I’m not a Hazelnut expert, but I own about 35 acres of hazelnut trees in the Pacific NW that I lease out to a professional farmer. First, I would like to mention to Mr. Anderson that good Hazelnuts do float in water. I occasionally glean the orchard after harvest and I float all of the nuts in water to separate out rocks and dirt.
Unfortunately, the farming methods used out here in the NW have almost no resemblance to the environmentally friendly methods described in the video above. All of the orchards in our area are trained to grow like trees rather than bushes. The trees tend to form a relatively tight canopy perhaps 20 – 30 feet tall. Spacing of the trees ranges between 10 to 20 feet. The nuts are harvested by sweeping them off of the ground, which requires very flat, bare dirt below the trees. In order to maintain bare dirt, we regularly spray broadspectrum herbicides (roundup), we flail-mow, and we drag the orchard with box-spreaders to level the ground. Obviously, the bare-dirt method promotes wind & soil erosion. The trees are susceptible to Eastern Filbert blight and moths, so we aggressively prune and spray generous amounts of pesticides.