Plantation-based single and multistoried cropping systems on hill slopes and paddy in the coastal plains are the two major types of cropping system practiced in these islands. Nicobari and Karen are the two most important farming tribes who depend on coconut- and rice-based systems, respectively. Studies showed that the economic prosperity and sustainability of tribes basically depended on their traditional wisdom to manage land and crop resources and farming practices. Among these, land use, biodiversity, conservation tillage, organic waste recycling, green leaf manuring from live fences, and growing leguminous cover crops in plantations are very important tribal practices. Studies have shown that these indigenous soil and crop management techniques maintain the soil fertility without much degradation of soil and sustain the agricultural productivity and its diversity. But marketable surplus is realized only from coconut and other agricultural products are just sufficient or shared among them. Green manuring and green leaf manuring with local legumes, characterization, and documentation of tubers, roots, fruits, and vegetables, upscaling of locally adapted cultivars, conservation tillage practices of tribes should be promoted to improve the food and nutritional security of the tribes and conserve the island resources.