Reducing Pacific Island Growers' Reliance on Off-island Fertilizer Sources Through Improved Awareness and Efficient Use of Local

Reducing Pacific Island Growers' Reliance on Off-island Fertilizer Sources Through Improved Awareness and Efficient Use of Local

Summary

Replacing imported fertilizers with local resources is the highest priority identified by the participants of the Western SARE Subregional Conference held in Hawaii.

Lab and greenhouse experiments were conducted to screen locally produced composts and fertilizers for their N release and plant growth response (Please see results section for more details). Periodically, samples from Island Commodities have been collected to quantify their nutrient content and measure stability of the product over time. Samples of major algae invasive species were collected periodically and analyzed for their potassium content. Research is on-going on other objectives/activities of this project.

Objectives/Performance Targets

1. Enhance the capacity of at least 300 growers, compost producers and other agricultural professionals in Hawaii, American Samoa and elsewhere to evaluate compost quality. 

2. Identify the most important variables influencing the effect of rendered meat products (tankage) on plant growth and mineral nutrition in Hawaii and American Samoa. 

3. Quantify the independent and interactive effect of species, collection location and simple processing on nutrient content and availability of three algae species collected from multiple sites on Oahu, Molokai and Hawaii islands.

4. Ensure dissemination of information from this project to producers and agricultural professionals throughout the Pacific region beyond the project duration.

Accomplishments/Milestones

1. Completed lab incubation study of nitrogen release pattern from four new organic fertilizers.

2. A master student completed lab potassium release pattern using leachate column from algae invasive species.

3. A PhD student completed a greenhouse experiment to examine Chinese cabbage growth response to the application of different algae species at different rates of application.

4. A master student completed field (harbor) experiment to validate lab experiment (heat effect) results, focused on reducing viability of four seaweed species. Also, continuous collection/evaluation of potassium content in seaweed species is on-going with collaboration from the Department of Land and Natural Resources.

5. A master student completed greenhouse trial for sweet potato growth and yield response to application of different seaweed species (Hawaii’s algae invasive species) and different application rates.

6. Continued lab experiments to evaluate solution fertilizer (soluble fertilizers) with high nutrient content using tankage compost to be used for fertigation purposes.

7. On-going lab nitrogen release using leachate column for four new organic fertilizers. The study was intended to complete/overcome limitations in the previous lab cups incubation study.

8. Continued evaluation of local tankage for product stability, maturity and nutrient content.

9. One extension bulletin was published on HanaiAi website:
Amjad Ahmad, T. J.K. Radovich, N.V. Hue, and L.J. Cox. 2013. Hawaii’s
Locally Produced Composts: Nitrogen release and effects on pak choi (Brassica rapa
var. chinensis) growth. HanaiAi (Sustainable and Organic Agriculture Program). http://www.ctahr.hawaii.edu/sustainag/news/articles/V14-Ahmad-LocalCompost.pdf.

Impacts and Contributions/Outcomes

1. Increased demand and utilization of the algae invasive species on the Hawaiian Islands by 10%. Also, increased collaboration work with the DLNR’s algae collection team.

2. Developed biosecurity protocol that reduced concerns of algae spread to other areas.

Collaborators: