Determining Optimal Planting Density Per Acre of Dual-Purpose Industrial Hemp with Cover Crop

Commodities

• Agronomic: hemp

Practices

Since the Kansas Department of Agriculture industrial hemp
research program first launched in 2019, farmers in the state
have attempted to produce profitable industrial hemp fiber and
grain crops.  Ninety percent of farmers have failed to
produce profitable industrial hemp crops due to a lack of
knowledge and resources providing guidance to establish on farm
best practices for profitable production.  This has pretty
much been the norm in the North Central part of the United
States.   As with any commodity crop, soil preparation,
nutrient content and planting methodology, harvest and post
harvest processing are critical to profitability.  Research
in these areas have been sparse and fractional.  This has
left the vast majority of commodity producers seeking to include
industrial hemp in their crop rotation at best mildly successful
and at worse a failed industrial hemp producer.  Every
commodity crop producer that we know is looking for another crop
to add into the rotation for both economic and soil
sustainability purposes.  Industrial hemp fiber and grain
cultivars are that other crop, but the resources for success just
aren't there yet.      

The AST Genetics contribution to solving this problem is to
determine, document and distribute the optimal planting density
and best practices used in the production of a high performing
hemp dual-purpose hemp variety when planted into a burned down
cover crop with a no-till seed drill.  Below is an overview
of our trial plan.

Duration- 200 days

Variety planted- AST 530

Planting densities- 15lb, 25lb, 50lb

Data Collection:

Emergence Rate- 21 days after planting. 

Photo documentation-  Plot development photos will be taken
every 30 days of the project and organized into a timeline
relative to each plot.  

Seed yield- Each plots seed will be dried, cleaned and weights
recorded.

Fiber Yield-Each plots fiber yield will be recorded

Field Activity:

Cover Crop-A red clover cover crop will be broadcast
planted 

Burn Down-The cover crop will be chemically terminated 3-5 before
planting the industrial hemp seed

Soil Nutrients-Soil nutrient tests will be taken and granular
fertilizer mix prepared. Granular fertilizer will be furrow
applied at planting.  

Planting- A Great Plains no-till seed drill will be utilized to
drill AST 530 seed at 15lb, 25lb, and 50lb in four separate
replicates on 7.5" centers.  

Irrigation- No irrigation will be used on this project.

Harvest- A Wintersteiger plot combine will be utilized to harvest
the grain from the plots.  A John Deere sickle bar will be
used to cut the stalks and a John Deere square baler utilized to
bale the stalks.

Seed Processing- Seed will be dried and cleaned using a Metra 400
grain cleaner

Overview:

The trial will begin in January of 2024 with the broadcasting of
red clover crop seed at a rate of 10 pounds per acre.  The
cover crop is a sustainable way to add nitrogen and other
nutrient matter to the soil therefore reducing nutrient input
requirements at planting.  It is also a sustainable method
of weed mitigation prior to planting of the industrial hemp
seed.  The clover field will be chemically burned down with
ethalfluralin in early May and the industrial hemp seed planted
three to five days later.  Ethalfluralin is an EPA approved
herbicide for industrial hemp fiber and grain production when
used as a preemergent.  We will plant and apply fertilizer
in four separate five by fifty plots per planting density for a
total of 12 plots using the Great Plains no-till seed
drill.  Each plot will be separated by a three foot walkway.
Plots will be utilized to collect data and conduct field days
throughout the growing season and harvested in the late fall when
moisture levels in the plants are appropriate.  Harvest will
be done in two stages.  The seed will be cut with the plot
combine and a reel header.  The fiber will be cut within a
week of the seed cut.  It will be retted in the field and
baled for transport to our farm to be weighed on a floor
scale.  The seed will be cleaned on our farm with the Metra
grain cleaner and each plots yield will be weighed.

Upon completion of data entry, we will produce a comprehensive
report to serve as a best practices guideline for producing
industrial hemp including a recommendation of optimal planting
density based on the trial data.

Objectives:

1. Determine if fifteen, twenty five or fifty pounds per acre is
   the optimal planting density for fiber and grain production.
2. Document soil preparation, planting, harvest and post harvest
   processing procedures utilized.
3. Equip producers with knowledge and resources by hosting field
   days and distributing a comprehensive report upon project
   completion to attendees of field days and other interested
   producers.