Proper sampling and analytical techniques are critical to accurately
determine the nutrient content and other properties of materials
applied to the land for the purpose of improving the growing of
agricultural crops. Proper techniques have always been important,
but they are now a legal requirement under the Nutrient Management
Act, 2002. The techniques described in this document are
intended to meet the requirements of the regulations under the
Act. They can also provide guidance for other sampling and analysis
requirements with similar goals.
In this document a nutrient management plan required by the regulation
for a Farm Unit will be denoted as an NMP. A nutrient management
plan required for the application of non agricultural source materials
(NASM) will be denoted as a NASM Plan.
1.1 Background to Act and Regulations
The Nutrient Management Act, 2002 provides for the "management
of materials containing nutrients in ways that will enhance protection
of the natural environment, and provide a sustainable future for
agricultural operations and rural development."
The regulations that have been developed under the authority
of the Nutrient Management Act, 2002 provide particulars
on how this management is to occur. These regulations apply to
land applied nutrients from all sources, including commercial
fertilizer, manure and other agricultural source materials, and
non-agricultural source materials (NASM) such as sewage biosolids
and paper biosolids. A key component of the regulations is the
requirement for a nutrient management plan. There are two types
of nutrient management plans: NMP's and NASM Plans. To complete
a meaningful nutrient management plan, it may be necessary to
know the concentrations of nutrients and other parameters in both
the soil and the materials that may be applied to land.
The regulations lay out what materials need to be sampled and
analyzed, how frequently they need to be sampled, and which parameters
need to be measured. These are minimum requirements. It may be
desirable to sample more frequently, or to analyze for additional
parameters, to optimize the management of land applied materials.
1.2 Health and Safety
There may be hazards associated with the physical act of sampling
or with handling materials that could contain toxic material or
pathogens. It is the responsibility of the sampler to have taken
all necessary precautions and to act according to all applicable
health and safety regulations pertaining to the sampling site
and specific situation.
1.3 Sampling Frequencies
Soils may be sampled for two different purposes: to assess the
initial nutrient concentration in the soil which will guide the
application of nutrient containing materials for agronomic and
environmental purposes, and to determine the acceptability of
the site for receiving the particular material with respect to,
for example, regulated metal content and pH.
184.108.40.206 Soils Receiving Nutrients
Persons applying nutrients to fields where a NMP or a NASM Plan
is required, must collect a representative soil sample from each
field (or section of field) as part of developing the nutrient
management plan, and then at least once during each five-year
period for subsequent NMP's. The results from analyzing these
samples are entered into the nutrient management plan.
For NASM Plan's the soil samples used to develop the nutrient
management plan must have been taken within the previous 5 years
prior to the date that the NASM is to be land applied.
As a best management practice, in fields where nutrient levels
may fluctuate widely within the five year interval, it may be
appropriate to sample the soil more frequently than is required
by the O.Reg 267/03. This situation can occur on sandy soils where
crops that are removing large amounts of nutrients are grown.
Silage corn, forages and processing tomatoes all remove large
quantities of potassium from the soil, therefore, soil test levels
can decline quickly to the point where yields are reduced.
Soils must be analyzed for soil pH and, if the soil has a pH
below 6.0, for buffer pH. They must also be analyzed for available
phosphorus (using the sodium bicarbonate extractant) and available
potassium (using the ammonium acetate extractant). In addition,
the sample may be analyzed for available magnesium, nitrate nitrogen,
or the manganese and zinc availability indices.
It is necessary to know the available phosphorus concentration
of a soil prior to applying nutrients so that application rates
and setback distances can be properly determined. The soil must
have been sampled and tested for sodium bicarbonate extractable
phosphorus content and pH within the five years immediately prior
to applying the nutrients to land.
