How to Test Soil
Testing soil for contamination, nutrient concentrations and structure can help determine the impact of health and environmental risks, in addition to the suitability of soil for use as a growing medium. Knowing how to test soil, including best practices and the most cost effective approaches, will ensure the laboratory results of your soil testing and the conclusions made are as accurate as possible.
The most cost effective way to test your soil is to utilise our soil testing kits. Sample containers and a sampling guide are provided, allowing this approach to offer fast, affordable and accurate UKAS & MCERTS testing of soil samples.
How to Take Soil Samples
You've received your soil test kit or purchased suitable soil sample containers and are ready to get started, but need to know how to take soil samples.
Sampling Strategy - This is the process of identifying where to take soil samples (e.g. location and depth), how to take soil samples and what samples will be tested for (e.g. nutrients, contamination, leachates), effectively the step by step of what you're going to do and why. As there are hundreds of factors that can affect where samples are taken, a good rule of thumb to remember is that samples should be representative of the soil you want to assess. We're here to help, so don't worry if you're not sure the best place to take your soil samples.
Following the identification of sample locations and depth, you will need to consider how to take the soil sample. This will include working out the best equipment to use but can include deciding whether to use composite samples or single point samples. Composite samples involves taking sub samples from multiple locations or depths and mixing them together to produce a 'composite' sample, this can provide an average of a wider area, which may be good or bad depending on the desired outcome of your soil testing. As the name suggests, single point sampling will provide a more accurate picture of an area and allow for the identification of nutrient deficiency or contamination hotspots, however, more sampling may be required to test a large area when compared to composite sampling.
Sampling Best Practises - When collecting samples of potentially contaminated soil for contamination testing, Health & Safety should be a primary concern and appropriate Personal Protective Equipment (PPE) should be used throughout the sampling process. To ensure laboratory testing of samples provide an accurate representation of the soil (e.g. garden, waste stockpile or field) you should try to minimise excessive soil disturbance and exclude vegetation from the sample. In addition, for testing of volatile properties it is important to ensure that soil fills the containers with minimal air spaces, while allowing the lid to fully close, to avoid volatile properties being lost. Prior to our collection of your soil test kit or your transportation of samples to the laboratory you should try to keep samples cool and avoid drastic temperature changes wherever possible.
How to Test Soil For Contamination & Nutrients
The identification of contamination in soil, from heavy metals, hydrocarbons, asbestos and other inorganic and organic contaminants, is important in determining the risk to health and the environment.
Heavy Metals (e.g. chemicals) - Heavy metal contamination may originate from the use of traditional pesticides, such as Lead Arsenate, from nearby or on-site agricultural uses. In addition, past industrial and commercial uses are a common cause of heavy metal contamination. These metals can be highly toxic and potentially pose a significant risk to human health. Unfortunately, heavy metals are known to accumulate and persist in the soil for decades after potential contaminative activities have ceased, this can mean that soils that appear uncontaminated may have been impacted over many years.
Hydrocarbons (e.g. fuel & oil) - Storage of heating oil and red diesel on a farm site can lead to contamination, from leaking storage tanks or spillages during use. In addition to petroleum hydrocarbons, Polycyclic Aromatic Hydrocarbons (PAHs) are organic compounds that are released from the burning of organic materials such as paper, wood and vegetative materials. When these materials are burned, the ashes are sometimes used on soils or make their way into soil through atmospheric deposition. It may be unclear at first as to whether these contaminants are present so a risk assessment should always be carried out to determine the potential level of contamination risk.
Asbestos - Often used in roofs of agricultural buildings, asbestos presents a significant risk to human health if asbestos fibres are inhaled, either during redevelopment or when the site is lived on. If an asbestos roof is broken, through general wear on the building over time or accidental damage, the fibres can make their way into soils and present a risk to human health in the future. Carrying out a risk assessment would allow for the analysis of the likely level of contamination risk from asbestos at an agricultural site.
British Standard 3882 (Topsoil) - When sampling topsoil to confirm it meets the British Standard (BS3882), consideration should be given to ensuring that samples are representative of the site. In addition to testing for nutrient properties in the soil, such as Nitrogen, Phosphorus, Potassium and Magnesium, topsoil testing includes the assessment of physical properties, such as texture, stones and sharps, therefore, sampled soil should not be filtered to remove these elements as this could produce an inaccurate result.
Understanding Soil Test Results
Following sample collection and testing, you'll need to understand the results. The accurate evaluation of laboratory test results is a critical part of the soil testing process, especially when soil is being tested for contaminants with the potential to impact human health. Soil contamination test results should be analysed with reference to the site use, e.g. residential, commercial, public open space, to determine the level of risk posed to human health.
Our soil testing services include in-depth analysis of laboratory soil test results, to provide you with a clear, easy to understand and actionable summary and recommendations. If you're unsure about what you need your soil samples tested for or how to test your soil, let us know your requirements and we can suggest a suite of testing that will be most appropriate for your needs, in addition to offering guidance on the best way to sample and test the soil.
Meet Our Soil Testing Consultants
Consultants - Supervised by our Chief Technical Officer, Louis Turner, our fully comprehensive soil testing services, are carried out by highly qualified consultants and combine over 30 years experience with detailed UKAS & MCERTS accredited laboratory testing.
Management - Our wealth of experience in project management, logistics and environmental consulting allows us to provide efficient, friendly and high quality soil testing for our clients. As a company, we believe that helping clients achieve their goals while simultaneously protecting the environment is a true "win-win" situation.
Partners - Our experienced, professional and qualified consulting partners further extend the range of environmental and soil testing services we are able to provide. Our partners include a UKAS accredited laboratory that ensures all our soil contamination and quality testing meets the relevant standards.
Contact Us - Contact us and let us know your requirements, alternatively, if your requirements are more complex, or you're looking for more information about how to test soil or our company, a more formal consultation may be necessary. Following initial consultation we can provide an outline proposal detailing how we can help and the costs involved.