Intensive Cultivation Dani agricultural practices provide a example of an intensive system of crop production based on irrigation. The Dani people live in a tropical highland environment on the island of New Guinea, which is generally associated with extensive cultivation. In fact this region has provided classical case studies of swidden farming, and the Dani present a example of intensive irrigation technologies that is unique in the wider Melanesian region.
Pigs are of course the main protien source.
The local irrigation system is based on digging ditches to tap the many small streams that run through the valley bottom and mounding up the land between these channels to form raised rectangular fields. The ditches serve both to water the crops in the dry season and drain them during the rains. Heider does not discuss how the flow is actually controlled to adjust for fluctuations or ensure that all the users receive adequate amounts, but presumably the Dani have established some system of water regulation. The irrigation ditches are in themselves a twofold resource for the farming system. They supply not only water but also fertilizer in the form of washed off top soil that becomes mixed with rotting plant wastes deposited after the harvest.