Use of Cover Crops with Medicinal Herbs in North Hawaii

Use of Cover Crops with Medicinal Herbs in North Hawaii

Summary

The highlights of our work are two-fold. The first is the positive experience of three farms working together for a common goal under the guidance of TA Dr. Hector Valenzuela, along with the hired young people. The second is our findings from preliminary data submitted by University of Hawaii College of Pharmacy biochemist, Dr. Bob Borris. Although our project will not conclude until August 2012, we are fortunate to have some preliminary curcumin (from turmeric) data (December 2011) which tell us that the most curcumin was produced by the plots that had weed competition (in lieu of “cover crop”), rather than the control plot (no weed competition). This is what we expected. We have yet to find out about the income stream possible for medicinal herb marketing, and certainly a pilot like this will not provide conclusive evidence, but it is a wise preliminary step. Although we did not get the participation we anticipated for youth labor, we have certainly been successful in presenting a valuable paid farm internship opportunity to Kohala youth. We look forward to the coming months as we shift from maintenance to harvesting, product development, and gathering and analyzing our final data.

Objectives/Performance Targets

The three objectives of this project are:

1) Determine the optimum stress conditions for medicinal plant growth on five tropical medicinal plants (moringa, lemongrass, ashwaganda, turmeric and galangal ginger).

2) Provide additional on-farm income for small, tropical family farms through the marketing of tropical medicinals.

3) Provide local youth with inspiration and knowledge of sustainable agricultural practices through paid farm internships.

Accomplishments/Milestones

The research component of this project is to artificially induce stress conditions in a cultivated environment to determine which scenarios produce the most medicinally potent (and subsequently economically profitable) plant. These stress conditions were to be created through an oat/buckwheat cover crop whose root systems would intentionally interfere with nutrient and water absorption of cultivated medicinal crops.

The first challenge was the expense of this cover crop. The shipping cost for Hawaii was more than the cost of the seed. This is a common and serious problem for farm inputs here in Hawaii. We found a substitute, annual rye grass (non-organic, but not GMO) as easy and cost effective to obtain, and that is what we all used. Unfortunately, that cover crop, which did sprout and begin to grow, did not have a good chance of survival on any of the farms, although it did better on Lokahi Farm (LF) and Kokolulu Farm (KF) than on Kohala Medicinal Herb Farm (KMHF). The annual rye grass could not compete with the weeds and grasses here. We consulted the TA, Dr. Hector Valenzuela, about this, and he said we should consider the weeds as the competition instead of the cover crop, which is what we did. We kept the control plot weeded and allowed the other two plots to be overrun by weeds. All of the farms kept the most noxious weeds minimal for the sake of the rest of the farm. It is interesting to note that some of the most stubborn weeds are medicinal according to traditional Hawaiian medicine. It is important to note that this project uses organic methods such as cover crop, mulching, small plot size, on-farm composting, organic pest control and polyculure.

The next challenge was irrigation. Rainfall and strong winds vary among the three farms. KMHF is wettest, then moving west to the leeward side of the island, albeit only a few miles, the rainfall changes drastically. KF is the next wettest and LF is driest. All three farms had different water sources. KMHF uses a potable tunnel well. KF uses county treated water, and LF uses Kohala ditch water. The prices of this water vary as well. County water runs around $3.60 per 1000 gallons, whereas ditch water costs $0.50 per 1000/gallons. The tunnel well water is free but unreliable during drought, and so county water is used as needed. The irrigation system for LF did not work reliably during windy times, which is most of the time. The pressure could not be set to compete with the wind. Drought conditions were in place for Hawaii Island since the plots were established in March 2011 until around October 2011. The main point here is that water was a variable among the three farms in terms of source and amount, and that was expected from the onset.

We were reasonably uniform with the nursery stock, mainly using the same plant stock to plant in our plots, with the exception of two turmeric replacements on KMHF. KMHF raised the moringa from organic seed (beginning April 2010) and provided small moringa trees and ashwaganda (from organic seed). Both of these stocks were fairly stressed by the time they were actually planted, due to an invasion of the rose beetle (eats every leaf off) and being in pots longer than expected, but they survived well enough to use. KF provided fresh organic galangal ginger root stalk and lemongrass starts. LF provided fresh organic turmeric root stock.

