Quite a few well-intentioned academics, more often than not in the social and ecological sciences, do us no favor by over romanticizing the pre-European contact past of Hawai‘i’s agriculture.
By Bruce Mathews, dean of the College of Agriculture, Forestry and Natural Resource Management, University of Hawai‘i at Hilo.


Hawai‘i rightly takes great pride in its rich agricultural history, the mālama ‘āina (deep care, stewardship, and respect for the land) of the Native Hawaiians, and no doubt much can be learned from the past. This being said, most conservation and resource management discussions in Hawai‘i pertaining to the revitalization of local agriculture tend to be far too insular, and focused on Eden-like interpretation of the past and anecdotal commentary for impactful progress to be made on viable paths forward. Yes, pre-European contact agriculture was self-sufficient, organic by practice, and did not rely on external inputs, however many bio-cultural, technological, and socio-political parameters have changed since that time. And there is strong evidence that pre-European contact agriculture and aquaculture had much greater impacts on Hawai‘i’s environment than previously thought (Kirch, 1982; Anderson et al., 2017). Native Hawaiian upland field systems based largely on intensive ‘uala (sweet potato) cultivation in the highly valued locations of greater natural soil fertility would have eventually run into sustainability challenges induced by gradual soil nutrient depletion (Vitousek et al., 2004; Hartshorn et al., 2006). In this regard it is also worth noting that no till aboriculture/agroforestry based on cultivation of ‘ulu (breadfruit) trees had some distinct environmental and subsistence agriculture advantages and should be further investigated (Rolett, 2008).
Contrary to popular belief regarding the overall importance of kalo (taro) production in the valley lowlands (freshwater marshlands) and loʻi (terraced pondfields irrigated with diverted stream water), there is data suggesting that the dryland food production systems in the uplands provided about half the dietary calories for pre-European contact Hawaiians (Dr. Natalie Kurashima, Integrated Resource Manager, Kamehameha Schools, personal communication, April 9, 2018). It is also interesting to note that by the early 1900s intensive rice cropping with two crops per year to feed Hawai‘i’s growing plantation workforce was leading to soil nutrient depletion (especially potassium) in the valley lowlands which used to sustainably support significant taro production by the Native Hawaiians (Kelley, 1914; Figures 1 vs 2). Without efficient and responsible use of external nutrient inputs the highly productive agriculture of the modern era does not stay productive for long and its land sparing benefits for forests and grasslands are lost.
Indigenous agriculture elsewhere in the world has found adaptive paths to persist and often expand during the present era via eclectic sustainable intensification that is economically viable enough for small and mid-sized farmers to make farming a career option. Sustainable intensification is an agro-ecological approach which does not limit farmers to solely local indigenous practices and crops but rather integrates them with the best modern approaches in an environmentally and socially responsible manner. Hence, it allows for an agriculture that can meet the needs of the present while being as closely aligned to the Mālama ‘Āina stewardship ethic as possible.
Recent cropping systems research by CAFNRM’s Ms. Chantal Vos (Research Associate, College of Agriculture, Forestry and Natural Resource Management, University of Hawai‘i at Hilo ) and Dr. Norman Arancon (Associate Professor of Horticulture, UH Hilo) has shown that many of Hawai‘i’s farmers are struggling with how to optimally use agricultural inputs from both economic and agro-ecological perspectives. We need long-term planning for economically resilient agricultural systems that can work within the prevailing environmental, technological, and socio-political systems. The official motto for the State of Hawai‘i is “Ua Mau ke Ea o ka ‘Āina i ka Pono” (The Life of the Land is Perpetuated in Righteousness), however finding a path forward for significant food crop production has remained elusive in recent decades and this trend was already well apparent by the 1950s (Ripperton et al., 1955).
Quite a few well-intentioned academics, more often than not in the social and ecological sciences, do us no favor by over romanticizing the pre-European contact past of Hawai‘i’s agriculture. These people typically provide little discourse on the adaptive agricultural practices of Native Hawaiians during the past two centuries and do not show much vision in terms of looking beyond Hawai‘i for ideas on how to pave a path towards a productive and resilient future. We also face the challenge that many of the naturally more fertile lands used for food production in past eras are no longer easily accessible due to their now being zoned for conservation (mainly in the valleys and gulches), used for private ranching and subdivisions (fertile uplands in moderate rainfall zones), and in some cases the surface water sources for irrigation were diverted long ago. There are also other bureaucratic constraints like cumbersome policies and the challenges of securing long-term land leases at reasonable cost, etc. This being said we have a kuleana (responsibility) to promote a greater local food self-reliance as it can be argued that importing most of our food results in a form of eco-imperialism. If we want to be a model of sustainability and resilience for other island nation states we must do better. A key component of doing better must be support for good science which allows for reasoned and reasonable explanations of responses to agricultural management practices. And good science is based on well-designed research experiments with appropriate controls, replication, and randomization.
