AGROFORESTRY
INTRODUCTION
Agroforestry is a collective name for land-use systems involving trees combined with crops and animals on the same unit of land. It combines
DEFINITION
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.
DIFFERENCE BETWEEN SOCIAL FORESTRY AND AGROFORESTRY
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.
TYPES OF AGROFORESTRY SYSTEMS
1.STRUCTURALBASIS 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
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, fuel wood, fruit or to improve the soil.
This system is classified in to three categories a) Protein bank
b) Live fence of fodder trees and hedges and c) Trees and shrubs on pasture
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) Live fence 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
The production of woody perennials combined with annuals and pastures is referred Agrisilvopastural.system.This system is grouped into two categories.
a)Home gardensb) Woody hedgerows for browse, mulch, green manure and soil conservation
a) Home gardensThis 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.
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.
B. ARRANGEMENT OF COMPONENT
I ) Spatial arrangement II) Temporal arrangement
a) 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.
2. FUNCTIONAL BASIS
All agroforestry systems have two functions.A) Productive functions, B) Protective functions
A) Productive functions B) Protective functions
The Productive functions are: The Protective functions are:I) Food i) Wind breaks II) Fodder II) ShelterbeltsIII) Fuel wood III) Soil conservationIV) Cloths IV) Soil improvementV) Shelter VI) NTFPs
3. SOCIO-ECONOMIC CLASSIFICATION
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 systemsB) Intermediate Agroforestry systemsC) 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, pasturesb) 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.
BENEFITS OF AGROFORESTRY SYSTEM
A) Environmental benefitsi) Reduction of pressure on natural forests.ii) More efficient recycling of nutrients by deep rooted trees on the siteiii) Better protection of ecological systemsiv) Reduction of surface run-off, nutrient leaching and soil erosion through impeding effect of tree roots and stems on these processesv) Improvement of microclimate, such as lowering of soil surface temperature and reduction of evaporation of soil moisture through a combination of mulching and shadingvi) 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 systemsiii) 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 incomeii) Improvement in nutrition and health due to increased quality and diversity of food outputsiii) Stabilization and improvement of communities through elimination of the need to shift sites of farm activities.
