Originally Posted by lmyers
I don't buy those numbers. I grew up in Kansas and spent many years assembling center pivot irrigation systems. They use lots of water, and spray it into the air where much of it evaporates and sublimates into the atmosphere. There are efficient ways of irrigating crops, but it is drip irrigation, and unfortunately you don't see it promoted. Seems to me it wouldn't be a bad idea for the government to help subsidize the development of drip irrigation more....
Just went and did a little research and apparently hand8272's numbers are correct. The manufactures of center pivot systems claim new technology allows them to operate at 85-90% efficiency. Although drip irrigation operates at 95% percent efficiency, it requires more labor and maintenance.
I know that south-central Kansas finally instituted water rights laws this last growing season. They have been having a problem with aquifers and springs that recharge the Arkansas River drying up. Last time I visited (Thanksgiving) I saw tons of center-pivot and linear irrigation systems watering their early season winter wheat. There was a 50 mph wind and 25% humidity...... I don't see any way those irrigation systems were operating at 85-90% efficiency....