Successful Cacao Establishment through Improved Soil Management

Project Overview

Project Type: Professional + Producer
Funds awarded in 2017: $49,789.00
Projected End Date: 01/31/2021
Grant Recipient: Oahu Resource Conservation & Development
Region: Western
State: Hawaii
Principal Investigator:
Dave Elliott
Oahu RC&D


  • Additional Plants: cacao


  • Crop Production: agroforestry, nutrient management
  • Education and Training: on-farm/ranch research

    Proposal abstract:

    Cacao (Theobroma cacao) is a tropical perennial crop that produces the seeds used to manufacture chocolate, cocoa butter and related
    products. Cacao has economic potential in Hawaii due to the value-added production of chocolate, which can capture premium pricing with
    Hawaii’s established brand value for specialty foods such as coffee, honey and tea. Cacao is typically farmed in agroforestry systems that
    incorporate other crops, including timber and fruit trees, as functional components to provide shade and windbreaks beneficial to the
    orchard’s health and productivity. The productive lifespan of a shaded cacao orchard exceeds twenty years. Mature orchards require low
    levels of inputs relative to many cropping systems, build topsoil through leaf litter accumulation, and provide a canopy that suppresses
    weeds, prevents soil erosion and couples well with efficient micro-irrigation systems.
    Cacao acreage planted in Hawaii has increased more than five-fold since 2010, from just over 20 acres to nearly 100 in 2014, and an
    additional 320 acre equivalents of new plantings are planned by 2019 (2015 Hawaii Cacao Survey published by UH-Manoa College of
    Tropical Agriculture and Human Resources). Cacao orchards reach full production five years or more after planting; therefore, improving
    orchard establishment is a high priority for the foreseeable future of Hawaii’s emerging cacao industry. Cacao establishment is complicated
    by the diverse soil and environmental conditions in Hawaii and the absence of successful cacao farming systems to serve as models for new
    farms. Project collaborators, many of whom farm on degraded agricultural lands, have experienced significant challenges and setbacks
    during the establishment phase due to a lack of published information on fertility and nutrient management guidelines adapted to local soil
    and environmental variables. Failure during the establishment phase creates negative economic outcomes that threaten farm financial
    sustainability and can pose negative agronomic and environmental risks like crop disease and degraded soil health.

    Project objectives from proposal:

    1. Evaluate economic costs and seedling growth benefits of site-specific fertility and nutrient management best practices
    during cacao orchard establishment.
    a. Summarize economic costs (ie. cost of soil testing, amendments and fertility additives) of cacao fertility and nutrient management with
    existing practices on participating producer farms / November 2017.
    b. Establish on-farm trials with five participating producer farms in diverse geographic zones of cacao production on the islands of Oahu
    and Hawaii (aka Big Island) / November, 2017 – March 2018.
    c. Assess the seedling growth benefits of fertility and nutrient management under three treatments: (1) pre-existing farm practice, (2) best
    practices for fertility and nutrient management with application protocol adapted to farm soil and environmental conditions (3) same as
    treatment two plus application of arbuscular mycorrhizae (AM) inoculum.
    i. Conduct chemical soil evaluations at pre-project interval / November 2017
    ? Soil pH, total nitrogen, total carbon, phosphorus, potassium and micronutrients.
    ii. Conduct agronomic and leaf tissue analysis at post-project interval / March 2020
    ? Agronomic: basal diameter, height, precocity .
    ? Plant nutrition (Leaf tissue analysis).
    d. Gather anecdotal feedback and observations from host farms / March 2019, March 2020, and throughout project period.
    Notes: Chemical and plant nutrition analysis will require the collection of samples. We will follow procedures indicated in the USDA
    NRCS’s Pacific Islands Area Soils Technical Note 9 “Protocol for Collecting Soil and Manure Samples” (Feb 2005) for soil sample collection
    and standard protocols for cacao foliar samples. Samples will ship to the UH-Manoa’s Ag Diagnostic Service Center or other qualified
    laboratory for analyses.
    2. Share results with producers and other agricultural professionals.
    a. Employ online survey to gauge cacao farmer familiarity and usage of soil testing, leaf tissue analysis and site-specific nutrient
    management guidelines for cacao / October 2017, March 2019.
    b. Hold three field days to demonstrate effects of soil management on cacao establishment. Field days will be held at host sites, and will
    include presentations from the host farmer(s), two agricultural professionals on featured topic(s), and a tour or hands-on activity /
    March-April 2020.
    c. Present initial findings at the 2019 Hawaii Chocolate and Cacao Conference, which is attended by 100 or more cacao and chocolate
    industry professionals / March 2019.
    d. Publish a fact sheet and informational video / March – June 2020.
    e. Disseminate resources, results and related information via social media networks and producer-to-producer networks / entire project

    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.