Another challenge was establishing the plots uniformly in terms of mowing “cover crop (weeds)” and putting down the weed cloth. The table attached shows the variation in timing for this.

The main obstacle here is that everyone has other jobs besides farming. While all the farms meet and exceed the USDA criteria for definition of a farm in terms of earning over $1,000/year from farming, none of the participants rely on farming for most of their income. Since none of the participants are independently wealthy, the SARE-funded project always took second priority to earning an income. All the participants are extremely busy people that rely on several income streams. Most are very active community volunteers as well. LF earns the most income farming by attending the farmer’s market every week to sell market garden produce, eggs and value-added products. The result was that coordinating schedules to get the cover crop mowing/placing of weed cloth job done, even with the hired help, was not uniform. However, we believe that in spite of that, we can still learn from the analysis of our data. One need only to look at the plots and can see that the control has the most flourishing plants while the weediest plot has the most stressed medicinal plant stock. Photos will be included in the final report.

Working with the youth has also proved to be beneficial and productive. We have not had any problems with our workers, except that some are more reliable than others. One young man in particular has been very proactive and engaged. He has helped to keep the project running as smoothly as possible and is certainly farm manager material. We have really appreciated his participation. One challenge was the availability of the same youth labor throughout the project, in spite of adequate publicity. Since this was not a full-time or even part-time job, it was difficult to find consistent youth for the entire project as we had hoped to do. Most did not have reliable transportation, necessary given the distances in North Kohala, and most hitchhiked to get to work or else were already doing internships on the farm they worked on. We paid half the $12/hour up front and will pay the other half on completion of the project (when we receive the other half of the grant award). We made a point to use local youth, however, and did manage to get the job done, and we believe provided a valuable exposure to them with this project. That is what they have reported to us and told new recruits. We have engaged over a dozen youth in the project so far. Three have been engaged since the beginning, and two since near the beginning. Our goal was to have the same six youth hired throughout the project. So far most of the work has been weeding with some plant growth data and sampling since October 2011. In the next few months, we will engage the hired help in a wide variety of activities (see timeline).

• table insert in results section of 2011 report
• turmeric results
• project timeline
• herb plot maps
• soil test 1 KMHF
• soil test 2 Kokolulu Farm
• soil test 3 Lokahi Farm
• UH CoPharm Turmeric Abstract

Impacts and Contributions/Outcomes

What has worked out very nicely is our working relationship each other, the youth labor and with our TA, Dr. Hector Valenzuela (University of Hawaii, Manoa, College of Tropical Ag and Human Resources – CTAHR) and biochemist Dr. Robert Borris (University of Hawaii, Hilo, College of Pharmacy). Dr. Valenzuela was always available and helpful in shaping the project as the challenges presented themselves. He continued to remind Kathie, the P.I., that this research project is not being done in a lab or controlled field experiment, and therefore variables are to be expected. Dr. Borris has gone beyond the call of the proposal to offer additional evaluation of the turmeric samples (see attached results). He presented an abstract on samples from our project at the 50th Annual International Phytochemical Society Meeting held here on Hawaii Island December 10-15. (see attached abstract). Our proposal was to check levels of curcumin in the turmeric and citrol in the lemongrass at harvest time, and so we are very fortunate. Another development of our work together is a monthly monitoring of curcuminoids in turmeric throughout 2012. This research is not part of the SARE-funded project but will be valuable, nevertheless, to both the farms and to UH College of Pharmacy.

Dr. Valenzuela noted that one of the most valuable outcomes was the social interaction among the three farms, as this could be a preliminary step for a cooperative. The farm owners have not had any conflict so far, have helped each other when needed and are probably closer friends now than when we started. This is another benefit of the project. The cooperative model is a good one for this region, however, at this point there are no plans of yet to start a legal cooperative. If we ever do, we will have the experience of this pilot project to base our decision on. We will know better the full small farm economic impact of our project once we complete it.

Although we have until November 8, 2013 to complete our project, we intend to conclude it in August 2012. If there is a need to extend it beyond August 2012, we will do so. The main tasks that remain are outlined in the timeline attachment.

Thanks again for supporting our project!

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