Enhancing Phytonutrient Content, Yield and Quality of Vegetables with Compost Tea in the Tropics

Project Overview

SW07-073
Project Type: Research and Education
Funds awarded in 2007: $162,500.00
Projected End Date: 12/31/2011
Region: Western
State: Hawaii
Principal Investigator:
Dr. Theodore Radovich
University of Hawaii, Manoa

Annual Reports

Commodities

  • Agronomic: potatoes
  • Vegetables: cabbages

Practices

  • Crop Production: nutrient cycling, organic fertilizers, application rate management
  • Education and Training: demonstration, extension, farmer to farmer, networking
  • Production Systems: general crop production
  • Soil Management: organic matter, soil analysis, nutrient mineralization, soil quality/health

    Abstract:

    Water-based extracts of compost (compost “tea”) have long been recognized as potentially valuable in promoting plant growth. Recent innovations in production and application have popularized it’s use among food producers, landscape managers and other interested in promoting plant health. This renewed interest in compost tea has made the input fairly controversial, and it is often presented as either a “Silver Bullet”, or conversely, “Snake Oil.” Like most other historically used agricultural inputs, compost tea is neither. Unfortunately, our ability to effectively employ compost teas to their full advantage is severely limited by our poor understanding of the interactions between compost type, crop and environmental factors as they relate to plant yield and quality, particularly under tropical conditions. These gaps in our knowledge limit the efficacy of compost tea applications on the farms that currently employ this strategy, but seriously restrict the extension and adoption of compost tea technology to conventional farms that want to improve the sustainability of their operations.
    This project engaged farmers, researchers and industry professionals to address these gaps in our knowledge through a series of on-farm trials and educational activities in a broad range of tropical island environments to achieve the following objectives:
    1) Quantify the independent and interactive effects of compost quality extraction method and crop management on yield and phyto-nutrient content of model root, fruit and leaf vegetables.
    2) Determine, at the whole-farm level, the effect of compost tea applications on yield, phyto-nutrient content, and profitability with commercial vegetable operations on three islands in Hawai’i.
    3) Build and enhance the capacity of at least 300 growers to effectively employ compost tea to increase vegetable yield and phyto-nutrient content on their farms.
    In addition to novel scientific research, peer-reviewed publications and extension bulletins, the activities under each of these objectives has provided for the training of hundreds of farmers through on-farm workshops and farmer-to-farmer networking, and the development of a region-specific compost tea manual. As a result of these products, we have documented: 1) Improved understanding of the ecological processes involved with successful management of sustainable agricultural systems, 2) Successful adoption of compost tea technology by workshop participants and other growers engaged in project activities and 3) Increased partnership between researchers, farmers and industry professionals.

    Project objectives:

    This project engaged farmers, researchers and industry professionals to address strategic gaps in our knowledge and resource base through a series of on-farm trials and educational activities in a broad range of tropical island environments. These activities to achieve the following objectives:

    1) Quantify the independent and interactive effects of compost quality extraction method and crop management on yield and phyto-nutrient content of model root, fruit and leaf vegetables.

    2) Determine, at the whole-farm level, the effect of compost tea applications on yield, phyto-nutrient content, and profitability with commercial vegetable operations on three islands in Hawai’i.

    3) Build and enhance the capacity of at least 300 growers to effectively employ compost tea to increase vegetable yield and phyto-nutrient content on their farms.

    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.