Concern about the agricultural soil resource in England has led to the introduction of a range of measures, which potentially challenge farmers' knowledge about the soil and its management. Our understanding however of how well-equipped farmers are with regard to effectively carrying out more complex and knowledge intensive sustainable soil management practices is limited. Specifically, by drawing on the concept of scientific and tacit forms of knowledge, this paper examines the knowledge of soils held by farmers through analysis of data collected from semi-structured interviews with farmers and agricultural advisors and supplemented with data from an extensive postal questionnaire survey of advisors. The data indicate that, while farmers are technically well informed, they can often lack the in-depth scientific knowledge required to implement more complex practices such as using the nutrient value of manures. They also reveal that, while most farmers have good knowledge of their own soils, their tacit knowledge of soil management can be weak, notably in relation to cultivation. The paper concludes that although farmers' knowledge about soil and its sustainable management appears in general to be well developed there are some areas, which need to be significantly enhanced and as such require both a policy response and further research effort.