The term "Agricultural Region" refers to an area charactrized by homogenity in agricultural conditions, especially of the crops or crops grown, and of scientific dissimilarities from the conditions in adjacent areas which are clearly recognizable. Although, in Bihar the agro-climatic condition is almost similar throughout the state, it can be still divided into three macro regions:
The Drier Central Parts of Bihar, North and South of the Ganges, due to drought conditions, maize takes over.
The Chotanagpur Plateau, wheat loses dominance as 2nd Crop.
