We are on the edge of a revolution. Old methods of harvest → transport → sell are starting to lose acceptance. In Europe and the US, as well as many other parts of the world, there is a growing realization that the way produce is offered to consumers and the methods used to grow plants are not sustainable. The value offering on the plate is not comparable to the value offering from vegetables grown in local gardens. With global awareness of and demand for healthier food has come the realization that cutting delivery times and eliminating waste is a superior way to supply vegetables that meet today’s consumer ideas of freshness and nutrient density. Current agriculture practices consume water and nutrient resources as well as requiring excessive pesticides and herbicides to be effective.
After picking, fruits and vegetables continue respiration. The plant continues to break down stored organic materials (sugars, proteins and fats) that causes loss of flavor, aroma and nutrients. Nutrients are lost as heat and moisture leave the plant. Warm, dry air speeds this process, so cool, humidity controller storage during transport is beneficial. Also proper nutrient supplementation during growth will also slow nutrient and flavor loss. But while the process can be slowed, it can not be prevented. Studies show fresh produce loses its nutrient value quickly after harvest. University of California studies show that vegetables can lose 15 to 55 percent of vitamin C within a week of picking. Some spinach can lose 90 percent within the first 24 hours after harvest. Asparagus, broccoli, mushrooms, peas and sweet corn have a very high respiration rate and will lose nutrition and flavor more quickly than apples, garlic or onions, all of which have low respiration rates. The longer produce has to breathe before it is consumed, the less likely it is to retain nutrients. The Harvard Medical School Center for Health and the Global Environment notes that food transported long distances is not likely to be as nutritious as food grown and consumed locally.
We are entering a new age of supplying living produce at point of sale; vegetables and herbs that are still growing in the media at the time of purchase. The demand for products that are fresh and nutrient packed can be seen in the global resurgence of farmers markets and u-pick operations. But now, large retail chains and home delivery service companies are starting to take this one step further. Check the video below focusing on Metro Europe’s attempt to bring in store farms to reality:
In the US, urban farmers are focusing on delivering living produce directly to the consumers door. Several farmers such Fresh With Edge in Rochester, Minn. are differentiating hydroponic grown greens and herbs by delivering them to customers while still in their vertical production towers. The supply their regular clients with a bare-bone system that operate as a fully contained hydroponic system with a DC water pump to irrigate the plants and an aerator that runs on a same timer. The drip irrigation system is similar to those operating in the greenhouse with the water being supplied from the top. Many locations have enough light that the plants continue to grow on the towers while waiting for picking. Customer towers are swapped out once periodically on a set schedule. They also sell to restaurants specializing in farm to table. For restaurants they deliver towers of herbs and that can be mixed-and-matched with a combination of different plants. The towers allow the client to harvest throughout the week. If they don’t use a whole tower of arugula, the farm will take it back, regrow it and then deliver it again to the client so they don’t have to waste anything.
The biggest market going forward may be individual in-home systems. An individual system consists of a reservoir and a single or multiple towers that can fit in a home. The user will be able to swap out a full tower of produce at a time. They can buy a tower of produce, harvest that over a week to three week period and then when they’re finished with that, swap it out for a new tower of produce.
There are a few hydroponic systems that allow the grower to move produce from grow out site to market while still in the grow media and still living. Bright Agrotech offer the ZipGrow Tower system that allows grows to deploy in small urban farm settings as well as large green houses. Zipgrow towers give the farmer the opportunity to take growing produce directly to the point of sale when it is ready to harvest. Check the video below for a farm tour of a typical ZipGrow greenhouse.
Taiwan Hydroponics Development Co. has also developed a vertical GrowTube system that offers benefits of portability and delivering living produce at point of sale similar to the ZipGrow towers.
THDC GrowTubes have the added features of growing the plants in natural coir fiber and providing superior aeration to the root zone that is critical for growing in hot tropical climates.