Adaptation of a Natural Farming System to Vegetable Farm Production in Hawaii.

Final Report for SW99-022

Project Type: Research and Education
Funds awarded in 1999: $85,134.00
Projected End Date: 12/31/2003
Matching Non-Federal Funds: $182,505.00
Region: Western
State: Hawaii
Principal Investigator:
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Project Information


This project was intended to demonstrate a natural, sustainable farming system in a subtropical environment. Two farming sites were installed on the island of Oahu, one involving students of Waialua High School and the other on a commercial farm. The high school project was carried out as a learning experiment and had wider-reaching community and family impact than was at first envisioned. Students learned techniques of sustainable farming, outreach to the community, marketing, and family nutrition. The project is expected to continue after SARE funding ceases. The commercial growers followed the natural farming system in a one-acre site successfully for over two years. They then decided against continuing the project because of time and financial constraints.

Project Objectives:

1. To establish a natural farming method suitable for Hawaiian growers.
2. To determine efficacy of the system for plant nutrition and in pest and disease managment.
3. To determine cost effectiveness and profit potential.
4. To determine sustainability of natural farming in Hawaii.
5. To educate Hawaiian growers in natural farming methods.


Agriculture in Hawaii is in a transitional period as major export monocropping systems of sugarcane and pineapple are being downsized and replaced by small farms. Small farmers are in need of new ideas and cropping systems in order to compete profitably in the local market. The large plantations, with their long-term, year-round single crops, have sometimes had a negative impact on the islands' fragile environment. Cattle grazing caused loss of native plants and erosion of soil from upland areas. As in most subtropical environments, Hawaiian agriculture is characterized by continuous year-round production without an overwintering period to help control pests and diseases. There has also been increasing reliance on pesticide and herbicide use and consequent loss of natural biocontrol agents. These practices have resulted in higher yields, but have also led to devastating disease epidemics (Thurston, H.D. 1984). Some of the pesticides now in use are under federal review and may not be available in the future. For these reasons, some Hawaiian farmers are considering alternative production methods. Small farmers in Hawaii need new, sustainable, profitable cropping systems that will not endanger the Hawaiian environment. But change is sometimes difficult. Sustainable agriculture is more complex than conventional farming and requires greater levels of effort and skills (Hue and Silva, 2000).

One such system, natural farming, was developed in Japan as an alternative system of sustainable agriculture that preserves the biodiversity and health of the soil and natural ecosystem. It is currently being studied under Hawaiian growing conditions (Farming Organically, 1998.; Practicing MOA Nature Farming in Hawaii, 1998). The MOA natural farming system uses crop rotation, cover crops, and green manures to maintain soil fertility and texture and to manage diseases and pests. This project was designed to demonstrate the sustainability of this method and to inform Hawaiian farmers and gerdeners of its practical value.

Small farmers have a ready local market available for their produce. The average Hawaii market share supplied by locally produced vegetables and melons in 1996 was only 32% (Statistics of Hawaiian Agriculture, 1996). Lettuce, onions, eggplant, and sweet corn all grow well in Hawaii, but local farms supplied only 8%, 10%, and 51% respectively of the total state consumption for 1996. The remainder of the Hawaiian market was supplied by imports. A market for "natural foods" also exists in Hawaii. There are several markets devoted to these products that have a growing clientele. The Down to Earth store in Honolulu bought 80% to 90% of its organically grown produce from California in 1997, but locally grown supply is increasing (Organic: A growing market. Honolulu Advertiser, January 21, 1998). In addition, natural foods and health products are sold in alternative medicine clinics. Vegetables and herbs grown entirely without pesticides or chemical fertilizers often command a higher price than those grown by standard farming methods. Farms operated under the MOA natural farming method would qualify for certification as organic farms. "Organic" is a labeling term that denotes products produced under the authority of the Organic Foods Production Act and the Hawaii Organic Standards Handbook for Certification (from the Hawaii Organic Farmers Association webpage The challenge now is to demonstrate its potential profitability and to inform Hawaiian farmers of its usefulness.


