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Evaluating Soil Quality and Testing for Soil Health Status

9 December 2021

At grass roots level SAC Consulting consultants are noting a growing interest in soil health from farmers and increasing numbers of questions about what SRUC can offer. Soil health is not just about having a good biological system (lots of worms, ample beneficial microbes to keep the pathogens in check) there are also physical and chemical aspects, and to have soil in ‘good heart’ you need the biology (biodiversity), physics (structure) and chemistry (pH and nutrients) in balance. Healthy soil is vital for food production, animal and human life, and biodiversity. Soil is formed of mineral particles, organic matter and lots of pores; even in compact soil roughly half the volume is what people might think of as empty pores.  However, about half of these pores are filled with air, the other half with water. While soil comes in many types, including clay, silt and sand, it is the structure of the soil that determines how well crops will grow. Physically healthy soils are highly porous and this network of holes and cracks is where the roots and soil organisms live. Porosity also determines how efficiently the soil stores and moves water and how easily roots can grow through the soil. Just by looking at a handful, or spadeful, of soil, you can begin to work out its structure. SRUC scientists and colleagues designed the spade test (the Visual Evaluation of Soil Structure or VESS) to help farmers analyse their soil quality.

Measuring soil health might seem a daunting prospect, but indicators such as earthworm numbers and VESS can give you a measure of soil health. The benefits of improving soil health by integrating the biology, physics and chemistry will pay dividends in maximising efficiency and yields whilst potentially reducing pollution, erosion, irrigation, fertiliser and tillage costs. Any test of soil health however, is simply a snapshot of the status of your field. Large additional benefits are gained by comparing results with fields under similar conditions (so, how good are my soils? What can I expect from my soils?) and with repeated sampling of the same field to see how your soils are changing over time (so, what has been the effect of a management change? Is my management good or bad for soil health?). If you would like to know more about testing your soil health status follow the link below:

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