Question

why is irrigation harmful in areas of poor drainage

Answer 1

 If there is poor drainage then the water will not seep into the ground in time and accumulation of water will result in the spoiling of crops.

Answer 2

Irrigation of the necessary water in the harvesting land,is very necessary for the crops.But it should be done in a measured amount.

Because, excessive amount of irrigated water can damage the that's why we need a good drainage system to extract the excessive amount of irrigated water to prepare the water damagethat's why we need a good drainage system to extract the excessive amount of irrigated water to prevent the water damage.

And, that's why a poor drainage system can cause harmful results during the water irrigation in the harvesting lands.