In ancient text various methods are prescribed for soil testing before any construction. Based on the results obtained after performing these methods soil suitability for construction is devised.
These methods are as follows
1. In Middle of land dig a pit of (24x24x24 angulas) or (18x18x18 inches). Use the soil obtained from digging to re-fill the same pit. If some soil remains after re-filling then this land is very good and suitable for construction. If no soil remains then it is not good not bad while if some part of pit remains empty after re-filling all soil it is not auspicious.
2. In second method fully fill the pit after digging as per method 1 with water and walk away 100 steps and come back. If after coming back 2 angulas water get dried then it is not good nor bad, if only 1 angulas or less get dried land is very good and auspicious, while if more then 2 angulas get dried then it is not suitable.
3. In 3rd method dig pit of 1 foot and fill it completely with water. Check the water in pit after 24 hours, if there is some water remaining inside the pit then the land is very good and auspicious. If there is no water left then it is not good nor bad. If pit is completely dry and soil is broken then this land is not auspicious and not suitable for construction.
4. Pit as per method 3 can be used for method 4. In this method some flowers should be put at evening time. Then fill the pit with pitcher full water and see the flowers. If flowers floats above water then the land is very auspicious. If flowers doesn’t float and remain drowned then it is not auspicious, any type of construction on this land is not recommended at all.
There are more methods to test the soil but these are mostly recommended by ancient architects like Maya, Vishwakarma and by Many ancient texts.