Practical Silvopasture Implementation: A study of the ecological, nutrition, and food system impacts of crop-livestock integration

Project Overview

FS24-363
Project Type: Farmer/Rancher
Funds awarded in 2024: $19,947.00
Projected End Date: 03/31/2026
Grant Recipient: Bearwallow Valley Farms
Region: Southern
State: North Carolina
Principal Investigator:
Nicole Coston
Bearwallow Valley Farms

Commodities

No commodities identified

Practices

No practices identified

Proposal summary:

We have chosen to allow our ducks to rotationally graze in our
apple orchards to receive the benefits of Silvopasture (for both
animal and prevailing fruit crops) while maintaining food
safety.  Our farm has worked with the Henderson County
Extension Service Small Fruit and Vegetable Agent and Livestock
Agents, as well as the Area Specialized Agent for Fresh Produce
Food Safety in Western North Carolina.  Together we
developed a rotational grazing plan that takes advantage of
off-season and post-harvest land.  This plan follows the
90-120-Day Rule for Organic Crop
Manure
 Amendment from USDA that states raw
animal manure must be applied 90 days prior to harvest of the
tree crop and 120 days to any crop that comes in contact with the
ground.8 

Silvopasturing duck in orchards is not only possible but also a
valuable market opportunity for farmers to diversify their
product line while reducing costs of commercial fertilize,
pesticides, and application labor.  According to the USDA, a
farmer can economically manage weeds without herbicides using
silvopasture.  These pastured animals compete with weed beds
for water, nutrients, and sunlight, thereby enhancing tree growth
and reducing weed pressure.15 The economic
value of many conventional fertilization schedules is in excess
of $10,000.  The value of manure is approximately
$0.50/pound but could be double this value considering the
economic worth of improved soil structure, diversity, and
activity of soil organisms that conventional fertilizers do not
provide.16 Fertilize costs have increased
substantially over the past decade and silvopasture is an
effective means to reduce or eliminate these costs. 
Silvopastures create biological diversity and improve water and
soil quality; resulting in improved crop output and quality.
Perennial forage protects the soil from water and wind erosion
and adds organic matter to the soil.  Additionally, ducks
are able to forage extensively and can decrease feed costs by as
much as 30%.

We have selected the Silver Appleyard Duck breed for our farm
because they are one of the best egg-layers in their class and
are excellent foragers with superb mothering skills. 
Appleyards have a lower saturated fat content than other duck
breeds, providing lean meat that is prized by chefs for its
gourmet roasting ability.  Silver Appleyards were developed
in the 1940s by Reginald Appleyard in England.  He created
the Appleyard as a prolific layer that also has size and large
breasts for meat, making it the ideal all-purpose duck. Ducks
yield 74% of their weight as marketable, making this bird more
valuable than other processed poultry. Silver Appleyards came to
the United States in the 1960s, but were not available to the
public until 1984, by 2000, The American Poultry Association
accepted the Silver Appleyard into the Standard of
Perfection.  Today, Appleyards are listed on the
Conservation Priority List and are in danger of becoming
threatened in the United States.  We are proud to raise this
heritage livestock breed and improve market demand for heritage
livestock products. 5,7

Customers are requesting regenerative practices and are going
beyond organic, recognizing the impact farm practices have on our
food system.  This model of silvopasture can also serve as a
community-connection opportunity and result in increased sales
outlets to holistic and local supermarkets.  And as farmland
in Western North Carolina and across the United States dwindles,
it is important now, more than ever, for farmers to increase
per-acre revenue and market viability.

The Silver Appleyard Ducks will serve a dual purpose: as a
high-quality, nutritious marketable product, as well as improve
our orchard management practices.  Duck manure has a
balanced NPK ratio at 2.8:2.3:1.7 while chickens provide only
1.5:0.5:0.8.  Not only do ducks provide a higher percent of
primary macronutrients in a more balanced ratio; but they also
provide a larger volume that is in a form more readily available
for plant uptake than chicken manure.14-15

 

Project objectives from proposal:

Most study designs related to manure application measure the
litter nutrient content rather than its direct impact on the soil
quality and prevailing ability to minimize chemical input. 
In this study, we aim to show statistically significant
improvements in pest prevalence, weed pressure, and/or soil
composition.

