Since being awarded a DEFRA Farming Innovation Programme grant earlier this year, researchers from the University of Warwick and award-winning ecologists at Baker Consultants have been exploring different aspects of the soil soundscape.

 Earthworms can now be identified from the sound they make moving through the soil and these recordings are being used to try and determine the number of worms present. Part of this project includes collecting and processing thousands of soil sound samples, which we add to our growing international database and then use to develop algorithms for using the sounds recorded as a proxy for soil health.

 The prototype Soil Acoustic Meter (SAM), for which world-wide patents are pending, will aid researchers in collecting this data and eventually be available for commercial sale to farmers, vineyards and estate managers.

 Andrew Baker, founder and managing director of Baker Consultants said: "We have been working for the past 12 months to develop a cost-effective method for assessing soil health through the sounds found underground. We are increasingly finding that a healthy soil is a noisy soil as the worms, insects and even small mammals all make sounds that can be recorded. Our ecoacoustic team has now developed a hand-held device that can make collecting the sounds of soil accessible to all. The principle is simple: the device allows users to place a probe within the ground and record soil sounds and measure the relative health of the soil. "

 Historically farmers assess the numbers of earthworms by manually digging sample pits and then extracting and counting the worms present - a process which is extremely labour and time intensive. The Sound Acoustic Meter will allow large volumes of data to be collected quickly and easily, saving not only time, but money and resources.

 Organisations including First Milk, Yeo Valley, The National Trust and Moet Hennessy have been some of the first to sign up to provide trial sites for the data collection providing a wide range of soil, habitat and management types.

 The development of this device is a natural extension to the innovative work done by Baker Consultants' team and Dr. Carlos Abrahams. Over the last fifteen years ecologists have been using bioacoustics techniques to improve survey techniques for birds, bats and invertebrates improving the effectiveness of surveys for developers, land managers and now increasingly Biodiversity Net Gain projects.

 Dr Jacqueline Stroud from the University of Warwick Crop Centre said "Soil health is fundamental to crop production and the maintenance of soils is vital to global food security. Earthworms are critically important for maintaining soil health across all outdoor cropping systems, helping maintain sustainable crop production. This device will simplify the collection of important data to inform farming practices and potential improve soil health."