Interestingly, in the quest for improved local food security, some regions of the tropics/subtropics in South and SE Asia, and Sub-Saharan Africa are now actively exploring expansion of agriculture along the hydromorphic fringes of riverbanks, valley bottoms, and the bases of valley walls through integrated approaches with reduced risk for agricultural pollution. These are the very types of landforms where much of indigenous agriculture originated, including that of the Native Hawaiians and many Native Americans. Factors driving a resurgence of interest in farming these bottomlands include a reduced need for expensive fertilizer inputs for the soils derived from alluvium and colluvium, reduced risks associated with drought and climate change, the ability to more easily integrate aquaculture, and a less frequent need for fallowing. A holistic knowledge-intensive agriculture is the Mālama ‘Āina way forward.
For more information the reader is referred to Wakatsuki and Masunaga (2005); Gurung et al. (2012); Obalum et al. (2012); Rodenburg (2013); and Chong (2017).
Partial list of References
Anderson, B., L. Zhang, H. Wang, T. Lu, F.D. Horgen, J. Culliney, and J. Fang. 2017. Sedimentary carbon and nitrogen dynamics reveal impact of human land use change on Kawainui Marsh. O‘ahu, Hawaiʻi. Pac. Sci. 71:17-27.
Chong. E.S. 2017. Riverbank farming: An unutilized resource in the quest for food security. Penang Inst., Penang, and The Malaysian Insight, Kuala Lumpur, Malaysia.
Gurung, G.B., P. Koirala, D.P. Pande, D.B. Basnet, and O. Kafle. 2012. Promoting rural livelihoods through riverbed vegetable farming in the Tarai Region of Nepal. J. Int. Dev. Coop. 18:113-121.
Hartshorn, A.S., O.A. Chadwick, P.M. Vitousek, and P.V. Kirch. 2006. Prehistoric agricultural depletion of soil nutrients in Hawai‘i. Proc. Nat. Acad. Sci. 103:11092- 11097.
Kelley, W.P. 1914. Rice soils of Hawaii: Their fertilization and management. Hawaii Agric. Exp. Stn Bull. 31. USDA, Washington, DC.
Kirch, P.V. 1982. Impact of prehistoric Polynesians on the Hawaiian ecosystem. Pac. Sci. 36:1-14.
Obalum, S.E., M.M. Buri, J.C. Nwite, Hermansah, Y. Watanabe, C.A. Igwe, and T. Wakatsuki. 2012. Soil degradation-induced decline in productivity of Sub-Saharan African soils: The prospects of looking downwards to the lowlands with the Sawah ecotechnology. Appl. Environ. Soil Sci. 2012: Article 673926.
Ripperton, J.C., M. Takahashi, and E.Y. Hosaka. 1955. Field crops and pastures. p. 165-203. In M.G. Cline (ed.) Soil survey of the Territory of Hawaii: Islands of Hawaii, Kauai, Maui, Molokai, and Oahu. USDA Soil Conservation Service, Washington, DC.
Rodenburg, J. 2013. Inland valleys: Africa’s future food baskets. p. 276-293. In M.C.S. Wopereis et al. (ed.) Realizing Africa’s rice promise. CAB International, Wallingford, Oxfordshire, UK.
Rolett, B.V. 2008. Avoiding collapse: Pre-European sustainability on Pacific Islands. Quarternary Intl. 184:4-10.
Vitousek P.M., T.N. Ladefoged, P.V. Kirch, A.S. Hartshorn, M.W. Graves, S.C. Hotchkiss, S. Tuljapurkar, and O.A. Chadwick. 2004. Soils, agriculture, and society in precontact Hawai’i. Science 304:1665–1669.
Wakatsuki, T., and T. Masunaga. 2005. Ecological engineering for sustainable food production and the restoration of degraded water- sheds in tropics of low pH soils: Focus on West Africa. Soil Sci. Plant Nutr. 51:629-636.
–May-June issue of the CAFNRM Newsletter.