| Arable
Soil health: Let’s get physical (chemical and biological) If you want to know how healthy you are, then there are a myriad of tests and tools to help you ‘quantify’ the condition of your body – your blood pressure, your body mass index and your cholesterol level, for example. And now there’s a move to develop ways to quantify the health of your soil, too. n 2016, AHDB and BBRO funded the five-year Soil Biology and Soil Health Partnership. With its focus on soil health, one ambition is to produce a toolkit to assist with its measurement and management. One of the first tasks was to review what could be measured and how practical it was to measure it. The next task was to identify a simple way to bring the most relevant attributes for measurement together – enter the ‘soil health scorecard’. Currently developed in Excel, the team has identified threshold values associated with each attribute. When the results from the various field measurements are entered into the scorecard, a traffic-light system flags whether anything requires investigation (red), monitoring (yellow) or, if things are good, where no action is needed (green). To test the approach, a network of seven experimental sites has been established. One of these is a long-term experimental site at Harper Adams University. Established in 1991, on a sandy loam soil (‘Wick’ Soil Series), the site provides an extreme test for the prototype scorecard. It has a long history of repeat organic material additions (at recommended rates) in a predominantly arable rotation (cereals and potatoes). In fact, cumulative organic matter inputs range from 0 t/ha to 129 t/ha. Five organic material treatments have been applied (Table 1). These include annual
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14 | Farming Monthly | July 2019
applications of cattle farmyard manure (FYM), cattle slurry, green compost, green/food compost and food-based digestate. There is also a control treatment, which has received manufactured fertiliser only. Fertiliser was also applied across treatments to ensure that nutrient supply did not limit crop growth. Table 1. Organic material treatments applied at the Harper Adams University trial site
Initial measurements of topsoil chemical, physical and biological properties were made in October 2017 and a soil health scorecard was produced (Table 2).
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