Igneous rocks are caused by cooling of the earths liquid magma and forms granite. Metamorphic rocks are changed by high temperatures and pressure to cause recrystallization of sedimentary rock. Minerals in the sand and silt fraction are the residues of the disintegration of parent material and are primary minerals. The clay fraction are the products of chemical weathers and are secondary minerals.
Soils have neutrients in the soil depending on the parent material.
To grow a crop usually requires the application of fertilizer . Clay types 9.