Agroforestry - AbsoluteAstronomy.com

Agroforestry is an integrated approach of using the interactive benefits from combining trees and shrubs with crops and/or livestock.
It combines agricultural and forestry

Forestry

Forestry is the interdisciplinary profession embracing the science, art, and craft of creating, managing, using, and conserving forests and associated resources in a sustainable manner to meet desired goals, needs, and values for human benefit. Forestry is practiced in plantations and natural stands...

technologies to create more diverse, productive, profitable, healthy and sustainable land-use systems.

Definitions

According to the World Agroforestry Centre, Agroforestry is a collective name for land use

Land use

Land use is the human use of land. Land use involves the management and modification of natural environment or wilderness into built environment such as fields, pastures, and settlements. It has also been defined as "the arrangements, activities and inputs people undertake in a certain land cover...

systems and practices in which woody perennials are deliberately integrated with crops and/or animals on the same land management unit. The integration can be either in a spatial mixture or in a temporal

Temporal logic

In logic, the term temporal logic is used to describe any system of rules and symbolism for representing, and reasoning about, propositions qualified in terms of time. In a temporal logic we can then express statements like "I am always hungry", "I will eventually be hungry", or "I will be hungry...

sequence. There are normally both ecological

Ecology

Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...

and economic interactions between woody and non-woody components in agroforestry.

In agroforestry systems, trees or shrubs are intentionally used within agricultural systems, or non-timber forest products

Non-timber forest products

Non-timber forest products are considered as any commodity obtained from the forest that does not necessitate harvesting trees. It includes game animals, fur-bearers, nuts and seeds, berries,...

are cultured in forest settings. Knowledge, careful selection of species and good management of trees and crops are needed to optimize the production and positive effects within the system and to minimize negative competitive effects.

In some areas, a narrow definition of agroforestry might simply be "trees on farms." Hence, agroforestry, farm forestry and family forestry can be broadly understood as the commitment of farmers, alone or in partnerships, towards the establishment and management of forests on their land. Where many landholders are involved the result is a diversity of activity that reflects the diversity of aspirations and interests within the community.

Silvopasture

Silvopasture is the practice of combining forestry and grazing of domesticated animals in a mutually beneficial way. Advantages of a properly managed silvopasture operation are enhanced soil protection and increased long-term income due to the simultaneous production of trees and grazing...

combines livestock grazing on forage crops or pasture within actively managed tree or shrub crops. Cattle, sheep and goats are the most common livestock incorporated into silvopasture systems and they may be deployed entirely within a private farm/woodlot silvopasture or through collaborative arrangements between forest licensees and livestock producers on public lands (e.g. in British Columbia, sheep grazing is used as a vegetation management tool in young forest plantations).

Pinus radiata planted in 1970 in rows approximately 30 metres apart mid-spring. The trees averaged ~33 cms/13 inches in height at time of planting. To maintain productivity in the paddock, hay was harvested and then cropped the following autumn with oats. After this crop was harvested Merino

Merino

The Merino is an economically influential breed of sheep prized for its wool. Merinos are regarded as having some of the finest and softest wool of any sheep...

lambs were pastured to graze the stubble. They grazed for about two weeks before they started feeding on the trees. These lambs were then swapped with a new mob of lambs. Hay was then cropped again. After this harvest the trees were sufficiently high to cope with sheep grazing their lower branches. Virtually no productivity was lost and as the trees started to influence the micro-climate the paddock became more and more productive.

Silvoarable

Silvoarable mixes trees amongst arable or horticultural crops. Alley cropping, sometimes referred to as 'sun systems', is a form of intercropping

Intercropping

Intercropping is the practice of growing two or more crops in proximity. The most common goal of intercropping is to produce a greater yield on a given piece of land by making use of resources that would otherwise not be utilized by a single crop. Careful planning is required, taking into account...

, and can be applied by farmers as a strategy to combat soil erosion, to increase the diversity of farmland, as a means for crop diversification and to derive other integrated benefits. In this practice, crops

Agriculture

Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

are planted in strips in the alleys formed between rows of trees and/or shrubs. The potential benefits of this design

Design

Design as a noun informally refers to a plan or convention for the construction of an object or a system while “to design” refers to making this plan...

include the provision of shade in hot, dry environments (reducing water loss from evaporation

Evaporation

Evaporation is a type of vaporization of a liquid that occurs only on the surface of a liquid. The other type of vaporization is boiling, which, instead, occurs on the entire mass of the liquid....

