Maximum Yield USA July 2017 | Page 68

vertical farming GROWING SURFACE AREA IN A VOLUME OF SPACE To maximize space-use (expressed simply as density), growers must maximize growing surface area within a volume of space (growing-specific surface area). In horizontal plane growing such as stacked systems, only one side of the plane is usable. Plants can’t grow upside down very well. They can grow on top, however, and they can grow on vertical sides. Stacked systems waste one side of the growing plane. Look at a horizontal growing plane. You can only use one side of the plane. Growers have only partially redeemed the wasted space by hanging lights on the other side of the plane, but ulti- mately are limited in their growing space (Fig. 1). Flip the horizontal plane on it’s side, however, and you now have a more usable growing surface area (Fig. 2). Usable growing space isn’t the only important factor in space-use efficiency, however. Farms require both growing and access space; these areas are two more opportunities for growers to think strategically about how their farm is set up. Stacked production should configure both growing space and access space separately, while vertical production Fig. 1 66 feature combines growing space and access space into one. Crunching the numbers? Quantify wasted space and space-use efficiency with a ratio that compares production space to floor space. Fig. 2