I wanted to help with soil testing information, as testing is becoming increasingly important due to rising levels of harmful compounds, for example phosphorus, being leaked into bodies of water such as the River Wye.
By analysing exactly what is in our soil, we can find out whether the levels of these compounds are likely to pose a threat to the environment, or whether we can save farmers money by using less fertiliser and a pH imbalance will affect the availability of nutrients in the soil.
High levels of phosphates encourage plankton growth, which uses vital oxygen, suffocating fish and other plants.
Increasing pressure for farmers to undertake testing in order to find out exactly what is in their soil is part of the sustainable farming initiative.
Whilst many farmers will no doubt already conduct regular testing, there may be smaller farmers who will be testing their soil for the first time.
I have tried to create this simple guide as it is important that the information on soil testing is accessible and available for farmers in my constituency.
Furthermore, knowing what your soil needs will improve yield and reduce fertiliser costs, and managing your soil’s pH will allow it to take up nutrients more effectively.
So, to stop pollution, save the River Wye, save money, and assist our farmers, I hope this guide will help.
If you know of any information that may be useful, then please do let me know via email to officeofbillwigginmp@parliament.uk or by leaving a comment for me.
Also, you are more than welcome to get in touch if you work in soil analysis and wish to advertise your services here or want to offer advice.
Determining the number of tests and samples
About Soil Testing
There are many companies offering soil analysis for farmers, at varying costs and levels of service.
You can either send a sample to a laboratory, or a company will come to your farm and conduct the test for you.
A standard soil analysis will often test for: pH, P (Phosphorus), K (Potassium), and Mg (Magnesium).
It is advised that soil in fields used for field vegetables and horticulture should be tested every 2-3 years, whilst grass and general arable cropping fields should be tested every 3-5 years.
The number of tests will depend on the size of the field, and it is advised that you should conduct one test for roughly every 10Ha/24.7 Acres.
If you choose to send samples to a laboratory via post, then the company should be a member of the UK Professional Agricultural Analysis Group (PAAG), and there are some examples included at the end of this guide.
These tests guarantee a legitimate and accurate test with a quick turnaround.
If you choose to send samples yourself via post, the below instructions will aid you in taking samples to send to the lab.
Testing-by-post
Determining the number of tests and samples
According to Yara, one test is needed for a uniform 10Ha/24.7 Acre area.
But fields are unlikely to be uniform if hedge rows have recently been removed or if different chemicals or compounds have been used.
Therefore, Large fields or less uniform fields ought to be subdivided into approximately 10Ha areas and separate tests taken for each.
Cobb Agri suggest that at least 20 samples are recommended for each test, however some sources, such as the Soil Carbon Project, advise that between 10 and 15 is sufficient.
These samples should ideally be taken in a “W” formation in order to achieve a higher degree of accuracy:
Therefore, for a field less than 10Ha/24.7 Acres, one test is required, which consists of at least 20 samples.
It is worth mentioning that you should avoid taking samples if the ground is very wet, or from areas that have different activity to the rest of the field.
For example, areas where livestock are fed, bonfires have been located, or manure has been kept.
Equally, avoid taking samples from field boundaries as livestock tend to congregate and fertiliser is often misapplied, and avoid tramlines or other compacted areas. For the most helpful results, try not to conduct a test within three months of applying fertiliser, or within six months of applying lime or manure.
Collecting Samples
In order to collect a sample, whilst digging a hole by hand is acceptable, using an auger is the desired option.
There are specialised soil augers for taking soil samples, such as screw, cheese-corer, or pot augers.
For arable land, screw or cheese-corer augers are preferred, whilst pot augers are preferred for grassland.
It is important to use clean buckets and sandwich-style polythene bags when collecting the samples in order to not corrupt the results.
For a typical “nutrient and pH level” test, the samples should be taken at a depth of 10-20cm, however it is important to check the specific requirements of the test ordered.
Deeper samples may be required for land that has been direct drilled or under minimum tillage. For permanent grass, a consistent sampling depth of around 7.5cm is very important, and the samples should not include any vegetation.
