Table of contents:
Service overview
Our top performing foliar analysis service offers a comprehensive range of standard and specialist tests to determine the chemical composition of leaf and foliage samples. This will help identify nutrient deficiencies to boost plant growth, yield and quality.
We provide a comprehensive suite of chemical analyses and tests for leaves and foliage. Tests results can provide important data on nutrient deficiency (nitrogen, phosphorous, potassium and trace elements) and help to monitor the progress of fertiliser regimes.
The laboratory is one of the top performers in Europe for plant analysis, ranked first out of 59 European laboratories in the annual plant analysis proficiency scheme run by the EU’s Protection of Forests Against Atmospheric Pollution programme.
Unlike many commercial analytical laboratories and testing centres, we always run calibrated controls with certified reference material to maintain the quality of our data and assess any significant drift or change in sensitivity. You can be sure that data from our facility will be suitable for detailed research analysis and long-term monitoring programmes, especially for soil improvement programmes.
Standard tests
- Nitrogen, phosphorus, potassium, magnesium and calcium (NPK, Mg, Ca)
- Metals and heavy metals (Al, Fe, Mn, Cu, Zn)
The results reported will indicate the normal and deficient levels of these elements. Additional and specialist tests are available on request.
Find out more detail about our procedures and protocols below.
Overview of procedures
Chemical analysis
The foliage sampling procedure is designed primarily for commercial plantations of Sitka spruce, Lodgepole and Scots pine in upland Britain, but also includes reference to larch and broadleaved amenity trees.
Please complete a Site Record Form for each site sampled. Site record forms should be dispatched with the foliage samples to Alice Holt.
Fertiliser prescription
We no longer offer a fertiliser prescription, but we might be able to help you find a suitable person/company which can provide fertiliser prescription on foliar chemical analysis.
Sampling broadleaved amenity trees
Timing of sampling
Only fully expanded undamaged leaves from the outside of the crown, exposed to full light, should be sampled, from late July to the end of August, when concentrations of the nutrients are steady.
Selection of samples
Leaves soiled by birds must be avoided but dust has little effect on the concentrations of major nutrients, so dusty leaves are usually acceptable.
Nutrient concentrations vary less with aspect and height than between healthy and deficient trees. In contrast, nutrient concentrations in basal suckers and pollard shoots may be high and misleading. Leaves should therefore be collected from a convenient position on the outside of the true crown.
Quantities required
Enough leaves to cover an A4 sheet of paper, but excluding the petioles, should be collected from large or well-established trees. Recently planted trees rarely have enough foliage for this size of sample, so a composite sample from 5-10 trees of each species should be taken.
Age of foliage
There is little point in sampling trees until at least two growing seasons after planting since before then they will not be in equilibrium with the site and nutrient concentrations may still reflect the nursery nutrient regimes.
If there is sufficient variation in vigour and current shoot growth to distinguish good and poor trees, separate samples should be made up from each category. If many trees are involved, replicate samples from each category will aid interpretation. Markedly different vegetation types should be sampled separately.
Dispatching samples for analysis
Leaf samples, fully labelled, should be packed in polythene bags and despatched as soon as possible to Environmental Research Laboratory, Alice Holt. If delay in despatch is likely, the packed samples should be stored in a cool place.
Sampling trees in compartments
Identification of areas to sample
Although compartments can be sampled individually, foliage analysis results will be more useful if they are derived from a sampling programme designed to examine a particular problem. Sampling might for example be aimed to assess or monitor the nutritional status of a certain age class of Sitka spruce on a particular soil type.
Having identified the problem and the crop to be sampled:
- It should then be subdivided into areas of good and poor growth
- Foliar samples should be taken from both these areas as relative nutrient values assist in the interpretation of the results of analysis
- Each good and poor sample should comprise of a set of 5 current years’ shoots for conifers and should be accompanied by a SiteRecordForm(PDF-84K).
Timing of sampling
Samples may be collected at any time of day from the first week in October to the end of the second week in November.
Deciduous conifers and broadleaves should be sampled in late July and August after shoot growth is complete and before needles or leaves begin to change colour.
It is desirable to avoid sampling after periods of prolonged rain because nutrients, particularly potassium, may leach from the needles or leaves. However, this may not always be possible and collection of samples will depend on local weather conditions and previous experience.
Selection of trees to sample
Five typical dominant and co-dominant trees should be sampled to form a composite set of 5 shoots (one sample) within each category.
Age of foliage
Only shoots of the current year should be taken, needles or leaves should not be stripped off the shoot. Exceptions to this are large leaved species i.e. horse chestnut, sycamore. For more details see broad-leaved amenity trees.
Position and size of sample required
Position of sample shoot
Conifers: Shoots should be taken from the first whorl below the leader, excluding any Lammas growth. One shoot is taken per tree.
Broadleaved trees: Undamaged, fully expanded leaves should be collected from the outside of the crown.
Size of sample dispatched in bag for analysis
A sample consisting of five current year’s shoots from conifers is sufficient for analysis, irrespective of the growth rate of the trees sampled. Where shoots are too long to fit in the polythene bag they should be carefully cut in two. Enough leaves to cover an A4 sheet of paper, excluding the petioles.
For more information see broad-leaved amenity trees
Note that:
- Shoots or leaves must be fully exposed to sunlight as shading affects the nutrient content.
- Leaves should be collected from a minimum of 5 trees.
However, where the total number of trees available is small, less sample (than quoted above) can be accepted.
Please contact us if there are any doubts.
Packing and labelling samples
Shoots should be shaken if wet and then packed, even if moist, into polythene bags.
A label, made of durable material filled in with water resistant ink must be included with each sample detailing the:
- Name of the forest area
- Name of the compartment sampled
- Species
- Planting year.
Additionally:
- The box labelled “Treatment/Code” should be utilised to indicate whether the samples are from good or poor areas
- The box labelled “Block” can be used to sequentially number composite sets of samples from the same compartment.
The bag ofsamples from 5 trees should be rolled up with the label near the top and (readable from the outside). The roll should be secured with a moderately tight elastic band. The polythene bags should be neatly but loosely packed into a box.
The weather in the fortnight prior to sampling should be recorded in a letter/note. The main concern would be prolonged periods of rain or drought before sampling as this could affect levels of nutrients in foliage.
Severe defoliation such as caused by Elatobium attack on Sitka spruce can affect foliage nutrient levels and so should be noted on the Site Record Form(PDF-84K).
Fertiliser prescription is no longer offered. We may be able to supply contact details of a person/company offering this service.
The deadline date for results must be completed, allowing as much time for laboratory analysis as possible, but the laboratory endeavours to achieve a 4 week turnaround.
Dispatching samples
All foliage samples should be immediately sent by first class post to:
Francois Bochereau
Environmental Research Laboratory
Forestry Research
Alice Holt Lodge
Farnham
Surrey
GU10 4LH
The outside of the parcel should be marked “PLANT MATERIAL – URGENT” and have the sender’s address and a daytime telephone number clearly visible.
Costs and charges
Standard foliage chemical analysis: £25 per sample plus VAT
We also offer a broad range of specialist tests. Please contact us to discuss your specific requirements so we can provide you with a fully itemised costing.
If you are interested in submitting samples please contact us.
