Archeologists divide Pre-European Hawaiian agriculture into wetland, flood irrigated systems that were restricted to stream valleys and coastal plains of each island and dryland, rainfed systems that covered vast areas of relatively fertile soils on the younger islands.
Each agricultural system had its own pattern of social organization, and development of the dryland systems in particular led to consolidation of social control by the ruling chiefs. (Lincoln) Large scale dryland systems have been found in Kona, Kohala, Kaupo and Kalaupapa (and elsewhere.)
The Kona Field System was not brought to Kona as a fully developed system; but rather, it reflects a developmental adaptation to the area likely associated with the evolving sociopolitical structure and increasing population in Kona.
As population increased to AD 1650, these systems underwent both expansion (to the limits of suitable soil and rainfall conditions) and intensification (in cropping interval, labor input, construction of permanent field borders and animal husbandry.) (Kirch)
The Kona Field System was a nearly continuous series of agricultural fields stretching from the Kaū ahupua‘a (above what is now Kona Airport) in the north to Hoʻokena in the south. The fields cover approximately 34,350-acres across the slopes of Hualālai and Mauna Loa. (Rechtman)
Planting areas were divided by kuaiwi (one translation of the word kuaiwi is ‘backbone;) these are low stone mounds/walls, which may have also served as trails between cultivated areas.
Between the kuaiwi, other traditional Hawaiian planting features are present such as mounds, terraces, modified outcrops and platforms. (Dye)
Early explorers marveled at the size and fertility of Kona’s upland plantations. Archibald Menzies, a surgeon and naturalist who accompanied Vancouver to Kealakekua Bay in 1793, wrote: “As we advanced beyond the bread-fruit plantations, the country became more and more fertile, being in a high state of cultivation.”
“For several miles round us there was not a spot that would admit of it but what was with great labor and industry cleared of loose stones and planted with esculent (kalo, taro) roots or some useful vegetable or other.”
“In clearing the ground, the stones are heaped up in ridges (kuaiwi) between the little fields and planted on each side, either with a row of sugar cane or the sweet root (ti) of these islands … where they afterwards continue to grow in a wild state …”
“… so that even these stony, uncultivated banks are by this means made useful to proprietors, as well as ornamental to the fields they intersect.” (Menzies, 1793)
The Kona system developed into a highly diverse patchwork characterized by a matrix of agricultural practices overlaid onto a spectrum of lava flows of varying ages. (Lincoln)
The kuaiwi, wider than tall, are a series of closely-spaced parallel structures that are parallel to the mauka-makai slope and are intersected by shorter, perpendicular retaining cross-walls.
Kuaiwi extend for several hundred yards to more than a mile in length, so they were probably not the work of individual gardeners, but the result of broader, organized use.
The kuaiwi system is extensive, but is found only in association with fertile soils. Their age, extrapolated from radiocarbon dates of charcoal retrieved from under the structures, indicate fifteenth-to sixteenth-century construction. (Wozniak)
Agricultural fields are thus discernible by the rectangular pattern created by the kuaiwi and cross-walls. The construction of kuaiwi was likely a by-product of land clearing as rocks were removed to create planting areas. (Dye)
The Kona Field System is generally considered a dryland complex, however, water control features, ʻauwai and modified waterholes, have been documented in areas where intermittent streams were present. (Rechtman)
This system is applicable to planting in a dry setting for several reasons: moisture – the kuaiwi are described as being very effective at catching morning dew; mulch – the kuaiwi were constructed using ‘waste’ rocks ranging in size from a pebble to the size of a fist, probably cleared from surrounding fields. (Gon)
We know that there is a very essential process of mulching in which the Hawaiians transferred leaf material from the kuaiwi to the fields. And it is very possible that the kuaiwi played a very essential role in managing the nutrient cycle within the Kona Field System and allowed the Hawaiians to sustain their agriculture over hundreds of years. (Lincoln)
Within the majority of the Kona Field System, the kuaiwi were planted with tall crops such as sugar cane and ti leaf while the cleared fields between the kuaiwi were growing the staple crops such as taro and sweet potato. (Lincoln)
The Kona Field System is without equal in Hawai‘i, and probably in the nation in terms of the extensiveness of a prehistoric modification of the land.
The system is so extensive that it cannot be seen in its entirety except from extremely high altitudes, but the physical remains are sufficiently well preserved and in such generally good condition that they may still be detected on the ground, although it is difficult to realize what is viewed is part of such a massive system.
The vastness and complexity of the system show excellent practical engineering and environmental knowledge of the ancient Hawaiians, as well as the highly evolved social organization which could coordinate the labors of a multitude of people to create and maintain such a system. (Newman)