Soil health may be defined as the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals and humans. This definition highlights the importance of managing soils so that they are sustainable for future generations.
The related term soil quality has a similar definition but refers more specifically to the fitness of a soil for the purpose of growing a crop. Thus, in a viticultural context, soil quality can be thought of as the soil’s ability to support grapevine growth and the production of a crop (with consideration to both yield and quality) without resulting in soil degradation or harm to the environment. It includes the functions of soil such as the provision of a medium for vine growth, the retention and release of water, nutrient cycling and the regulation of biological populations.
The assessment of soil quality should therefore include the analysis of its physical, chemical and biological properties. By conducting a range of field and laboratory analytical tests, grapegrowers can determine if corrective action is required to alleviate any constraints to soil use or if practices are having any beneficial or deleterious impacts on soil quality.
Regular soil monitoring over time using sound sampling and measurement strategies is important. In established vineyards, soil testing is undertaken regularly (i.e. annually or biennially) and there is no single descriptor of soil quality; instead a ‘tool kit’ of indicator tests is used. Results from these tests should be evaluated by comparing them with known benchmark (or optimum threshold) values and vine performance criteria such as crop yield and fruit quality. Such information is used as a basis for making decisions on the need for and application rate of inputs such as fertilisers, soil amendments (e.g. lime and gypsum) and bio-fertilisers/inoculants (i.e. products which contain living micro-organisms).
Read more: Setting benchmarks and recommendations for management of soil health in Australian viticulture (2014)