This week I am inspired to write about the origin of domesticated plants in New Guinea after learning of the significant discovery by archaeologists Prof. Glen Summerhays of the University of Otago and UPNG’s Dr. Mathew Leavesley, at Kosipe archaeological site. Congratulations to both of them as well as to Herman Mandui from the National Museum and Art Gallery for a spectacular job. The UPNG students who worked with them deserve praise for making the discovery of the century.
The discovery is significant enough to warrant an extended story about the activities of our ancestors. It is our ancestors’ story as much as it is ours. There is more we need to discover about ourselves. I have always been a keen enthusiast for the peopling of the Island of New Guinea and the domestication of plants. The island of New Guinea is truly a world of its own basked in the mysteries of this world.
Domesticated plants in New Guinea were introduced from the Southeast Asian train. The traditional food crops introduced from Southeast Asia include starch staples such as Colocasia esculenta (Taro), Dioscorea alata (Long Yam; Greater Yam), Dioscorea esculenta (Common or Round Yam; Lesser Yam); from Tropical South America the introduction of Ipomoea batatas (Sweet Potato) from Southeast Asia the introduction of Musa (Eumusa Section) or the banana. Two of the secondary crops introduced from Southeast Asia are the Psophocarpus tetragonolobus (Wind Bean) and the Lablab niger (Hyacinth Bean).
The entry of these crops, with the exception of sweet potato, to New Guinea together with domesticated animals is thought to have gone back to more than 50,000 years. The entry of the sweet potato is so recent and is dated to the arrival of European colonialism in island Southeast Asia, which began in the early 16th century. The introduced plants were domesticated together with plants indigenous to New Guinea.
According to the archaeologist, J. Golson of Kuk fame “agriculture could have begun independently of Southeast Asia” since the “starchy foods….could have been the staples, with edible grasses and leafy green vegetables providing minerals and fats; Pandanus trees supplying fruits or nuts rich in proteins and fats, together with other unlisted nut and seed bearing trees; and sugar cane an fruits as intermittent energy sources.”
The following food plants are indigenous: Starchy food such as Musa (Australimusa Section) or banana, Dioscorea bulbifera (yam), Dioscorea hispida (yam), Dioscorea nummularia (yam), Dioscorea pentaphylla (yam), Metroxylon spp. (sago); edible grasses such as Setaria palmifolia (for shoots) or Fox-tail or Bristle Grass; Pitpit (Tokpisin) and Saccharum edule (for inflorescences) or Pitpit (Tokpisn); Leafy green vegetable (Kumu in Tokpisin) such as Abelmoschus (formerly Hibiscus) manihot or Aipika (Tokpisin), Amaranthus spp. (native spinach; Amaranths Coleus); Coleus sp, Commelina spp. Oenanthe javanica; Rorippa sp (Native Cress), Rungia klossii, Solanum nigrum; Nuts and fruits such as pandanus spp. (Screw Pine; Pandanus) and Rubus rosifolius (Native Raspberry). The indigenous plants were either domesticated or were naturally growing or transplanted in gardens from the bush.
The pattern of cultivation of these plants suggests that people in New Guinea were for the most part aware of the abundance of starchy food crops and plants that are easily cultivated to produce sufficient supply of protein and vitamins for their survival. This could explain their early horticultural activities around cultivated agriculture, and reliance of the forest, swamps, and grassland to sustain their livelihood. “It is a reasonable inference from archaeological record,” Golson agues, “that the human settlement of New Guinea began before agriculture of any kind was established in the island.”
“The early communities” Golson continues, “must have lived off the wild resources of the land” as indicated by in various ethnographic studies. It is important to keep in mind that the crop variations in time and space, varies greatly in New Guinea. Some of these plants were cultivated in different time periods and at different levels of topography and climates. The example of banana is that it can only grow at elevation of 2200 m where as sweet potato can grow very well at higher altitudes.
It is generally held that the history of New Guinea agriculture at large has been one of adjustments in response to a variety of circumstances, including the introduction of new plants. The New Guinea agricultural system, for the most part includes shifting cultivation to enable its tuberous crops to be cultivated.
According to Golson the persistence of shifting cultivation throughout the tropical world, under different climatic, physiographic, soil and vegetation regimes, serving a bewildering variety of cultivated plants. marks it out as a highly successful adaptation of forested conditions.
In agreement is the view that “partial or complete clearance of vegetation, burning the debris, the temporary cultivation of an assemblage of crops in the cleared area, and the clearing of further forest for new gardens while the old plot is abandoned to fallow under regenerating forest” helps regenerate the ecosystem (Clarke 1977; 1978; Golding n.d.: 44).
“The complex inter-planting of a diversity of crops,” Golson argues “reproduces the ecosystem diversity of the rainforest from which the garden is cleared, and to which it will shortly return.” The advantages of this polycultivation system is that “it supplies a variety of foods to diversify the diet, which comes to maturity at different stages during the life of the garden; it provides a continuous ground-cover that cuts down the need for weeding and checks erosion; and it reduces the threat from crop diseases and pests to which monocultural plantings are prone.”
Golson observed further that this forest fallowed cultivation is self-maintaining, has no need of external energy or nutrient sources, and produces a greater yield for every unit of human energy than other agricultural systems.
Tropical rainforest with its species diversity and high biological productivity, can flourish even on the poorest soil, because a large part of the nutrients is contained in the biomass itself and their recycling is rapid and efficient.
Agriculture in New Guinea began in the lowlands before entering the highlands.