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  • Susan Schenck


Materials and methods:

The project was located in two farm sites. One was Kahuku Farm, a commercial farm at 600 to 700 ft elevation. The other was a high school student project located at Waialua on a site at about 400 ft elevation. Each site was one acre in size. Prior to starting the project, the soils were tested for nutrients and acidity and sampled for parasitic nematodes. The crops selected by the cooperating commercial farmers as being suitable for natural farming and for the local market were: sunflower, ginger, and soybeans. Crotalaria (Sunn hemp var. Tropic Sun), oats, and sudax (sorghum x Sudan grass hybrid) were to be planted as short rotation cover crops. Seeds were purchased through commercial suppliers and were disease and pest resistant varieties. Crotalaria seed was supplied by USDA/NRCS.

The rotation schedule was designed to maintain soil nutrient levels, manage harmful nematodes, improve soil texture, and avoid insect and disease problems. Sweet corn is a heavy user of nitrogen, whereas the legume crops, peanut and soybean incorporated into the soil increase the nitrogen level (Hue and Silva, 2000). Soybean roots also loosen the soil and improve texture (Managing Cover Crops Profitably, 1998). Crotalaria supplies nitrogen to the soil and is known to produce root exudates that are toxic to nematodes (Ochse 1954). Sudax, the other cover crop, has a deep root system that improves soil structure, reduces compaction, supplies organic matter to the soil, and also helps reduce nematode populations (McSorley and Dickson 1995; Managing cover Crops Profitably, 1998). Organic residue from small grains improves the C:N ratio and thus the nitrogen availability over a longer period of time. Oats also help control weeds.

Weeds were controlled by cover cropping, mulching, and cultivator machines or, in the high school site, by hand weeding. The short cropping schedule and the use of resistant varieties kept microbial pathogens and insect and nematode populations from increasing to unmanageable levels. There were occasional problems, which are discussed further in the results section. Frequent monitoring for diseases, insect pests, and nematodes was carried out. The particular crops chosen did not require extensive labor input during growth. Field preparation, planting, harvesting, and marketing were carried out by the cooperators. The produce was sold on the local Hawaiian market or used to supply high school agricultural field days and sales.

An important part of the project was to educate local farmers about the natural farming method. The high school students participating in the project were interested in agriculture and/or came from farming families. Students participated in all aspects of the field trials: planning, planting, weeding, pest control, and harvesting. They were encouraged to use the knowledge gained in this project to begin additional field and science fair projects and to learn about marketing and nutritional value of vegetables.

The cooperating commercial farmers outlined the crops and program that they thought would be compatible with profitable commercial farming. They prepared the land by their usual commercial methods and installed an irrigation system. The program that they followed is described in the results section. After two years however, they found the detailed work involved in keeping up with the natural farming method interfered with their larger operations and they chose to withdraw from the project. The implications of this decision as far as the natural farming method in Hawaii are discussed further on. To advantageously use the funds not needed for the commercial farm site, a research project was installed to provide further information for Hawaiian growers trying to adopt the natural farming method. In this trial, the soil microbial populations and soil nitrogen levels were measured for eight weeks following soil incorporation of four different cover crops in order to give an accurate estimate of the most favorable time for replanting the next crop. The results of this study were compiled and published as a Hawaii Agriculture Research Center report and will be made available to the public.

Media publicity and public outreach about the SARE natural farming project exceeded the original expectations. Field days were held and newspaper articles published.

Research results and discussion:

The project was initiated in January 2000 and continued by means of a one-year extension through 2003. The results are summarized for each year for the two field sites. During the first year the Waialua High School project was installed and placed under the supervision of one of the teachers, Mr. Noel Kawachi, who had a background in agriculture. The students proved to be enthusiastic participants and learned as they continued and as problems arose. A series of crop rotations was carried out beginning with Sunn hemp. This leguminous plant, being a nitrogen fixer, was cut and incorporated into the soil to increase the nutrient levels for subsequent crops. The next seeding of sweet corn and soybeans had problems with bird damage. The corn suffered from insufficient nutrition. Reseeding was necessary and the birds were controlled by hanging lines of shiny metallic CD disks that flashed and kept them away. Eventually, organic mulch was purchased and incorporated into the soil to provide more nutrients for subsequent corn crops. During the year the soil nutrient level was monitored and soil samples were taken to check possible infestations of parasitic nematodes. No other problems were found.

