Successful Cacao Establishment through Improved Soil Management

View the project final report

Commodities

• Additional Plants: cacao

Practices

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

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.

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
period.