Subsistence and Commercial Activities. The extended family household was traditionally the basic unit of both Production and consumption. Sago and bananas are the major staples eaten every day. These foods are supplemented by sweet potatoes, taro, yams, breadfruit, okari and galip nuts, greens, sugarcane, pitpit, pineapples, and local fruits. There are two kinds of gardens in the south: extensive banana Gardens (up to 2 hectares) and small, mixed gardens, fenced to keep pigs out. Banana gardens require little tending aside from felling trees and planting suckers around the fallen trunks. Mixed gardens require considerable time for fencing, ground preparation, weeding, and tending. Gardens produce for about two years, after which they should lie fallow for fifteen or more years. Sago is abundant in the south, but it is planted and managed by weeding and cutting selected trees to increase productivity. In the north, sago is less common and monocropping of taro is important. Domesticated pigs run wild in most villages and forage for most of their diet. They are given some food in the evening to keep them from joining the feral herd. Domesticated boars are gelded, and sows are serviced by feral boars. Pork is an important part of the diet; in the dry season it is frequently eaten at pig feasts and other ceremonies, while in the wet season pigs are easily tracked and hunted with shotguns or bows and arrows. Hunting for marsupials and birds is of relatively minor importance, while small fish and crayfish are often caught in large numbers. Sago grubs, frogs, bush eggs, ant larvae, and other foods foraged in the forest are delicacies, but they are of minor importance in the daily diet. Until construction of the Ok Tedi copper mine began, small red chili peppers ( lombok ) were the only cash crop, and they were cultivated on a very small scale. With the coming of the mine, economic opportunities have diversified and expanded into wage employment and vegetable production for cash sale.
Industrial Arts. Crafts include string bags, skirts from rushes, bows, and arrows. Other household utensils are of simple manufacture, using bush materials. Men occasionally make dugout canoes, used only for crossing major rivers. Houses are built high up on tree trunks or on shorter house posts in villages. Floors are of narrow palm slats, roofs are of sago-leaf thatch sewn in panels, and walls are made from the stems of sago fronds.
Trade. Considerable trade was conducted at large pig feasts, which brought together Ningerum, Yonggom, and Muyu from a wide area. This trade consisted of many small transactions involving manufactured goods (string bags and bows), raw materials (rushes for skirts, red ocher), dogs, piglets, cassowary chicks, and magic or other ritual knowledge. Money cowries, nassa shells, and dogs' teeth were the Standard mediums of exchange throughout the region. Men also occasionally went on long-distance trading expeditions as far as Mount Koreom in the west and up into the Star Mountains in the north. There was little product specialization in the lowlands; individuals sold what they had in excess of their needs and bought things that they might need but that they could ordinarily make themselves or get from close relatives. Trade with Star Mountains people was more specialized: Ningerum black-palm bows and shells were traded to Wopkaimin people for tobacco and hand drums, which were obtained from the Tifalmin people farther north.
Division of Labor. Most gardening is a cooperative effort involving a husband and his wife (or wives), often assisted by coresident kin. Women process sago in small groups after a tree has been cut down and opened by men. For tasks that require a great deal of labor—such as house building or clearing and fencing gardens—families often invite twenty to thirty relatives and neighbors to help, reciprocating with an Elaborate meal. Only men hunt with bows and arrows or shotguns, usually by themselves. Both women and men go diving for fish in streams (using fishing arrows and goggles) in small groups. Women do most of the cooking, child tending, and firewood gathering, although men often assist when women are busy with other work. The only cooperative subsistence activity involving large groups (up to 100 men, women, and children) is the occasional use of derris root to poison large numbers of fish when streams are low. Major feasts involve the cooperative effort of two or more local clan segments—occasionally a village—but most construction and food Production for these events is done by a small group of closely related men and women, respectively. Up to 1980, few Ningerum were regularly earning cash wages, and this was almost exclusively a male domain that usually required moving to an urban center or plantation (up to about 1970).
Land Tenure. All land is associated with a named, patrilineal clan segment and, in theory, owned by this group of Individuals. Fallow garden lands are usually considered owned by the male heirs of the last man to have cultivated the property. Usually these rights are held in common by a group of brothers or cousins, but where land is scarce, men may divide their holdings among their sons. Daughters retain rights of usufruct and may cultivate the land with their husbands if they live nearby. Usufruct rights to garden land may be allocated to friends or kin as a way of recruiting nonagnates into the local clan segment. After a generation such land becomes more closely associated with the family of the most recent cultivator than with the original owner. Less commonly, parcels of garden land have been alienated from their original clan segment through purchase by an individual for shell money. Rivers, ritual sites, and hunting lands—as well as the rights to their flora and fauna—are owned in common by the clan segment, whose interests are managed by the clan segment's elders. Land belonging to moribund clan segments can be expropriated by anyone who can make use of the resources and claim usufructuary rights through nonagnatic kin ties, through previous residence, or through former residence on the land of a parent or grandparent.