Jesus wept blether ! What are you doing to me ? I had a tear in my eye by the end of that video, and it's only 8.00am and I haven't even had a beer yet.

As far as his idea goes it is brilliant, and I can relate to what he says about the water savings, as I had a small citrus orchard on my 19 acre block years ago, with 63 mandarin, orange and tangelo trees.
That cone would not only mean you have to use less water to irrigate but it would retain the water longer where you want it, within the drip-line where the surface/feeder roots are due to cutting the wind drying out factor. Would also cut weeds growing there because the wind-born seeds would not be able to be blown in.

It has always been an issue, getting the right amount of water where you want it and not allowing the area to dry out. Too much mulch means you have to use more water to get it through the mulch to the surface roots. Not enough means it drys out faster.

Great idea, wish I had have thought of it 15 years ago.