Advantage Good Agricultural
8.1 Soil and Environment Evaluation
Food grown on any field may be contaminated by flooding, past land uses,
the surrounding environment or trespassers.
This Good Agricultural Practice
All farms growing crops.
What needs to be done
not carry out production in fields or orchards where conditions may lead to an
unacceptable hazard unless the site is managed to minimize the risk.
to do it
Contamination due to flooding
Evaluate production areas
for potential flooding. Flood waters can carry sewage, animal waste and other
contaminants onto the production site. This is a particular concern for fresh
fruit and vegetables that are grown close to the ground and can be eaten raw.
If flooding has occurred, talk to provincial and/or federal agricultural specialists
to discuss safe food options or concerns.
Contamination due to past land
If land is rented, investigate former land use as much as possible
to ensure that the land was not formerly used for waste disposal or for other
industrial purposes that may have left behind toxic residues. If there is a concern,
soils should be tested for contaminants and land use adjusted to comply with test
If the land was previously used for agricultural purposes, review
previous crop history and pesticide use records, if available, to determine if
persistent chemicals (e.g. organochlorines) have been used on site. If they have,
the risk of contamination is higher for root crops. These types of produce may
need to undergo chemical residue testing if grown on this site.
speaking, the risk of heavy metal (e.g. lead, cadmium) contamination in plants
is low. However, the potential for heavy metal uptake varies depending on the
commodity, with the risk being higher for root crops and leafy greens. If there
are concerns about heavy metal residues due to previous land use or the surrounding
environment, test the soil before planting these higher-risk crops. Increasing
the pH of the soil can reduce the risk of plant uptake, as heavy metals are less
mobile and there is less uptake in neutral soils than in acidic soils. For more
detailed information see the Canadian
Food Inspection Agency's Standard for Metals in Fertilizers and Supplements (Table
due to surrounding environment
Inspect and identify the potential for biological
or chemical contamination from adjacent lands. Be aware of the potential risk
from run-off, flooding or wind drift if the production area is near livestock
operations or areas where manure or pesticides are applied. If there is suspected
contamination, conduct a water or soil analysis.
If applicable, assess the
potential for cross-contamination of produce on your operation from leaking, leaching
or overflowing manure storage sites.
Contamination due to trespassers
animal access to fresh fruit and vegetable production areas as much as possible,
particularly near or at harvest times, as fecal contamination carries the same
risk as fresh manure application.
Establish visual, physical or auditory
deterrents (e.g. fencing or noise bangers) to redirect wildlife and minimize the
risk of their entering fields.
Routinely check for outside sources of contamination
from human trespassers, including trash and broken bottles that could contaminate
Communicate regularly with neighbours
and understand the types of activities in the immediate area. If there are any
concerns, adjust planting dates or field locations to minimize the potential for
Re-evaluate potential risks when activities either on the
site or adjacent to the production area change.
Physical buffers such as windbreaks, hedgerows and shelterbelts
can reduce wind-blown contaminants by as much as 30 percent and can minimize the
risk of spray drift.
Did you know?
as physical barriers, grass waterways, ditches, mounds, diversion berms and vegetative
buffer areas can reduce the risk that polluted water will contaminate agricultural
water sources and/or crops during heavy rains or flooding.
If you need an audit
Be prepared for the auditor to:
areas of production for potential for flooding and risks posed by the surrounding
environment and trespassers
- Ask questions about previous land use
Laws and regulations that apply
There are few laws that
directly or indirectly relate to food safety specifically regulating the soil
and environment for agricultural production. The prohibitions in law are generally
against selling food with unacceptable residues or contaminants, rather than prohibiting
certain levels in the soils themselves. Due diligence should influence management
decisions where there is any reason to be concerned that contaminants may exist
in the soil.
The Nutrient Management Act, 2002, S.O. 2002, c. 4 and
Regulation 267/03 requires assessment of existing soil conditions in the development
of nutrient management plans.
Other legislation to be aware of:
Under the Plant Diseases Act, R.S.O. 1990, c. P. 14, s. 14 (b), inspectors may
prohibit the growing of certain plant species for a certain number of years where
causal organisms of a plant disease are found in the soil of any premises.
to 8.2 Pesticide Use