The commercial farm project was installed on one acre of land by the farmers and their laborers. The site was subsoiled and disked according to their usual farm practice. Five tons of dolomite was applied. Overhead irrigation sprinklers were installed. The first crop was Sunn hemp cover crop, which was then plowed into the soil. This was followed by a crop of sunflower. The sunflower crop was not harvested for seed, but was merely cut down. The farming practices followed natural farming methods, which proved to be effective. Two excellent crops were produced without the use of pesticides or fertilizers. No problems with pests, weeds, or nutritional deficiencies were encountered.

For the period January through December 2001, the farming activites and rotational crops were continued at both locations and outreach activities were carried out. The project at the high school was enlarged and more educational programs became involved as the farming project continued. Over 1000 students had at least some interaction with the farm plots, planting, soil testing, weeding, and other activities. The produce grown was used for fund raising for the high school by selling the produce to a local restaurant. They prepared some of the produce themselves and learned about nutritinal aspects of fresh greens in the diet. The need for green leafy vegetables in the diet is not self-evident in many Hawaiian families, so the students took some of the produce home to introduce it to their families. All of the farming practices followed the natural farming methods with no pesticides or chemical fertilizers used. A detailed record of yields of each vegetable produced was kept. Fifteen different kinds of vegetables were produced during the year.

The commercial farmers followed their sunflower crop with oats and then planted a crop of ginger. Their organic ginger crop was featured in an article in Pacific Business News about the growth of organic farming in Hawaii.

During 2002, the third year of the project, the high school project continued. Problems were encountered and most were solved. Bird predation, lettuce leafspot disease, and soil fertility problems were overcome or reduced. Other problems were mites on peppers and eggplants, whiteflies, insect holes in bean leaves, and aphids on peppers. Nonetheless, the farming methods were continued successfully through the three years of the project and can be considered sustainable for Hawaii vegetable production with cover crop rotations. Several additional class projects associated with the original project were undertaken. One was a study of ancient Hawaiian crops and sustainable growing methods that are similar to the natural farming method. Three Hawaii State Science Fair projects were initiated that covered various aspects of the farming methods. Student involvement in the project was enthusiastic from the start.

The commercial farmers, Clyde Fukuyama and Melvin Matsuda, encountered soil-borne disease problems in their ginger crop. They nonetheless harvested enough ginger root to use as seed for replanting. Financial difficulties with their farming business and the necessity of using all their machinery and manpower on their business operations forced them to abandon the natural farming plots. They turned over the SARE project coordination to Dr. Susan Schenck.

During 2003 the high school project continued successfully. The supervisor and students are now experienced and accomplished at carrying out the natural farming practices. The high school staff considers the farm project a worthwhile addition to the school curriculum and hopes to be able to fund its continuing operation. The success of the project was due in great part to the dedicated participation of the supervisor, Mr. Noel Kawachi. He provided continuing careful monitoring of the field plots and enthusiastic support and encouragement to the students.

High school teacher and class involvment increased in 2003. Two Special Education classes with a total of 31 students worked with the farm as a learning project weekly for eight months. Five Science classes (108 students and two teachers) became involved weekly for six months. There were additional class visits over the year as well as frequent visitors (estimated around 30) from the community. Among those were two immigrant Laotian farmers. The Hawaii State Schools Superintendent, Ms. Pat Hamomoto, also visited.

A total of 30 different vegetable crops were produced in plot rotations in 2003. In additin to sales, vegetables were donated to the high school cafeteria, faculty functions, and the Haleiwa Shelter. After four years, the sustainability of this project has been established, Among the particulars learned in the process: the three best nitrogen fixing cover crops were Crotalaria (Sunn hemp), alfalfa, and soybeans. Soybeans were ideal because they are also edible. Most crops did better in the winter season, but soybeans, broccoli, and peanuts did best in summer. Composting was the key to continuing sustainability and for maintaining correct soil pH levels. An increased earthworm population was observed indicating improved soil texture and health. Problems encountered and solved were: weed control, insect (whitefly, ants) control, irrigation methods, and bird predation.

The withdrawal of the commercial farmers allowed the project coordinators to use the funds for a related study that will provide additional information for the public interested in the natural farming method. Field plots of four cover crops, Sunn hemp, pigeon pea, sorghum, and marigold, were installed at the MOA farm in Waimanalo, Oahu. Biomass production, release of the usable nitrogen ions, ammonium and nitrate, and soil bacterial and fungal populations were measured over a period of eight weeks following soil incorporation. These data were compiled, analyzed, and written up as a Hawaii Agriculture Research Center publication to be made public through the state extension service mailings and publication on the HARC website. This publication is attached to the hard copy of this report.

