Clod crushing is a principal problem with soils of high clay content.
Therefore, there is a need for determining the conditions for clod breaking and
clod crushing. The objective of the work was to develop a special purpose tool
for single clod breaking both by rigid support of the clod and by a single clod
supported by soil and to develop a machine for clod crushing. Furthermore, the
purpose was to determine the relationship between the specific energy
requirement for clod crushing in the function of soil plasticity and the soil
moisture content by the means of the developed tool and machine. The main
result of the experiments is summarized in a 3D diagram where the specific
energy requirement for soil clod crushing is given in the function of the
moisture content and the plasticity index for different clay soils.