****Clay soils, Delta, Central Valley, or anywhere else, are regularly amended with sand and organic mulches anyway, regardless of the irrigation method. So there’s no extra cost there.****
Are you trying to tell me that the amendment process is free? All soils are not created equal, and it can become prohibitively expensive to amend, use expensive drip systems that break down in the elements, maintain the proper depth and spacing and remove and properly wind and clean them up again for the next crop. All that in the hopes of saving some water? Some crops use aerial for ferts more efficiently as well.
****And NO soil is “repeatedly disturbed” once the crop is planted - that’s absurd.****
I take it you are not familiar with raised bed gardening where weeding and clay breaking is a good reason for a hoe.
No, I'm saying that the amendment process is part of unavoidable costs no matter what irrigation method is used. And you talk about high costs - what would it cost to do formal raised bed weeding and clay breaking on ten thousand or more plants?
As far as I know, raised bed gardening methods are not used at all for tractor-maintenanced multi-thousand crop fields, despite the somewhat mounded irrigation beds between tracks. The term has several meanings, such as double-dug French raised beds and other wood-braced highly-sand-amended and partial hydroponic methods. And none of them have anything to do with the requirements of large-scale agriculture.
Whatever. Think what you want, your straw men bore me.