Agro-forestry is a kind of agricultural practices where by fast growing trees are grown along with a crop. The trees help to maintain nitrogen fixation in soil and also humidity to soil. Moreover trees also prevent soil erosion by wind and provide fodder and fruits. The concept of agro- forestry aims at maximizing the agricultural production by minimizing damage to the environment. In agro-forestry a proper combination of crop-tree is necessary Such as: – pearl millet – subabul large cardemon -vtis Sesamunm – Kirar.
The concept of agro-forestry has been basically developed due to environmental problems because there is serious concern over degradation of environment. The serious adverse ecological manifestation such as increase of carbon dioxide, in the atmosphere, global warming soil losses, repeated droughts, floods and pollution etc. are the result of dwindling forest resources. An agro-forestry system will help to increase the tree cover. It also makes available to people the required quantity of timber, fruit, fuel -wood, fodder etc. for which they traditionally depend on forests. Thus this system helps in reducing the pressure on forests and helps in conservation and development.
Different areas are also under the threat of pollution such as air, water and noise pollution and trees can guard, from these pollutants. The best safeguard against landslides can be through agro-forestry but this requires careful selection of tree species, grasses etc. The agro-forestry also maintains soil fertility through re-cycling of nutrients and prevents soil erosion and loss nutrients through leaching and run off. Many leguminous tree species fix nitrogen from the atmosphere and return much more in leaf fall than they take from the soil.
Leaves of the trees could also be used as green manure and help the farmer in increasing soil fertility. Agro-forestry system is therefore, helpful in maintaining land productivity at optimum levels over a long period of time and this system also constitute sustainable land management.
There are various forms of agro-forestry such as:
(i) Agri-silviculture system:
In this system, trees species are grown and managed in the farmland along with agricultural crops.
(ii) Silvipastoral system:
In this system of agro- forestry pastures crops are growth along with trees species.
(iii) Agri-silvipastoral system:
Under this system, the same unit of land is managed to get agricultural and forest crop where farmers can also rear animals.
(iv) Agri-horticulture system:
Under this system agricultural crops are grown along with fruit trees.
(v) Silvi-horticultural system:
In this system, trees species are managed to get timber, fuel wood etc. and horticulture crops are grown in the interspace.
(vi) Silvi-hortipastoral system:
A combination of tree species, horticultural crops and grasses are practiced in this system. The three combinations are based on the principle that each of its components draws nutrients from different layers of soil.
(vii) Silvi – agri Sericulture system:
This is a very complex system of agro-forestry. In this system, crops, vegetables are grown with tree species i.e. Silk host plants. The warm’s larval excreta are good manure for the crops and vegetables.
(viii) Multi-storeyed agro forestry system:
This system is managed by the combination between cultural practices and the natural processes of vegetation, production and reproduction. It represents a profitable production system and constitutes an efficient buffer between villages and forests. This is common in coastal parts of Southern India where coconut grown with black pepper and tapioca.
(ix) Aqua-agri-hortipastoral system:
In this system, fruit tees are planted on the terraced land around the water tanks, ponds and crops are grown in the intersperse. The fallen leaves of trees enrich the pond nutrients for fish.