Soil nutrients and pre‐European contact agriculture in the leeward Kohala field system, Island of Hawai‘i

Abstract

ABSTRACTStudies in the leeward Kohala field system on Hawai‘i Island have considered the processes and timing of agricultural development associated with sociopolitical transformations and the production of agricultural surpluses. Using extensive soil sampling, we explore the use of relatively mobile and immobile soil parameters within the agricultural landscape to interpret the development and maintenance of the system over time. Results show that in the context of the leeward Kohala field system, the immobile element niobium can be used to interpret the location of ancient ground surfaces and that phosphorus is stable enough to be used to understand anthropogenic influences. In contrast, total and exchangeable calcium are too mobile to indicate purely anthropogenic processes. Data suggest that there was more intensive depletion of soil phosphorus on agricultural alignments than in field areas between the alignments, potentially explained by traditional cropping methods associated with the system. Spatial analyses within the field system identifies an area with high naturally occurring soil nutrient levels.