Research conclusions:

The project was designed to establish whether the natural farming method could be adapted to Hawaii's subtropical environment with its twelve month growing season. The soil types farmed on Oahu easily become compacted leading to poor drainage and consequent root diseases. Conversely, nutrient leaching can also be severe. The lack of winter cold period results in pest population increases and severe insect problems. Objectives 1, 2, and 4. addressed these issues. Over the four-year project at Waialua High School with close supervision and attention to details, this farming system proved to be sustainable. The market for organic produce in local stores and restaurants provided sufficient sales opportunities for this small production.

Cost effectiveness and profit potential were to be determined on the commercial farm. The farmers produced a good Sunn hemp cover crop and sunflower crop. However, their ginger suffered from soil-borne disease and did not yield sufficient roots to be profitable. The farmers could not provide the necessary time to carefully manage the rotations and chose to abandon the project. Therefore, no cost studies could be undertaken. The outcome of the project, as far as could be determined, is that the natural farming system is economically very well suited to home gardeners and small vegetable farming operations for local sales. But the time schedules, production deadlines and efficient use of manpower and machinery are not compatible with this system on a larger scale.

The project objective of educating Hawaiian growers about the system was carried out very successfully and will be discussed further. Over the four years, at least 1000 students became involved in the project in one way or another. Many of the students will continue with careers in agriculture or on their family farms. If they apply these practices even partially, there will be an overall decrease in use of chemical fertilizers and pesticides in the state.

Field days and media coverage reached a wider public audience, although exact numbers are not available.

Participation Summary

Research Outcomes

No research outcomes

Education and Outreach

Participation Summary:

Education and outreach methods and analyses:

1. Organic farming blooms into $10 mil sector. September 14, 2001. article in The Pacific Business News. By P. Natarajan.

2. Hawaii State Education Fair. May 21, 2002. Waialua High School open house and natural farming plots open to the public. Attended by over 1000 people.

3. Field Day on the Waialua High School natural farming project site. April, 2002. Announcement and summary of the project and results mailed out to the farming community by the Hawaii State Extension Service.

4. Field Day on the Waialua High School natural farming project site. April 25, 2002. Attended by over 200 people and media representatives. Talks given by Mr. Noel Kawachi and Dr. Susan Schenck.

5. Articles about the field day appeared in two Hawaiian newspapers.

6. Chemical-free crops raise hope: Waialua project could be future of farming. The Honolulu Advertiser, April 22, 2003. By W. Hoover.

7. Soil Incorporation of Covercrop Biomass; Effects on Soil Microorganisms and Nitrogen Levels. By S. Schenck. Hawaii Agriculture Research Center, Diversified Crops Report. February, 2004.

8. Sustainable Agriculture: Chemical-Free Vegetable Production. Hawaii Agriculture Research Center 2003 Annual Report. (in press).

Education and Outreach Outcomes

Recommendations for education and outreach:

Areas needing additional study

This project was designed to adapt the natural farming methods to Hawaii's environment, to overcome the particular problems encountered, and to establish it as a sustainable farming system. In this respect the project was a success. The original field plots are continuing in production four years after initiation. The profitability on a larger commercial farm could not be assessed and the system does not appear to be completely adaptable to that type of operation. However, even though it may not be usable in its entirety, the principles of soil nutrient conservation and replenishment with alternating crops and intercrop covercrops are applicable and useful even if only partially incorporated into commercial operations. Besides this, there are many small farmers in Hawaii that could benefit from adoption of the natural farming system.

This project was intended as a learning and demonstration project and succeeded very well. Further work is needed to assist farmers in adapting their actual operations to the natural farming system. In fact, further funding from the American Farmland Trust was obtained for this purpose. That project "Adoption of Improved Crop and Soil Management Practices to Eliminate Bare-ground Fallow and Reduce Reliance on Pesticides by Hawaiian Farmers" was initiated in August of 2003. The principal investigators are Dr. John McHugh and Dr. Susan Schenck.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.