), retention of soil

Soil

Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

moisture

Moisture

Humidity is the amount of moisture the air can hold before it rains. Moisture refers to the presence of a liquid, especially water, often in trace amounts...

, increase in the structural diversity of the site and wildlife habitat. The woody perennials in these systems can produce fruit

Fruit

In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

, fuelwood, fodder, or trimmings to be made into mulch

Mulch

In agriculture and gardening, is a protective cover placed over the soil to retain moisture, reduce erosion, provide nutrients, and suppress weed growth and seed germination. Mulching in gardens and landscaping mimics the leaf cover that is found on forest floors....

.

Inga alley cropping

Inga alley cropping

Inga alley cropping refers to the plantation of agricultural crops in between the rows of Inga trees. It has been promoted by Mike Hands, 44th in the UK Environment Agency's all-time list of scientists, campaigners, writers, economists and naturalists who, in its view, have done the most to save...

has been proposed as an alternative to the ecological destruction of Slash-and-burn farming. The Inga tree is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

of small tropical, tough-leaved, nitrogen-fixing tree.

Forest farming

Forest farming is an agroforestry practice characterized by the four "I's"- Intentional, Integrated, Intensive and Interactive management of an existing forested ecosystem wherein forest health is of paramount concern. It is neither forestry nor farming in the traditional sense.Forest farming, or...

, also known as 'shade systems', is the sustainable, integrated cultivation of both timber and non-timber forest products in a forest setting. Forest farming is separate and distinct from the opportunistic exploitation / wild harvest of non-timber forest products. Successful forest farming operations produce: mushrooms, maple and birch syrup, native plants used for landscaping and floral greenery (e.g. salal, sword fern, bear grass, cedar boughs and others), medicinal and pharmaceutical products (e.g. ginseng, goldenseal, cascara or yew bark), wild berries and fruit.

Forest gardening

Forest gardening is a food production and agroforestry system based on woodland ecosystems, incorporating fruit and nut trees, shrubs, herbs, vines and perennial vegetables which have yields directly useful to humans...

is a food

Food

Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...

production and land management

Land management

Land management is the process of managing the use and development of land resources. Land resources are used for a variety of purposes which may include organic agriculture, reforestation, water resource management and eco-tourism projects.-See also:*Sustainable land management*Acreage...

system based on woodland

Woodland

Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...

ecosystem

Ecosystem

An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

s, but substituting tree

Tree

A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

s (such as fruit

Fruit

or nut

Nut (fruit)

A nut is a hard-shelled fruit of some plants having an indehiscent seed. While a wide variety of dried seeds and fruits are called nuts in English, only a certain number of them are considered by biologists to be true nuts...

trees), bushes, shrubs, herb

Herb

Except in botanical usage, an herb is "any plant with leaves, seeds, or flowers used for flavoring, food, medicine, or perfume" or "a part of such a plant as used in cooking"...

s and vegetable

Vegetable

The noun vegetable usually means an edible plant or part of a plant other than a sweet fruit or seed. This typically means the leaf, stem, or root of a plant....

s which have yields

Ecological yield

Ecological yield is the harvestable population growth of an ecosystem. It is most commonly measured in forestry;sustainable forestry is defined as that which does not harvest more wood in a year than has grown in that year, within a given patch of forest....

directly useful to humans. Making use of companion planting

Companion planting

Companion planting is the planting of different crops in proximity , on the theory that they assist each other in nutrient uptake, pest control, pollination, and other factors necessary to increasing crop productivity...

, these can be intermixed to grow on multiple levels in the same area, as do the plants in a forest. The Agroforestry Research Trust

Agroforestry Research Trust

The Agroforestry Research Trust is a British non-profit-making charity that researches into temperate agroforestry and all aspects of plant cropping and uses, with a focus on tree, shrub and perennial crops. It produces several publications and a quarterly journal, and sells plants and seeds from...

, managed by Martin Crawford

Martin Crawford

Martin Crawford is Director of the Agroforestry Research Trust, a British charity which conducts research into temperate agroforestry.Martin Crawford has spent over twenty years in organic agriculture and horticulture and is director of The Agroforestry Research Trust, a non-profit-making charity...

