Vastu Prescribes different types of soil for people according to different casts(Varna).
Brahmin – White Soil
Kshatriya – Red Soil
Vaishya – Yellow Soil
Shudra – Black Soil
A particular type of soil provides fruits for a particular caste only? However, with the increasing population, it’s almost impossible to select the needed land. Moreover, there are innumerable instances wherein people are seen to be growing & enjoying their life while residing on a plan which is supposedly unsuitable for them as the prescribed criteria.
Black soil is prescribed for Shudra. in south India and Maharashtra, we get plenty of black soil, but industries are growing and working very well. That doesn’t mean that the owners are of Shudra Verna to be successful.
In the olden days, Shudra used to do is casting, refining, and forging metals, leathers to make tools and weapons. These are now performed by machines in industries. So, this is how the logic of Vastu shastra should be applied in modern times