Sample Sizes
Having collected the soil samples at a depth of 10-20cm, these should then be mixed carefully in a clean bucket, known as bulking, which will allow for the soil sent to the laboratory to be representative.
Each testing company has a different preferred weight of lab sample, however this will be stated on the order form, so check with the company you purchase a test from.
Typically, the amount of soil required for a specific test will be between 250g and 1kg.
This should be taken from the mix of samples taken from the field.
Sending a sample
You will need to send your mixed samples to the soil analysis laboratory.
Sample bags ought to be clearly labelled with as much information about the field and analysis desired as possible.
The compounds in the soil will degrade quickly, so it is important that the samples are sent as soon as possible after collection, and preferably at the beginning of the week so that they are not in transit over the weekend.
Samples not being sent immediately ought to be kept in the fridge.
Samples can be posted in an envelope if small enough, although many companies have the option of a courier service, so again it is important that you check your order form.
Include the order form in the packaging, ensuring that the testing code is correct.
This code lets the company know which test you desire your soil to undergo.
Your testing company will notify you of the results when the test has been complete.
Testing labs
If you decide to send your sample to a testing lab using the process as described above, there are several companies which offer testing services.
The following PAAG-member companies offer standard pH, P (phosphorus), K (potassium), and Mg (magnesium) soil tests.
Prices are listed per sample.
Hill Court Farm Research Ltd (Gloucestershire) offers a full standard soil suite analysis (P, K, Mg, pH) for £15 + VAT (01452 840693).
Richard Austin Agriculture Ltd (Boston) offers a standard analysis for £9.65 + VAT (01205 722755).
Lancrop Laboratories (York) offers basic pH, P, K, Mg, test for £12 + VAT (01759 305116).
Anglian Soil Analysis (Boston) offers basic pH, P, K, Mg, soil test for £12.79 + VAT (01205 460590).
FAST LLP (Kent) Level 1 includes pH ,P, K, Mg, test for £17.50 + VAT (01795 533225).
FAST LLP (Kent) Level 2 includes pH, P, K, Mg, and extractable nitrate, nitrogen, and ammonium nitrogen, for £26 + VAT (01795 533225).
Testing companies that visit
A number of companies offer sampling services whereby they will travel to your site, conduct sampling, and deliver the results.
This involves less work for you however is more costly.
Cobb Agri (Hereford) offer bespoke Nutrient Management Plans based on soil analysis or GPS-based sampling services. Contact (01981 259995) for a quote.
Edwards Agricultural Supplies Ltd (Little Hereford) offer a site-visit service at a price of £90 + VAT per field up to 50 Acres, plus a small charge depending on the amount of travel. Within this price includes a full written report and recommendations on which products to use on your land (01584 711635).
Alternatives
There are both cheaper and more expensive options available for soil analysis.
Home testing kits are available, which are often cheaper per-test but are likely to be less accurate.
For example, the Palintest SK200 can be purchased for upwards of £370 and includes enough reagent for 50 tests.
At the other end of the spectrum, companies offer tests for other chemicals, giving customers a greater idea of the health of their soil.
For example, Lancrop Laboratories’ (01759 305116) broad spectrum test costs £33.50 + VAT, whilst its broad spectrum soil health (which tests for organics) costs £62.50 + VAT.
Anglian Soil Analysis (01205 460590) also offers a broad spectrum test for £46 + VAT.
In all cases, please do not hesitate to contact a soil analysis company with any questions regarding the soil process. They are always happy to field questions.
Government Documents
The following Government documents may also be of use:
https://www.gov.uk/government/news/new-farming-rules-for-water
https://www.gov.uk/guidance/rules-for-farmers-and-land-managers-to-prevent-water-pollution
Want to help?
If you know of any more information that may be useful, then please do let me know via email to officeofbillwigginmp@parliament.uk or by leaving a comment for me.
Also, you are more than welcome to get in touch if you work in soil analysis and wish to advertise your services here or want to offer advice.
Sir Bill Wiggin MP 