Agroforestry is a collective name for land-use systems  involving trees combined with crops and/or animals on the same unit of land. It  combines  
          1) Production of multiple outputs with protection of the resource  base; 
          2) Places emphasis on the use of multiple indigenous trees  and shrubs; 
          3) Particularly suitable for low-input conditions and  fragile environments; 
          4) It involves the interplay of socio-cultural values more  than in most other land-use systems; and  
          5) It is structurally and functionally more complex than  monoculture. 
        
         
        
        1) Agroforestry is any sustainable land-use system that  maintains or increases total yields by combining food crops (annuals) with tree  crops (perennials) and/or livestock on the same unit of land, either  alternately or at the same time, using management practices that suit the  social and cultural characteristics of the local people and the economic and  ecological conditions of the area.  
        2) Agroforestry is a collective  name for a land-use system and technology whereby woody perennials are  deliberately used on the same land management unit as agricultural crops and/or  animals in some form of spatial arrangement or temporal sequence. In an  agroforestry system there are both ecological and economical interactions  between the various components. 
         
        
          
            
                DIFFERENCE BETWEEN SOCIAL FORESTRY AND AGROFORESTRY 
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        Social forestry is defined as “Forestry outside the conventional forests which primarily aim at providing continuous flow of goods and services for the benefit of people. This definition implies that the production of forest goods for the needs of the local people is Social forestry. Thus, social forestry aims at growing forests of the choice of the local population.  
          Shah (1985) stated that Conceptually Social forestry deals with poor people to produce goods such as fuel, fodder etc. to meet the needs of the local community particularly underprivileged section.  
         
        
          
            
                DIFFERENT TERMINOLOGIES FOR DESCRIBING TREE CULTIVATION IN  NON-FOREST AREAS 
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          1) Farm Forestry: Farm  forestry is the name given to programmes which promote commercial tree growing  by farmers on their own land. Farm  forestry was defined by NCA (1976) as the practice of forestry in all its  aspects in and the around the farms or village lands integrated with other farm  operations.  
   
  2) Extension  Forestry:  It is the practice of forestry in areas devoid  of tree growth and other vegetation situated in places away from the  conventional forest areas with the object of increasing the area under tree growth.  
          It includes the following. 
  a)  Mixed forestry   
    It is the practice of forestry  for raising fodder grass with scattered fodder trees, fruit trees and fuel wood  trees on suitable wastelands, panchayat lands and village commons 
  b)  Shelterbelts 
    Shelterbelt is defined as a belt  of trees and or shrubs maintained for the purpose of shelter from wind, sun,  snow drift, etc.  
  c)  Linear Strip plantations 
    These are the plantations of  fast growing species on linear strips of land. 
        
          
              
                Linear strip plantations  | 
           
         
        3) Rehabilitation of Degraded forests: The  degraded area under forests needs immediate attention for ecological  restoration and for meeting the socio economic needs of the communities living  in and around such areas. 
               
              4) Recreation Forestry: It is the practice of  forestry with the object of raising flowering trees and shrubs mainly to serve  as recreation forests for the urban and rural population. This type of forestry  is also known as Aesthetic forestry which  is defined as the practice of forestry with the object of developing or  maintaining a forest of high scenic value. 
        
         
        
          
            
                TYPES OF AGROFORESTRY SYSTEMS 
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        1. STRUCTURAL BASIS : 
          A. NATURE OF COMPONENTS 
        I) AGRISILVICULTURAL SYSTEMS 
        
        In this system, agricultural crops are intercropped  with tree crops in the interspace between the trees. Under this system  agricultural crops can be grown upto two years under protective irrigated  condition and under rainfed farming upto four years. The crops can be grown  profitably upto the above said period beyond which it is uneconomical to grow  grain crops. However fodder crops, shade loving crops and shallow rooted crops  can be grown economically. Wider spacing is adopted without sacrificing tree  population for easy cultural operation and to get more sunlight to the  intercrop. Performance of the tree crops is better in this system when compared  to monoculture.  
         
