<span>Well, I'm pretty sure there are four. The northern and southern hemispheres, and then the eastern and western hemispheres.</span>
The name for such a hole is "caldera" which is a word of Spanish origin meaning "a pot" or a "cooking pot" (thing of cauldron!) - and this word is used because it resembles the shape of this hole.
Often the Calderas are filled with water forming lakes and often there is an island in the middle of the water.
Quality inputs (improved seeds and fertilizers) are essential to raising productivity (yields per unit area planted) under both the rainfed and irrigated conditions. In addition, strong extension and advisory services are important for enhancing the adoption and efficiency of improved inputs.