After further research, the plants were in various stages of growth. The very young plants were just mowed down. The larger plants were pulled and carted away for disposal. Those hoops are everywhere around here these days. They grow many varieties of berries under them, a green house type environment. Only visible evidence of what is growing would be at the end of the rows where the hoop is open and that is plenty easy to camouflage. Drip systems save water, less affected by frost and wind and rain. Very effective.