        
          
            II) SILVOPASTORAL SYSTEMS  | 
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        The production of woody plants  combined with pasture is referred to Silvipasture system. The trees and shrubs  may be used primarily to 
          produce fodder for livestock or they may be grown for  timber, fuelwood, fruit or to improve the soil.  
            This system is classified in to three  categories 
        
          
            a) Protein bank 
                
                b) Livefence of fodder trees and hedges 
                  c) Trees and shrubs   on pasture 
                   
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        a) Protein bank: 
          In this Silvipastoral  system, various multipurpose trees (protein rich trees) are planted in or  around farmlands and range lands for cut and carry fodder production to meet  the feed requirement of livestock during the fodder deficit period in winter. 
  Example: Acacia nilotica, Albizia lebbeck, Azadirachta indica, Leucaena  leucocephala, Gliricidia sepium, Sesbania grandiflora 
        b) Livefence of fodder trees and hedges: 
          In this system, various  fodder trees and hedges are planted as live fence to protect the property from  stray animals or other biotic influences. 
  Example: Gliricidia sepium, Sesbania grandiflora, Erythrina sp, Acacia sp. 
        c) Trees and shrubs on pasture: 
          In this system, various tree and shrub  species are scattered irregularly or arranged according to some systemic  pattern to supplement forage production. 
  Example: Acacia nilotica, Acacia leucophloea  ,Tamarindus indica, Azadirachta indica. 
        
         
        
          
            
                III) AGROSILVOPASTORAL SYSTEMS 
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        The production  of woody perennials combined with annuals and pastures is referred  Agrisilvopastural system. 
          This system is  grouped into two categories. 
         
              
        
          
            a) Home gardens 
              b) Woody hedgerows for browse, mulch, green manure and soil  conservation  | 
           
         
        a) Home gardens 
             
          This system is found extensively in  high rainfall areas in tropical South and    South east Asia. This practice finds  expression in the states of Kerala and Tamil Nadu with humid tropical climates  where coconut is the main crop. Many species of trees, bushes , vegetables and  other herbaceous plants are grown in dense and in random or spatial and  temporal arrangements. Most home gardens also support a variety of animals.  Fodder grass and legumes are also grown to meet the fodder requirement of  cattle. In India,  every homestead has around 0.20 to 0.50 ha land for personal production. 
   
          Home gardens represent land use  systems involving deliberate management of multipurpose trees and shrubs in  intimate association with annual and perennial agricultural crops  and livestock within the compounds of  individual houses. The whole tree- crop- animal units are being intensively  managed by family labour. Home gardens can also be called as Multitier system or Multitier cropping. 
   
          Home gardens are highly productive,  sustainable and very practicable. Food production is primary function of most  home gardens. 
        Structure of Home Gardens: 
               
        Home gardens are characterized by  high species diversity and usually 3-4 vertical canopy strata. The layered  configuration and compatible species admixture are the most conspicuous  characteristics of all home gardens. Generally all home gardens consist of an  herbaceous layer near the ground, a tree layer at the upper levels and an  intermediate layer. The lower layer can be partitioned into two, the  lowermost being at less than 1.0m in height, dominated by different  vegetables and the second layer of 1.0 -3.0/m height comprising food crops  such as banana, papaya and so on. The upper tree layer can also be divided into  two, consisting of emergent , full grown timber and fruit trees  occupying the upper most layer of 25m height and medium size trees of  10-20m occupying the next lower layer. The intermediate layer of 5-10m height  is dominated by various fruit trees. 
        Choice of species: 
          a) Woody species: Anacardium  occidentale,Artocarpus heterophyllus, Citrus spp, Psiduim guajava, Mangifera  indica, Azadirachta indica, Cocus nucifera, 
          b) Herbaceous species: Bhendi,  Onion, cabbage, Pumpkin, Sweet potato, Banana, Beans, etc. 
        b) Woody Hedgerows: 
              In this system various woody hedges,  especially fast growing and coppicing fodder shrubs and trees are planted for  the purpose of browse, mulch, green manure, soil conservation etc. The  following species viz., Erythrina sp,  Leucaena luecocephala, Sesbania grandiflora   are generally used. 
        
        a) Apiculture  with trees: In this system various honey (nector) producing trees  frequently visited by honeybees are planted on the boundary of the agricultural  fields 
        
        b) Aquaforestry: In this system various trees and shrubs preferred by fish are planted on  the boundary and around fish ponds. Tree leaves are used as feed for fish. The  main role of this system is fish production and bund stabilization around fish  ponds 
        c) Mixed wood  lots: In this system, special location specific MultiPurpose Trees   ( MPTs) are grown mixed or separately  planted for various purposes such as wood, fodder, soil conservation , soil  reclamation etc. 
         
