REHABILITATION OF SHIFTING CULTIVATION AREAS THROUGH AGROFORESTRY: A CASE STUDY IN EASTERN HIMALAYA, INDIA

Abstract

Bhatt BP, LB, KK, YP & KM. 2010. Rehabilitation of shifting cultivation areas through agroforestry: a case study in eastern Himalaya, India. A study was carried out for 10 years (1992–2002) in Meghalaya, India, involving seven multipurpose tree species, viz. Acacia auriculiformis, Alnus nepalensis, Bauhinia purpurea, Exbucklandia populnea, Ficus hookeri, Michelia champaca and M. oblonga planted on shifting cultivation degraded land. The tree species were intercropped with broom grass (Thysanolaena maxima). The study revealed that M. champaca had the highest survival (80%) and F. hookeri, the lowest (40%). Current annual increment (CAI) was highest in
A auriculiformis (2.3 m and 2.6 cm respectively for height and diameter growth), while mean annual increment (MAI) for height and diameter growth was highest in E. populnea (1.4 m) and A nepalensis
(1.9 cm) respectively. Exbucklandia populnea exhibited the greatest height (14.8 m). Diameter growth was, however, highest (63.2 cm) in A. nepalensis after 10 years. Maximum basal cover, leaf area and standing biomass were recorded in A. auriculiformis including its timber (0.3 m³/tree) and standing volume (220.3 m³ ha^-1). Lowest standing volume was, however, recorded in B. purpurea (15.4 m³ ha^-1). Variations were observed for growth performance and biomass yield of the tree species. Thysanolaena maxima exhibited total productivity of 89.3 q ha^-1 in control plots (without trees) with fodder, spike and firewood yield of 36.3, 16.5 and 36.6 q ha^-1 respectively. However, its productivity reduced 40% when intercropped with A. nepalensis. Reduction in the yield of broom (5.2%) was lowest when intercropped with B. purpurea. The results revealed that A. auriculiformis, A. nepalensis, E. populnea and Michelia spp. (tree crops) and T. maxima (understorey crop) could be recommended for restoration of shifting cultivation areas in eastern Himalaya, India.