Our research uses a paired comparison design and t-test
statistical analysis. We have treatment blocks and control
blocks, approximately 2.3 acres in size.  Each block
contains two plots, one plot of each treatment (treatment and
control), blocks are replicated four to six times across the
field to account for field fertility gradient, and as recommended
by Sustainable Agriculture Research & Education.17

The treatment will include a 6-month rotational grazing pattern
for Silver Appleyard ducks at a rate of 30-50 ducks/acre in
treatment blocks.  Assessments are completed at Baseline, 3
months post-treatment, 6 months post-treatment, and 1 year
post-treatment.  Multiple assessment types and repetitions
are required for this research as soil nutrition and composition
naturally vary within a field and throughout the course of a
season.  Our assessments include the
Pest Prevalence Assessment, USDA’s
In-Field Soil Health Field Assessment, and NCDA&CS
Agronomic Division Soil Testing Section’s Comprehensive Soil
Health Laboratory Test,
Heavy Metal Analysis, and
the Diagnostic Problem Sample Laboratory Test as
needed.  We additionally collect subjective data including
field notes and images.18-19

Research Question

Is silvopastured duck an effective and practical method of pest,
weed, and soil nutrient management in fruit and nut orchards?

  1. Can adding silvopastured duck to fruit orchard management
    system:

    1. Reduce pest pressure/prevalence?
    2. Reduce weed pressure
    3. Improve soil microbiome?
      1. Are any of these changes significant enough to reduce
        or eliminate chemical input?

        1. If so, to what extent?

Hypothesis

The addition of silvopastured duck in fruit tree management will
result in a statistically and financially significant improvement
in one or more of the following:

  1. Pest prevalence/pressure
  2. Weed pressure
  3. Soil microbiome

Objectives

  1. Introduce Silvopastured duck into fruit orchard on test plots
    of approximately 2.3 acres for a 6-month rotational grazing
    pattern.
  2. Collect and analyze data using Pest Prevalence
    Assessment
    , In-Field Soil Health Assessment, and
    Comprehensive Soil Health Laboratory Testing at
    baseline, 3-months post-treatment, 6-months post-treatment, and
    12-months post-treatment.
  3. Analyze and disseminate results widely in the agriculture and
    healthcare fields.

 Data collection methods

  1. Pest Prevalence/pressure

Pest trapping and monitoring is a method of quantitative data
collection as recommended in Integrated Pest Management Systems
(IPM).  This is conducted by our professional Pest Scout, R.
Jordan, who uses a variety of adhesive and pheromone-exuding
traps.  Our Pest Scout then uses insect counts, action
thresholds, and degree-day models to generate a report of pest
prevalence and recommended control solutions.  Our Pest
Scout will collect and disseminate this data to our farm
throughout the data collection period and, ideally, at least one
calendar year thereafter. These traps will be set during the
tight cluster apple-growth stage and hung approximately 6 feet.
off the ground.  Traps are positioned at the interior of the
orchard and kept at least 20 feet apart from each other.

The specific pest species we target will determine the type of
trap and pheromone lures selected.  We use both Delta-style
and wing traps to monitor Codling moths, Oriental fruit moths,
and Leaf-Roller Species (tufted apple bud moth, red-banded
leafroller, oblique-banded leafroller, and the lesser appleworm)
in our orchard.

Below are the trap and pheromone lures used, as recommended by NC
State University:

  • Codling moths Delta-style traps with replaceable interior
    sticky liners and Codling Moth L2 pheromone lures
  • Oriental Fruit Moths: Delta-style traps with replaceable
    interior sticky liners and Oriental Fruit Moth L2 pheromone lure
  • Leaf-Roller Species (tufted apple bud moth, red-banded
    leafroller, oblique banded leafroller, and the lesser appleworm);
    Wing traps instead of Delta traps, which is a more cost-effective
    option for these. These traps consist of a plastic top, a sticky
    cardboard bottom, and a wire frame holding the two together with
    the applicable pheromone lure.20

     2. Soil microbiome

Soil microbiome will be evaluated using both quantitative and
qualitative data collected in conjunction with NC State
Extension, Small Fruit, and Vegetable Agent and encompass
chemical, biological, and physical properties.  We collect
subjective data regarding crop performance, perform a
quantitative Comprehensive Soil Health Laboratory Test,
and use the
USDA Nature Resource Conservation Service (NRCS) Crop Land
In-Field Soil Health Assessment
that evaluates:

    • Soil cover
    • Residue breakdown
    • Surface crusting
    • Ponding/infiltration
    • Penetration Resistance
    • Water-Stable Aggregates
    • Soil Structure
    • Soil Color
    • Plant Root Development
    • Biological Diversity
    • Biopores

We follow collection and sampling guidelines as indicated and
directed by NRCS and are available for full review
here
.18

The Comprehensive Soil Health Laboratory Test (form
AD-12
) is completed in conjunction with the North Carolina
NCDA&CS Agronomic Division Soil Testing Section and approved
by the Soil Testing Section Chief.  Samples are collected
and analyzed for nutrient composition.  We complete a
baseline Heavy Metal Analysis (Form
AD-13
) and follow up with subsequent analysis as needed. Form
AD-2 we use
for diagnostic problem samples, as needed. Lastly, we collect
subjective data regarding general crop performance, visual
nutrient deficiency symptoms, and field images.3

 

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.