Progress report for FNC24-1411
Project Information
Rosy Buck Farm is a small scale, sustainability-minded farming venture owned and operated by Randall Buck and Holly Evans. They have successfully grown produce for four local farmers’ markets as well as provided food for a growing CSA membership in the St. Louis area for the past eight years. Production includes dozens of vegetable varieties as well as mushroom propagation, all of which takes place on an intensely cultivated two acres. Rosy Buck Farm's business model focuses on regenerative farming techniques such as cover-cropping, avoiding non-organic chemical applications, and a no-till system in which heavy mulching is used to suppress weeds and build soil.
Prior to owning a farm in central Missouri, Randall and Holly spent three years traveling the country and then the world interning in various farming operations, building a skill set that has allowed them to combine environmentally responsible growing practices with profitability.
While many climate models have
predicted a continued increase in spring precipitation for
central Missouri, that forecast is tempered with the accompanying
prediction of hotter, drier summers. Farmers in this area have
experienced the impact of such summers, as many counties are
frequently determined to be in moderate, severe, and occasionally
extreme drought.
The use of hügelkultur, a
horticultural technique in which a mound constructed from
decaying wood debris and other compostable biomass plant
materials is planted as a raised bed, may help alleviate drought
induced difficulties by more effectively retaining water from
rainfall and irrigation. In a region where 40% of the entire
annual rainfall occurs on the ten wettest days of the year and
the four wettest days have experienced a 35% increase in
precipitation over the past 50 years, a passive water collection
system that can absorb, hold, and gradually release the water
produced in a substantial precipitation event will be beneficial
in both alleviating drought pressure and preventing a large
portion of this region's rainfall being lost as run off.
Solution:
Two types of hugelkultur will be
tested in this experiment; above ground and
inground.
The above ground test sites
each consist of a 40' raised bed; placed perpendicular to the slope of the field
(slope varies from 8.6%-14.3% between sites) and curved towards upslope). These beds will be
constructed with a 22” deep base layer of logs, branches, and
manure will be added, as well as an 8” deep layer of leaf/grass mulch, a 10” deep layer of compost, and finally a layer of soil roughly 3” deep. The two
inground test sites have been placed and constructed in exactly the
same fashion except that the base layer will be placed in a 9” deep
trench.
In addition, two control sites
have been made to the same dimensions and placement but only raised
6” and containing only soil. All six sites will be covered with
3” of leaf/wood chip mulch.
Hugelkultur requires the
saturation of its multiple layers as they are assembled to
promote the breakdown of the internal biomass. The water used in
this step will be documented via a water flow meter.
Two test sites and one control
site will be irrigated regularly to maintain field capacity. This
will be accomplished with existing gravity fed drip irrigation
systems. All test site and control site reservoirs will be
independent of each other to aid in accurate recording of water
usage. These sites will
provide data indicating if the overall gallons of water used in
irrigation is affected by the presence of either type of
hugelkultur.
Two test sites and one control
site will be left unirrigated. These sites will provide data
indicating the extent to which either type of hugelculture aids
in water retention in relation to rainfall alone. Rainfall will
be recorded daily from the time all sites are completed until the
end of the experiment using a rain gauge.
All sites will be planted with an
identical row footage of peas (to be replaced with beans later in
the season), kale, beets, leeks, and winter squash. These plants
will help to more accurately represent the evapotranspiration
occurring in an active farm plot.
Two types of measurements will be
used over the course of this experiment to help quantify the
amount of water in the soil; gravimetric water content and soil
water tension.
The gravimetric water content
will be determined biweekly by collecting soil samples with a
soil probe, weighing those samples, heating the samples to remove
any moisture, and reweighing the samples. This data will be used
to ascertain what percentage of the soil mass is water.
The soil water tension will be
measured by tensiometers. Readings will be taken daily from 3
tensiometers per site. This data will demonstrate how much energy
is required to pull water from the soil (which will roughly
indicate the difficulty plants have in acquiring that
water).
Objectives:
- Determine if hugelkultur facilitates a significant reduction
in the need for irrigation compared to traditional raised beds. - Determine the quantity of water hugelculture can store from
sizable precipitation events and for what length of time that
water is retained. - If the first two objectives are met positively, demonstrate
the construction and uses of hugelkultur through an on-farm
presentation, website and social media, and direct outreach to
local farmers and consumers through Known and Grown STL.
Research
Each of the six hugelkultur sites were laid out using a stake and a 15' length of rope. One end of the rope was secured to the ground using the stake. The free end of the rope was then pulled tight pointing down-slope. While maintaining tension on the rope, a 40' bed site (centered down slope) was paced out by walking and marking the arc created by rope radius. This ensured that all the hugelkultur beds are precisely the same size and shape and oriented to collect runoff from precipitation events.
Two sites will test the effectiveness of hugelkultur beds that have been constructed partially into the ground. These beds were dug by hand to both ensure a uniform 9" depth across the whole bed and to facilitate the sifting of the topsoil, as this soil will be used in the making of the beds and turned out to be rather stony.
The first layer placed in the four hugelkultur sites consisted of large branches, between 4-10" in diameter, cut to roughly 24" lengths. Roughly half of these branches had aged longer than 1 year and consisted mostly of oak, mulberry, redbud, bradford pear, and birch. No cedar or pine was used. These logs were placed parallel to the length of the bed to prevent the exposure of log ends and possible loss of moisture. The space in between these large branches will be filled with smaller branches and manure. The nitrogen-rich manure should aid in the decomposition of the wood as well as fill gaps in the hugelkutur bed that might provide shelter to unwanted animal occupants.
Educational & Outreach Activities
Participation Summary:
On November 17, 2024, Rosy Buck Farm hosted an educational demonstration regarding the benefits and construction of hugelkultur beds. The invitation to this event was sent out to members of the local farming community. An example bed was constructed prior to the demonstration to illustrate the various layers of materials used in hugelkultur, different construction techniques, and the "on contour" nature of this raised bed system. After the presentation, the floor was opened up for questions and discussion, including a local farmer who shared her experience with hugelkultur building and maintenance. Informational handouts that summed up key points and brought attention to next year's experiment to test the water retention of hugelkultur sites were distributed to the participants.
Currently the hugelkultur construction process is being documented in pictures, videos, and journal entries for the purpose of supplementing blog posts.