Vertical Farming

By James Hoorman, Hoorman Soil Health Services

Entering a new year is a time when people look to future possibilities. Farming is changing quickly with artificial intelligence (AI), robotics, and data processing. Another change is how we farm, horizontally versus vertically. Vertical farming is growing crops in stacked layers, often using hydroponics and a controlled environment.

Why the need for vertical farming? Our population is growing about 1% per year, and current estimates are that by 2050, the world will need about 50% more food. In the last 40 years, almost 40% of our arable land used for farming has disappeared or is no longer available for farming. Houses, cities, streets, and roads take up a lot of land that could be used to grow food. By 2050, almost 80% of the people will live in urban areas, and many of these areas will become food deserts without access to quality, healthy green vegetables and crops.

With vertical farming, crops are now being grown in skyscrapers, warehouses, and even shipping containers inside cities and large metropolitan areas. The advantages are many, including about 98% less water needed and 99% less land. A big advantage is reduced transportation and travel time. Crops are grown in tightly controlled areas, with light, temperature, moisture, humidity, and nutrients carefully regulated. Crops are grown disease- and pest-free when closely monitored, and do not need to use herbicides to kill weeds. The disadvantages include supplying supplemental heat, light, and, of course, all the nutrients. Many of these structures use a lot of electricity; however, some do use natural lighting as much as possible. Crops can be grown year-round in a controlled environment, minimizing weather risks (drought, floods, pests). Due to multiple harvests, one acre can be equivalent to 240 acres, depending on the crop.

Vertical farming is not really that new. Babylonians and Romans hung pots in hanging gardens as far back as 2,500 years ago. About 1,000 years ago, the Aztecs used floating rafts on ponds, lakes, streams, and rivers to grow produce, with the roots dangling in nutrient-rich water. It’s a delicate balance to keep plants healthy in confined areas, but with extensive monitoring, it can be achieved. How does it work?

Seeds are planted in a smaller area and grown to a certain size before being transplanted to a larger vertical stacked layers. The entire micro-environment is controlled, including lighting (both natural and electrical), heat or temperature, moisture and humidity, and nutrients (generally liquid nutrients delivered via hydronics). The biggest nutrient plants need is carbon dioxide for photosynthesis, which can be supplemented in a greenhouse to maximize yield. Even oxygen can be diffused to the roots to improve respiration for optimal plant growth. Multiple crop cycles can be grown and harvested throughout the year.

Crops that can be grown this way include many vegetable greens and herbs, such as lettuce (Romain, butterhead), spinach, and kale, as well as herbs like lavender, basil, and mint. Some fruits and vegetables that can be vertically grown include strawberries, tomatoes, cucumbers, and celery. Some experiments are underway with melons, including musk melon and watermelon. Even rice and some small grains are being grown in Singapore today.  

As our land degrades due to erosion, land development, etc., vertical farming offers a new way to grow crops to feed our growing population. There is less water pollution, less or no conflict with wildlife, and food waste is generally limited to 3% or less if everything is controlled. So far, some crops cannot be grown this way, including potatoes, onions, and garlic. For future space missions to the moon and/or Mars, vertical farming will be normal due to space and resource limitations. The biggest issue with vertical farming is lighting and the high electrical needs required to support many crops.

Vertical farming is not just for vegetable crops and grains. A large pharmaceutical company in Bryan, Texas, operates an 18-story facility for vertical farming. They grow 2.2 million tobacco-like plants in 50-foot-high vertical stacks and harvest them to make drugs and vaccines. All aspects of the operation are controlled to prevent pests, disease, or outside contamination.

Vertical farming is highly adaptable to our future increased use of robotics, AI, data sensing, and data processing. Much of this work is repetitive and backbreaking, so it makes sense to use machines that can work night and day. Soon, humans will be working much less physically but thinking and, hopefully, enjoying life much more.