August 17, 2004: Organic farmers do a great job of
growing organic crops while improving soil health, balancing
a variety of weed and pest management strategies, and using
During the inspection, however, I often find that they have
not thought about what happens to their organic crops during
and after harvest. You may have your grain harvested by a
custom operator, or share a combine with your neighbor. You
may borrow gravity wagons and trucks from a neighbor or relative
to transport your grain to storage units. Any of these practices
may compromise the integrity of your organic crop.
Commingling can occur when equipment used for harvesting
conventional crops is used to harvest organic crops. Equipment,
such as swathers, combines, and balers; transport units such
as augers, conveyor belts, elevators, wagons, trucks; and
storage units including bins, tote bags, and shipping containers,
all have the potential to commingle your organic crops with
conventional crops left in the equipment.
A study done by 2 engineering specialists at Iowa State University
evaluated contamination of a grain crop by another crop left
in the combine with a 45-minute “farmyard intensive
cleaning” and less intensive “field cleaning.”
They concluded that “it’s not unrealistic to remove
about 60 pounds or more of grain, vegetative matter, and dirt
from the combine after the grain tank had been apparently
The National Organic Program (NOP) rule §205.201 requires
that organic farmers and handlers must describe, in their
Organic System Plans, the management practices and physical
barriers they have established to prevent commingling of organic
and nonorganic products. Section 205.272 requires that certified
operations “must implement measures necessary to prevent
the commingling of organic and nonorganic products and protect
organic products from contact with prohibited substances.”
This includes contamination of packaging materials, storage
containers, and bins by synthetic fungicides, preservatives,
Commingling is defined as “physical contact between
unpackaged organically produced and nonorganically produced
agricultural products during production, processing, transportation,
storage or handling…”
In your Organic Plan, you should provide information on how
your crops are harvested, the type of equipment and storage
units used, if equipment and storage units used for organic
crops only, and if crops are custom harvested. You should
describe your post harvest handling procedures and equipment
used. These questions are designed to help you identify potential
problems and develop strategies to comply with the NOP.
What You Can Do
The first thing to do is to identify all areas where commingling
with nonorganic crops or contamination by prohibited substances
may occur. List all pieces of equipment. If they are only
used for organic crops, commingling is prevented. For equipment
that is also used for nonorganic crops, determine what type
of “thorough cleaning” is needed prevent commingling.
Develop a written protocol or list of actions that you need
to take to clean a particular piece of equipment. This will
help you or your employees remember each step. This may be
submitted as part of your Organic Plan, or you may simply
show it to your inspector.
Some pieces of equipment will only need hand cleaning. Others
may need pressure washed or blown out with pressurized air
before organic use. Gravity boxes, truck beds, and other transportation
units, and storage bins and hoppers may need to be swept,
vacuumed, or blown out with compressed air.
For combines, open all trap doors and run the combine empty
for about 15 minutes. Sweep the hopper and use an air compressor
or vacuum cleaner to remove leftover grains, vegetative matter,
and dirt from “hard to clean” areas. Manipulate
the sieves to shake out residues. Purge any leftover grains
by running three to five bushels of organic grains through
the combine before beginning the actual harvest of your organic
crop. (The purged grain cannot be sold as organic or used
for organic feed.)
In addition to old grain, all harvesting and handling equipment
and transport and storage units should be cleaned to remove
bird droppings, rodent feces, insects, dust, and dirt. Ideally,
equipment and transport and storage units should be cleaned
soon after being used or emptied. This prevents future pest,
moisture, rust, and mold problems, and makes cleaning before
use much easier.
Records are an integral requirement for organic certification.
Keep an equipment-cleaning log on a clipboard or notebook
in the machine shed or other convenient location to record
the date, piece of equipment cleaned, and methods used. Keep
a record of equipment purges.
||Type of equipment
||Methods used to clean
||Quantity of crop purged (if applicable)
||How was purged crop used?
Good luck, and have a safe and bountiful harvest!