Advances in assessing nutrient availability in soils

Plants depend on sufficient and timely soil availability of 14 essential nutrients. In order to achieve sustainable and resource-efficient plant production with high yields and minimal environmental impact, soil analyses aimed at assessing nutrient availability should be considered an important and integral part of plant production. Although some methods are promising, there is still an urgent need to evaluate the usefulness of methods for a number of nutrients while developing and validating alternative and novel approaches. One of the most promising methods is diffusive gradients in thin films, which is used to predict the plant availability of e.g. phosphorus, copper and zinc. Multi-nutrient extractants such as Mehlich 3 or calcium chloride are also frequently used and provide general indications of fertilization requirements. For molybdenum and manganese no reliable methods exist. In this chapter, we aim to provide an overview of current methods and recent advances for assessing plant nutrient availability in soils.