks and shorelines from erosion, as alley plantings in single or grouped rows and with agricultural crops grown in alleys between tree rows.
Read about how SOLMACC farmers in Germany, Italy and Sweden implement this practice and which challenges some of them are facing.
Agroforestry on the Bioland farms Kornkammer Haus Holte and Hofgut Krauscha
In summer 2015, a tree inventory was conducted at the two German farms Kornkammer Haus Holte near Witten, and at Hofgut Krauscha near Görlitz. To ease the inventory, the agroforestry sites as defined by aerial photographs as landscape elements for the EU agricultural subsidy scheme were characterized on-ground by identifying tree species and measuring wood biomass following specific allometric functions. It turned out that both farms contain significant areas planted with trees and hedgerows on non-forest land, which encompasses 5.71 and 11.37 ha at Kornkammer Haus Holte and Hofgut Krauscha, respectively. Determination of carbon stock in wood biomass and the underlying soils revealed that both farms possess a significant carbon sink on their farm premises with 5515t and 16089t CO2 equivalents at Farm Kornkammer and Hofgut Krauscha, respectively. For calculating C sequestrations in trees and hedgerows the new planting activities and the use of woody biomass are taken into consideration. These analyses are on-going.
Agroforestry on the Bioland farm Kreppold
With the support of their advisor and the scientists from FiBL the farmer on the Bioland farm Kreppold in Bavaria installed hedgerows and tree strips on some of their fields. About 6 ha of forest on the farm areal comes in addition to these newly planted trees and shrubs.
The farms’ woody biomass is used variously. Part of the woody biomass is used for setting up their composting mixture where it provides an important contribution for the compost ventilation. Another part is used for producing wood chips for the farms’ house heating system.
In Sweden, the SOLMACC farms are implementing four different agroforestry practices: alley cropping, silvopasture, riperian buffer zone and windbreak/diversity plantings. In this newsletter we focus on the first two practices.
Agroforestry on the Hånsta Östergärde farm
The farm has installed a 200 meter alley cropping system with four rows with woody crops and the farms normal crop rotation in the alleyways between the rows. Woody crops were primarily chosen to be of known commercial value and proven to grow well under the local climate. Since the farm already has large areas of forest land for timber and biomass production, our focus was on crops for food production. The chosen crops are saskatoon, sea buckthorn, apples, pears and hazelnuts.
Next to the design and species selection, alley cropping projects face the challenges of proper soil preparation, managing weeds, protection the plants from animal browsing and wind and making sure they get enough water during the first growing season.
At Hånsta Östergärde, ground preparation was done in the spring through plowing with a special farm designed subsoiler attached to the plow and then an ordinary rotary tiller to prepare the planting bed. A drip irrigation system was installed on three of the rows. Weeding was done manual during the first season.
Apple and pear trees were protected with individual wire cages made out of chicken wire. The rest of the crops were left unprotected since heavy browsing from wild animals was not expected. We did however loose some plants of these crops primarily to hares. During the summer we therefore decided to install a net fencing around the whole area in order to prevent major winter damages.
In the future a regular pruning of lateral roots along primarily the apple and pear rows is planned in order to reduce competition between trees and annual crops.
A great illustration of the effect can be found here http://www.agroforesterie.fr/phototheque/fichier-general/taille-800px/agroforesterie-dessin-trogne-systemes-racinaires-arbre-et-cultures-david-dellas.jpg
Agroforestry on the Trägsta Gård farm
At Trägsta Gård the SOLMACC project is working with developing and improving an existing silvopasture area of approximately 8 hectare. The area was a mixture of open formerly tilled land, traditional grazing land and forest land. The border fencing was in bad condition. It was grazed by only sheep.
The goal for the developing plan was to boost the growth of grass and other grazed plants through selective thinning of existing trees together with improved grazing practices. Sheep and cows will now both graze the area in a rotational setup.
Existing woody vegetation was primarily birch, scots pine, spruce and alder. When thinning the trees with the highest future value are saved. The timber value of the scots pine can be improved further by pruning the lower branches on young trees.
Challenges involves setting up new modern fencing which is labour intensive. The thinning operation also involves a lot of manual labour. Some of the thinned material can be used for pulp biomass or firewood, but it’s not cost effective to handle it manually. Luckily the farm owns a mini forest harvester which are able to work in very tight spacing and extract timber with minimal minimal soil damage.
Agroforestry on the Fontanabona farm
About 7% of the farm’s area is affected by hedges or permanent grasslands and in this 7 % there are Sycamores, willows, poplars, ash and Robinia, that go from 13 to 60 years of age, trees that are typical of the marginal areas of the farms in the area. There are also some fruit trees (peach, apple, apricot and cherry). Hedges and trees are mainly concentrated in two border areas. Another element of biodiversity is represented by an Actinidia plant which superiorly delimits the area invested in greenhouses.
Agroforestry on the Caramadre farm
The area is entirely surrounded by high trees typical of the Roman coast and in particular pine trees and eucalyptus. The latter also has a windbreak, particularly persistent in the area.
Agroforestry on the Mannucci Droandi farm
There is a rich natural biodiversity due to the presence of forests in the farm, in the border of the fields. The local woods are made up principally as from oak, ilex, elm, cypress, locust, pine, which generally are cut every 20 years.