with reference to named crops,explain why there have been changes in the types if crops grown in Pakistan during recent years?
There may be several reasons depending on the area in question. Some has to do with colder temperatures pushing the window of the growing season to a smaller window. And the other is water availability. Water is an expensive commodity and with the shrinking of the glaciers, not as much water is available. This can lead to higher salt contamination leading to more salt tolerant species.