Agro forestry

Agroforestry combines trees, crops and livestock deliberately on the same plot of land, with the explicit aim of managing the beneficial interactions between them rather than treating cropping and tree-growing as separate land uses. A typical example is intercropping two or more field crops between rows of trees or shrubs, which raises overall yield per unit area and lowers operating costs compared with monoculture farming or monoculture forestry alone. Commercially, Tamil Nadu grows species such as Casuarina, Eucalyptus, Malai Vembu, Teak and Kadambu under agroforestry — all among the 20 species officially identified as commercial timber and important to wood-based industry. Beyond the direct yield benefit, agroforestry stabilises soil salinity and water table, reduces landslide risk and surface run-off, improves nutrient cycling and organic matter content, and the tree canopy moderates the local microclimate by balancing O2–CO2 exchange, temperature and humidity for the crops growing beneath it — making it especially valuable on dry land with minimal rainfall, where it functions as an alternate land-use system. A related practice, the silvopasture system, produces woody plants together with pasture: multipurpose trees such as Acacia nilotica, Albizzia lebbek, Azadirachta indica, Gliricidia sepium and Sesbania gr …