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Tel:
+44 (0) 208 7469550
Fax:
+44 (0) 208 7469560
email:
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Disclaimer |
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TAKING TOPSOIL SAMPLES
FOR Topsoil / Landscape Analysis
If soil analysis results are to be of value it is
important that the samples submitted for analysis are representative
of the area from which they are taken.
These guidance notes are issued for clients to assist
them in taking representative samples. If you have a specific planting
failure, a difficult site, or require specific soil analyses, you should
contact one of our soil scientists prior to sampling.
Planting failures are best investigated in situ as
analysis of isolated soil samples rarely identifies the problem. You
can increase the cost-effectiveness of the analyses by having one of
our trained soil scientists to take samples and make relevant soil
and site observations at the same time.
Sampling at Source or After Spreading

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Record the depth of sampling |

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Don't mix topsoil (darker surface
layer) with the underlying subsoil in the one sample. |

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If deeper sampling is needed keep
different soil layers separate from each other. |

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Samples are best taken using a soil
auger but a spade or trowel can be used to take samples when
neither a core sampler nor an auger is available. Dig a hole
to the required depth and sample a 10mm thick slice from the
side. |

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Try to restrict damage and compaction
to the soil sample during collection and delivery. |
Topsoil Sampling Depths

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Turfed areas : samples
should normally be taken from the top 100mm of the soil. |

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Shrub or tree beds : samples
should normally be taken from the top 200mm. Note that back-fill
in tree pits may differ from in-situ soil. |

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In-situ soils to be stripped: full
depth of topsoil (usually 200-300mm deep). |

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Stockpiled material : 1
composite soil sample should be taken from approximately each
1,000m³. Sample from the full depth of the heap as well
as the surface. |
How Many Samples to Take

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One sample may represent up to 1
hectare of land provided that there is no mark ed change in soil
type (colour, texture, stoniness, consistency) or change in management. |

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At least 10, but preferably 20,
cores (sub-samples) should be taken, well mixed and sub-divided
by quartering to provide a composite sample of not less
that 1kg (2kg for particularly stony soils). The sample
should be placed in a clean polythene bag. |

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Don't skimp on the number of cores.
After all, one hectare of land is equivalent to about 1300 tonnes
of soil per 10cm depth. Your sample may be only one-thousand-millionth
at that! |
Taking a Representative Sample

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Soils vary greatly so the first
thing to do is to divide the area up into reasonably uniform
sections. |

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Position on slope, type of vegetation,
plant vigour, soil texture, drainage status or soil colour should
be used to divide the sampling area up into different sections. |

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Areas that have been managed, limed,
or fertilised differently should also be sampled separately. |

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Soils of different types should
never be mixed to form a composite sample. |

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Separate samples should be taken
in areas that have been, or are intended to be, used for different
end-uses or planting schemes. |

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Cores should be taken at regular
intervals along a series of zigzag lines covering the area under
investigation. |

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Avoid ground near gateways, hedges,
paths, waterlogged areas and places used to stack lime or fertilisers. |

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Sampling should not be taken after
recent fertiliser applications or heavy rain. |

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If residues of slow release fertilisers
are present, they may give falsely high values for soil nutrient
content. Remove granules of coated fertilisers before sending
the sample to the laboratory where possible. |

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Don't sample in small areas of soil
that are obviously very different from the general area being
sampled. |

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Don't drop cigarette ash onto samples,
allow dust to blow onto them, or allow dogs or cats to use them
as toilets. Don't laugh, it has happened! |

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When sampling, stones should be
included as these form part of the soil. An analysis would be
incomplete without knowledge of the soils stone content. |
If you have any doubts regarding sampling procedures
please contact
us
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