220.127.116.11 Soils Receiving Non-Agricultural Source Materials
Persons applying non-agricultural source materials must, in addition
to the nutrient analyses, have representative soil samples analyzed
for the total content of each of the eleven regulated metals (Table
1.2). These soil samples must have been collected within five
years prior to the application of non-agricultural source materials,
as part of the preparation of the NASM Plan
In the regulation, the maximum allowable metal concentrations
in soils receiving NASM are based on the "mean metal content
of uncontaminated Ontario soils and approximate an upper level
of background concentrations ". For some soils, one or more
metal concentrations may already exceed the maximum allowed in
the regulation. It is therefore necessary that soil testing be
conducted prior to the application of NASM to determine the suitability
of the soil. Samples collected as per Section
2.1 of this document shall be analyzed for the eleven metals
listed in the regulations.
Summaries of acceptable analytical methods are presented in Section
Table 1.1 Standards for Regulated Metals in Non
Agricultural Source Materials
| Aqueous Material<1% TS1
|| Non-aqueous Material
| Aqueous Material<1% TS (mg/L)
|| Non-aqueous Material
1 TS denotes total solids.
2 dw denotes dry weight.
Table 1.2 Maximum Permissible
Metal Addition to Soil Receiving NASM and Maximum Metal Concentrations
Allowable in Soil Receiving NASM
|| Maximum Metal Addition to Soil Receiving NASM
|| Maximum Metal Concentrations Allowable in Soil
Receiving NASM (mg/Kg soil, dw1)
1 dw denotes dry weight.
1.3.2 Non-Agricultural Source Materials
Non-agricultural source materials must be of an acceptable quality
to be land applied, with respect to regulated metals, and, if
required, fats, oil and grease (FOG), boron, sodium and pathogens.
Category 2 and Category 3 NASM as defined in O.Reg 267/03, must
be sampled and analyzed at least as frequently as specified in
the regulation. Category 1 NASM, as defined in O.Reg 267/03, does
not require sampling and analysis unless the application rate
exceeds 20 tonne per hectare per year in which case the sampling
and analysis would need to be done for phosphorous and nitrogen
to determine the appropriate nutrient application rate. The requirements
to sample and analyse for pathogens apply only to sewage biosolids
and NASM containing human body waste (e.g., fecal material). In
the case of Category 3 NASM that is not sewage biosolids or contain
human body waste, pathogen testing may be done to determine if
the NASM is CP1.
Where a reference is made to sewage biosolids or a material that
contains human body waste, it includes materials that result from
the processing of materials that include human body waste or sewage
1.4 Averaging of Results
Where a material is required to be analyzed for regulated metals
or pathogens, the concentration of metals or level of pathogens
in the material is considered to be the average, or mean, of the
concentrations in the four most recent samples. This allows for
any variation that may occur in sampling or analysis of the materials,
while maintaining protection of the environment. Metal concentrations
are calculated as a simple arithmetic mean, where the concentrations
of each regulated metal in the previous four samples are added
together and the resulting total is divided by four. Pathogen
levels are calculated as the geometric mean where the concentrations
of each pathogenic indicator in each of the previous four samples
are multiplied together and the fourth root of the resulting product
Where the mean concentration of any parameter exceeds the allowable
concentration, and the generator still intends to land apply the
material, the generator has the option of re-sampling the material.
This is done by continuing to take representative samples with
an interval between samplings of at least two days. The analytical
results are then used to calculate the mean value. Sampling can
continue on this basis until the mean value of all sample results
within the previous 4 months is within allowable limits for all
parameters. This method is for use where a large value is skewing
the mean, and that value may be due to a spurious analytical result.
1.5 Sampling Locations
Samples that are being collected for total solids, nutrients,
regulated metals and if required, FOG, boron and sodium analysis
must be collected at the location where the material is generated
and before it is transported to the land application area [or
agricultural operation.] This could be the generating site or
storage. This is to provide the farmer with the best possible
estimates of concentrations of the parameters measured.
Samples of material that are to be analyzed for pathogens may
be collected at a location immediately after the treatment process
in the liquid form. Liquid samples are most homogenous at this
point. For solid NASM the samples may be taken immediately after
the treatment process or later in the process.