Silviculture & Agroforestry

The Diagnosis and Design (D&D) methodology developed by ICRAF (World Agroforestry Centre / Raintree, 1987) follows a logical sequential four-stage process:

• Pre-diagnostic Stage (A): Environmental description, definition of the land-use system, and preliminary assessment.
• Diagnostic Stage (B): Identification of land-use problems, system constraints, causal factors, and farmer needs.
• Design and Evaluation Stage (C): Development of agroforestry technologies and candidate interventions to solve the identified constraints, followed by ex-ante evaluation.
• Planning and Implementation Stage (D): Designing research and development activities, project planning, and field execution.

In P.K.R. Nair's globally recognized classification of agroforestry systems, the socio-economic classification groups systems into three levels of economic scale and production objective:

• Subsistence systems: Land use directed towards meeting the basic survival needs (food, fuel, fodder) of the farm family.
• Intermediate systems: Land use between subsistence and commercial, where cash crops are sold and surplus is marketed.
• Commercial systems: Land use oriented toward scale production where sale of commercial produce is the primary aim.
  'Interpolated' is a mathematical or spatial term and is NOT an economic category of agroforestry.

Homegardens (such as Kandyan gardens in Sri Lanka or homesteads in Kerala) are complex multistoried agroforestry systems around dwellings:
When only multipurpose trees, shrubs, fruit trees, and vegetables/spices are cultivated, they function as an Agri-silvicultural system.
However, when domestic livestock (cows, goats, poultry, pigs, or bees) are also integrated within the homestead to feed on fodder and crop residues, they function as an Agri-silvi-pastural system.