Occultation Impacts on Soil Health and Plant Termination in Oregon

Commodities

• Agronomic: corn, radish (oilseed, daikon, forage)
• Vegetables: beans

Practices

• Crop Production: no-till
• Education and Training: on-farm/ranch research
• Soil Management: soil analysis

Occultation tarping has the
potential to transform Oregon’s small farm management practices
in ways that help farmers save money, access in-expensive, easy
to implement strategies to terminate cover crops, and manage
weeds in the field while protecting soil tilth. We want to study
this ‘ground-breaking’ no-till strategy to better understand the
impacts on soil health and plant termination. 

Occultation, “weeding with tarps”
involves laying down a thick, black plastic /vinyl tarp for 4-8
weeks. Under the tarp, the weed seeds germinate in the moist
environment, plants die due to lack of sunlight, and then
decompose back into the soil with the help of the active soil
food web. Once the tarp is
removed, the clean seed bed is planted/seeded and minimal soil
disruption occurs.

Our research question is, “What
effects does occultation have on plant termination and soil
health?” We will contract with OSU Soil Lab to conduct soil tests
encouraged by the Soil Health Institute to measure the effect of
occultation on soil
organic carbon concentration, carbon mineralization potential,
and soil aggregate stability. These are all indicators of soil
health. 

Verdant Phoenix Farm’s team
includes a professional educator / experienced no-till farmer, a
retired PhD research advisor, farm assistant, and technical
advisor / ag professional from Jackson Soil and Water
Conservation District. Our project has significant support
because there are a growing number of organic farmers interested
in no-till, but they are not sure how to terminate plants and
protect soil tilth.

We plan to share our findings
through field days, on-farm demonstrations, and through
interviews on the popular No-Till Growers podcast (reaching over
15,000 listeners weekly), and has over 275,000 YouTube subscribers,
internationally.
Our team will also develop
a “Guide for
occultation implementation: Occultation Protocol for No-Till
Systems in Oregon” to
share the practice in Oregon and beyond.

Project Research Objectives: Our project will determine if occultation
tarping has a positive impact on:

1. Soil organic carbon
   concentration, compared to tillage.
2. Soil carbon mineralization potential
   compared to tillage.
3. Soil aggregate stability
   compared to tillage.
4. Plant termination by
   percentage. Qualitatively measure, through observation and
   photo documentation the percentage of plants terminated using a
   scale:1 = < 10%, 2= >20%, 3= <50%, 4=> 50%,
   5= >90%

Education Objectives:

Objective 1: Develop case
study, record observations, photo document, and record impact
data on soil health, plant termination, and crop yield over the
course of the project.

Objective 2: Establish
educational field tours to demonstrate occultation techniques,
impacts, and benefits to producers, gardeners, land managers, and
ag professionals.

Objective 3: Plan, design,
and write a fact sheet and publication to serve as a
“Guide for occultation
implementation: Occultation Protocol for No-Till Systems in
Oregon”. We will work
with the project team, our technical advisor, research advisor,
ag professionals from SOU, JSWCD, and OSU Small Farms to
collaboratively develop content and publish the
Guide for use by other farmers and producers.
(Letters of support included) This Guide will be available in
print (at least 200) and our team will pursue publishing the fact
sheet through OSU Extension.

Objective 4: Present
findings through in-field demonstrations and presentations for
OSU Small Farms program, OSU Small Farms Conference, Jackson Soil
and Water Conservation District (JSWCD) workshops, OSU Land
Steward classes, Friends of Family Farmers, and others when
requested. At least 100 people will attend. 

Objective 5: Print and
distribute fact sheet / "Guide" through ag partners, technical
advisor, and other community partners so that over 200 copies are
provided to interested producers and ag professionals to increase
the impacts of this research and broader adoption of the
practices.

Objective 6: Prepare and
deliver an online workshop / podcast to disseminate project
findings via “No-Till Growers” podcast online. No-Till Growers
have an active listening audience of approximately 15,000 weekly podcast listeners and 275,000 YouTube subscribers,
internationally.  No-Till Growers have committed to
supporting this project (letter included) and their goal is to
help promote and share no-till strategies so there is greater
adoption of the practice.