Structural analysis and mapping of agroforestry systems under irrigated ecosystem in north-eastern part of Karnataka, India

Agroforestry, of late, is drawing more attention in the world as vagaries of climate change take the spotlight. However, still traditional systems prevail on farms and the type and composition of the tree species, their distribution and extent vary with the biophysical and socioeconomic factors. Therefore, structural analysis and mapping of agroforestry systems was carried out under irrigated ecosystem in north-eastern part of Karnataka, India covering six districts. Six prominent agroforestry systems were in vogue predominated by bund planting (43.06%) followed by boundary planting (19.44%), silvihorti systems (12.50%), scattered planting (4.17%) and silvipasture system (2.78%), while block plantation system was part of integrated farming systems on the farm. In all, 52 tree species with a mean species density of 9.04 ha−1 and mean number of trees 104.24 ha−1 were observed in this ecologically endangered region. Among different holding sizes, higher number of trees occurred with large farmer (122.48 ha−1) followed by medium farmer (100.45 ha−1) and the lowest with small farmer (91.82 ha−1). Among the districts, significantly higher mean number of species was observed in Kalaburagi district (11.25 ha−1) followed by Bidar (9.08) and lower mean number of species was recorded in Koppal (7.75 ha−1) followed by Ballari (8.58). Among the tree species Tectona grandis, Azadirachta indica, and Cocos nucifera were the preferred perennials. Farmers preferred the planting of trees on bund and boundary of the farm. The composition, diversity and density of trees in the agroforestry systems are influenced by physical and socio-economic factors. The main physical factor is altitude which influenced the species richness. However, the tree density is influenced by farm holding size and kind of agroforestry system and farmers preferred species having higher economic value and multiple utility.