        
          
            B. ARRANGEMENT OF COMPONENTS  | 
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            I) Spatial  arrangement  
              II) Temporal  arrangement  | 
           
         
        ) Spatial Arrangement: Spatial  arrangement of plants in an agroforestry   mixture may result in dense mixed stands ( as in home gardens) or in  sparse  mixed stands ( as in most systems  of trees in pastures).  
               
              b) Temporal Arrangement: Temporal  arrangements of plants in Agroforestry may also take various forms. An extreme  example is the conventional shifting cultivation cycles involving 2-4 years of  cropping and more than 15 years of fallow cycle, when a selected woody species  or mixtures of species may be planted. Similarly, some silvipastoral systems  may involve grass leys in rotation with some species of grass remaining on the  land for several years. These temporal arrangement of components in  agroforestry are termed coincident, concomitant, overlapping, separate and  interpolated. 
        
         
        
          
           
            All agroforestry  systems have two functions. 
            A) Productive functions,  
            B) Protective functions  
        A) Productive functions 
        
        
            
            
          
            
              The Productive functions are: 
                I) Food 
                II) Fodder  
                III) Fuel wood 
                IV) Cloths  
                V) Shelter  
                VI) NTFPs  | 
             
           
         
          
          
          
        B) Protective functions 
        
          
        
            
            
          
            
              The Protective functions are: 
                i) Wind breaks 
                II) Shelterbelts 
                III) Soil conservation 
                IV) Soil improvement  | 
             
           
            
            
            
         
         
        
          
            3. SOCIO-ECONOMIC  CLASSIFICATION  | 
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Based  on socioeconomic criteria as scale of production and level of technology input  and management, agroforestry systems have been grouped in to three categories.
        
          A) Commercial    Agroforestry systems 
            B) Intermediate Agroforestry systems 
            C) Subsistence   Agroforestry systems 
         
        A) Commercial AF systems: 
          The term commercial is used whenever  the scale of the production of the output is the  major aim of the system. 
    Examples: 
    a) Commercial production of plantation crops such as rubber,  oilpalm, and coconut  with permanent underplanting of   food  crops, pastures 
  b) Commercial  production shade tolerating plantation crops such as coffee, tea and cocoa under overstorey of shade  trees 
        B) Intermediate AF systems:  
          Intermediate systems are  those between commercial and subsistence scale of production and management. 
   Examples:  
  Production of  perennial cash crops and subsistence food crops undertaken on farms wherein the cash crops fulfill the cash  needs and the food crops meet the family‘s  food needs. 
   
  C) Subsistence AF systems: 
          Subsistence  AF systems are those wherein the use of land is directed towards satisfying  basic needs and is managed mostly by the owner and his family. 
         
        
         
        
          
            4.ECOLOGICAL CLASSIFICATION  | 
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        A) Humid / sub humid 
          B) Semiarid / arid 
          C) Highlands  
        A) Agroforestry  systems in Humid / Subhumid lowlandsExamples: 
        Homegardens, Trees on rangelands and pastures, improved fallow in shifting  cultivation and Multipurpose woodlots. 
        B) Agroforestry  systems in Semiarid and arid lands Examples:  
        Various forms of silvopastoral systems, wind breaks and  shelterbelts. 
        C) Agroforestry  systems in Tropical High lands Examples:   
          Production systems involving plantation crops  such as coffee, tea, use of woody perennials  in soil conservation and improved fallow. 
         
        
          
            BENEFITS OF AGROFORESTRY SYSTEM   | 
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         A)  Environmental benefits 
          i)    Reduction  of pressure on natural forests. 
          ii     More  efficient recycling of nutrients by deep rooted trees on the site 
          iii)  Better  protection of ecological systems 
          iv)  Reduction  of surface run-off, nutrient leaching and soil erosion through impeding effect  of tree roots and stems on these processes 
          v)   Improvement of microclimate, such as  lowering of soil surface temperature and reduction of evaporation of soil  moisture through a combination of mulching and shading 
          vi)  Increment in soil nutrients through  addition and decomposition of litterfall. 
          vii) Improvement  of soil structure through the constant addition of organic matter from  decomposed litter. 
        B) Economic benefits
        i)          Increment  in an outputs of food, fuel wood , fodder, fertiliser and timber; 
          ii)         Reduction  in incidence of total crop failure, which is common to single cropping or  monoculture systems 
          iii)        Increase  in levels of farm income due to improved and sustained productivity 
        C) Social benefits     
        i)          Improvement in rural living standards  from sustained employment and higher income 
          ii)         Improvement in nutrition and health due  to increased quality and diversity of food outputs 
          iii)       Stabilization and improvement of  communities through elimination of the need to shift sites of farm activities. 
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