Guidelines for Detailed
Soil Surveys for Agricultural Land Use Planning
Table of Contents
- Components of the Detailed Soil Survey
More detailed, property specific soil surveys are sometimes needed
when a land use change (e.g., an official plan amendment) is being
sought that would permanently remove the land from agriculture.
The Planning Act establishes that decision makers such as municipalities
and the Ontario Municipal Board must have regard for the Provincial
Policy Statement of 1997. This statement provides direction on the
protection of prime agricultural areas, and establishes criteria
to be considered when prime agricultural lands are to be designated
for non-agricultural land uses.
The following guidelines provide direction for land resource consultants
and their clients undertaking detailed soil surveys for the assessment
of agricultural crop capabilities and suitabilities. For these guidelines
a "detailed" soil survey is one compiled at a working map scale
of 1:10,000 or greater. These guidelines, or terms of reference,
are a set of basic requirements to ensure that planners, landowners
and consultants have the necessary detailed agricultural land resource
information presented and reported in a standard form in order to
make planning decisions or to advocate for changes to planning decisions.
The need for detailed soil information for some local decisions
often arises from concerns with
- the accuracy of the published soil information mapping, classification,
and agricultural interpretations.
- situations where the published information is too general for
decisions about a specific area.
"Published soil information" refers to the county and municipal
soil reports and maps, and also the Agricultural Capability maps.
These map and report documents are all available from OMAFRA.
Soil Survey Components
- The soil survey should be done according to generally accepted
soil survey procedures and be based on an adequate density and
distribution of soil profile and landscape inspections. A general
guideline is one ground inspection per two square centimetres
on the final map (Soil Mapping System for Canada, Agriculture
Canada, 1981). At a scale of 1:10,000 this is one inspection per
two hectares. Inspection locations and data should be included
with the soil map and report.
The "Field Manual for Describing Soils in Ontario" (Ontario Centre
for Soil Resource Evaluation, 1993) provides guidelines for classifying
soils and the landscapes in which they occur.
- Soils of the subject area should be correlated with the soils
classified in the published soil survey map and report for that
county or municipality.
- Agricultural capability for common field crops (corn, soybeans,
small grains, forages) should be interpreted using the document
"Classifying Prime and
Marginal Agricultural Soils and Landscapes: Guidelines for the
Application of the Canada Land Inventory in Ontario". As explained
in this document, land and soils which are classified as "prime
agricultural land" (CLI classes 1 to 3) have necessary capital
improvements in place or it is physically feasible for the landowner/manager/farmer
to make the necessary improvements. If it is not feasible to make
improvements that would enable mechanized row cropping, then the
land may be considered as less than "prime" (CLI class 4 or 5).
The question of "feasibility" often arises about land with wetness
limitations for which more drainage improvement is required for
productivity to be optimized. Each case must be considered individually.
The Agricultural Drainage System Mapping (OMAF) for the subject
area is a necessary reference to help argue and answer the question
of drainage improvement feasibility.
- If the subject area lies within or adjacent to a larger area
of specialty crop production, then its soil suitability for specialty
crops needs to be evaluated. (Provincial Policy Statement, 1996).
"Specialty crops" refer to fruit, vegetable and other crops grown
commercially in Ontario and which cannot be grouped with the general
"common field crop" types listed above. A definition of "Specialty
crop land" is given in the Provincial Policy Statement. The following
publications and guidelines are useful for evaluating land and
soil quality for specialty crops:
- More recent soil survey reports (Brant, Elgin, Haldimand-Norfolk,
Middlesex, and Niagara) include ratings of soil suitability
for some specialty crops. The ratings published in these reports
may also guide the interpretation of reasonably correlated
soils in adjacent counties whose soil reports contain no such
specialty crop interpretations.
- The publication "A Compilation of Soil, Water and Climatic
Requirements for Selected Horticultural Crops in Southern
Ontario" (Ontario Institute of Pedology Publication, 1989)
outlines general landscape and moisture needs for more than
40 different tree fruit, small fruit and vegetable crops.
It comprises many of the soil principles used to arrive at
the soil suitability ratings given in soil survey publications
cited in (a).
- Irrigation and/or artificial drainage are often necessary,
depending on the site and crop. Climatic regime needs consideration.
The longer the frost free period and the greater the heat
units available, the greater the range and productivity of
crops land tends to support.
- In general, soils which are interpreted to be "prime" (Class
1-3) for the common field crop types of corn, soybeans, small
grains and forages will have viable suitability for a range
of specialty crops. This is most true of sandy and loamy soils.
Clayey soils are suitable for a lesser range of specialty
crops but may still be well suited for some crops.
The Canadian System of Soil Classification; Agriculture and Agri-Food
Field Manual for Describing Soils in Ontario; Ontario Centre for
Soil Resource Evaluation, 1993.
Classifying Prime and Marginal Agricultural Soils and Landscapes:
Guidelines for Application of the Canada Land Inventory in Ontario;
Ontario Ministry of Agriculture and Food, 2004
A Soil Mapping System for Canada: Revised; Agriculture Canada,
Agricultural Drainage Systems Mapping, OMAFRA, 1983
A Compilation of Soil, Water and Climatic Requirements for Selected
Horticultural Crops in Southern Ontario, Ontario Institute of Pedology,
In order to ensure that all of the components for the detailed
soil survey are completed properly, an experienced pedologist should
be retained for any survey work.