, has a 2-acre forest garden in Devon

Devon

Devon is a large county in southwestern England. The county is sometimes referred to as Devonshire, although the term is rarely used inside the county itself as the county has never been officially "shired", it often indicates a traditional or historical context.The county shares borders with...

, United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

Practices

Contour buffers

Contour buffer strip

Buffer strip

A buffer strip is an area of land maintained in permanent vegetation that helps to control air, soil, and water quality, along with other environmental problems, dealing primarily on land that is used in agriculture. Buffer strips trap sediment, and enhance filtration of nutrients and pesticides by...

s are rows of trees or shrubs planted in rows across slopes to reduce soil erosion and give wind protection.

Fertility plantings

Nitrogen-fixing

Nitrogen fixation

Nitrogen fixation is the natural process, either biological or abiotic, by which nitrogen in the atmosphere is converted into ammonia . This process is essential for life because fixed nitrogen is required to biosynthesize the basic building blocks of life, e.g., nucleotides for DNA and RNA and...

trees and shrubs are planted with the main aim of improving nutrient input into the system.

Riparian buffers

Riparian buffer

A riparian buffer is a vegetated area near a stream, usually forested, which helps shade and partially protect a stream from the impact of adjacent land uses...

s are managed forest and shrubs belts in areas bordering lakes, streams, rivers, and wetlands. Integrated riparian management systems are used to enhance and protect aquatic and riparian resources as well as generating income from timber and non-timber forest products. Similar to shelter and timberbelts, integrated riparian management systems can employ a wide variety of tree and shrub species, with specific plantings tailored to suit the specific growing conditions and production opportunities.

Windbreaks

A windbreak

Windbreak

A windbreak or shelterbelt is a plantation usually made up of one or more rows of trees or shrubs planted in such a manner as to provide shelter from the wind and to protect soil from erosion. They are commonly planted around the edges of fields on farms. If designed properly, windbreaks around a...

is a plantation usually made up of one or more rows of trees or shrubs planted in such a manner as to provide shelter from the wind.

Benefits

Agroforestry systems can be advantageous over conventional agricultural and forest production methods through increased productivity, biodiversity

Biodiversity

Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...

, economic benefits, social outcomes and the ecological goods and services provided.

Biodiversity in agroforestry systems is typically higher than in conventional agricultural systems. Agroforestry incorporates at least several plant species into a given land area and creates a more complex habitat that can support a wider variety of birds, insects, and other animals. Agroforestry also has the potential to help reduce climate change since trees take up and store carbon at a faster rate than crops.

Agroforestry tree species of research interest in the tropics, particularly in relation to improving maize yields in sub-Saharan Africa, include the nitrogen fixing species Sesbania sesban, Tephrosia vogelii, Gliricidia sepium and Faidherbia albida. For example, a ten year experiment in Malawi showed that by using fertilizer trees such as Tephrosia vogelii and Gliricidia sepium, maize yields averaged 3.7 tonnes per hectare, compared to 1 tonne per hectare in plots without fertilizer trees or mineral fertilizer. Research with Faidherbia albida in Zambia over several years showed that mature trees can sustain maize yields of 4.1 tonnes per hectare compared to 1.3 tonnes per hectare beyond the canopy of the tree. Unlike other trees, Faidherbia sheds its nitrogen-rich leaves during the rainy crop growing season so it does not compete with the crop for light, nutrients and water. The leaves then regrow during the dry season and provide land cover and shade for crops.

Potential impacts of agroforestry can include:

Reducing poverty through increased production of agroforestry products for home consumption and sale
Contributing to food security by restoring farm soil fertility for food crops and production of fruits, nuts and edible oils
Reducing deforestation and pressure on woodlands by providing fuelwood grown on farms
Increasing diversity of on-farm tree crops and tree cover to buffer farmers against the effects of global climate change
Improving nutrition to lessen the impacts of hunger and chronic illness associated with HIV/AIDS
Augmenting accessibility to medicinal trees, the main source of medication for 80% of Africa's population

Other aims

Agroforestry practices may also be employed to realize a number of other associated environmental aims, such as:

Carbon sequestration
Odour, dust, and noise reduction
Waste water or manure management (e.g. utilizing urban waste water on intensive, short rotation forests for wood fibre production)
Green space and visual aesthetics.
Enhancement or maintenance of wildlife habitat.

External links

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.