Hydroponics is a subset of hydro-culture and is a method of growing plants using mineral nutrient solutions, in water, without soil.

Petrology is the study of the origin, composition and structure of rocks.

Haematite, also spelled as hematite, is the mineral form of iron(III) oxide (Fe₂O₃).

Laterites are soil types rich in iron and aluminium, formed in hot and wet tropical areas. Nearly all laterites are rusty-red because of iron oxides. They develop by intensive and long-lasting weathering of the underlying parent rock.

Soil texture is given after the soil formation and it is not a factor of formation of soil.

Alluvial soil is formed by accumulated sediments transferred by the rivers and rapids, so it is amongst the most fertile soils. Alluvial soils are well suited to irrigation which helps in raising a number of crops like rice, jute, sugarcane, wheat, cotton, maize, oil seeds, fruits and vegeta­bles.

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO₃).