If water cost is the key concern then surely alternate technologies such as drip-lines, inter-cropping, greenhouses/poly-tunnels, windbreaks and mulch could be explored? Also, selecting less water-intensive crop varieties. Fundamentally, spraying water through the air is a great way to lose a lot of it, both in transit and in evaporation thereafter.
Industrial farmers are a bit trapped in what they can sell and how they produce it. They generally can't change varieties much because the plants they're producing are what the factory wants, and anything outside that expectation will sell for significantly less. Secondly, industrial crop fields tend to be hyper optimized towards using harvesters, which don't easily permit intercropping or things in the field to get tangled. Windbreaks in the form of trees are already common in many areas.
All good points, but kinda tangential. To summarize, perhaps we can agree that there are opportunities for technology to make a substantial difference in the resource efficiency of agriculture, but there remain significant factors effecting inertia and lock-in to existing 20th century industrial agricultural processes which must first be overcome.
