What is Indoor farming?
Indoor farming, typically referred to as vertical farming, is the practice of growing food in a controlled indoor environment where the crops are stacked vertically to drastically increase the surface area available to the plants as compared to the land occupied.
As a result, an exponentially higher crop yield can be realized due to the optimal use of space.
Ideally, every aspect pertaining to the health, quality and yield of the crops is monitored and controlled, in a process known as controlled environment agriculture (CEA). Factors such as temperature, air quality, humidity, light, water and nutrition are measured and adjusted regularly.
Types of Indoor Farming
Three notable methods of vertical farming exist:
The main method used in vertical farming whereby plants are grown without soil. Plants are submerged in a nutrient-rich solution that contains elements such as potassium, nitrogen, calcium, magnesium and phosphorus.
Hydroponics has been found to increase the per area yield of lettuce by a factor of 11 while still utilizing 13 times less water.
Championed by NASA in the 1990s as a way to grow plants in space, this method involves spraying a mist of nutrient-rich liquid solution within the chambers that the plants are grown suspended.
Studies show that aeroponics uses about 90% less water than the most optimised hydroponics system which make it the most sustainable soil-less growing technique.
A marriage of aquaculture and hydroponics, this method aims to create an ecosystem where plants take in the nutrient-rich waste left by the fish while they in turn filter and clean the water before releasing it back to the pond.
Most commercial vertical farming systems do not use this since introducing an aquaculture component would complicate the farm structure.
Aquaponics is largely meant for slower growing crops and since it still requires nutrients and uses vertical farming, it is not an often-used technique.
Why farm Indoors?
Vertical farming is well known for its astronomical upfront costs. Soil agriculture in comparison is ridiculously cheaper. It’s estimated that a theoretical 10 storey vertical farm in Victoria, South Australia, would cost over 850 times more per square meter than a traditional farm in rural Victoria.
Given that it is prohibitively expensive, why bother with it? There is one answer:
By 2050, the global population is predicted to balloon to 9.7 billion and that should concern us; because to feed these many people sustainably would require, according to the Food and Agriculture Organization (FAO), 60% more food production.
The World Resources Institute (WRI) indicates that to feed the population change between 2010 and 2050, an extra area nearly twice the size of India needs to be farmed. The body posits a couple of solutions, one of which is to “increase food production without expanding agricultural land”.
While vertical farming is costly, it has undeniable advantages – the main one being crop yield. A yield estimate calculates that a hypothetical 10 level vertical wheat farm can produce 1940 tons per hectare which as compared to a global average of 3.2 tons of wheat per hectare – a 600 fold increase in yield.
The main problem with this is that current methods for vertical farming consume energy voraciously. A controlled environment vertical farm that can produce excellent yields is technologically intensive.
The methods used to control lighting, humidity, nutrients, air etc. cause the price of the harvest to skyrocket such that a bread loaf made from wheat grown in a vertical farm would cost $27. The average loaf costs $1.29.
As such most vertical farming companies end up being unprofitable. Therefore vertical farms must surmount the challenge of ungainly start-up costs.
The good news is that the technologies of vertical farming which include climate control, lighting and automation have advanced significantly over the years thus reducing the huge capital costs.
The Technology in Vertical Farming
Plants need light to grow and the lack of sunlight in a closed environment means that a substitute is needed. Vertical farming lighting involves the use of LED technology in order to provide each plant with the exact spectrum, frequency and intensity required for optimal photosynthesis.
These high-tech LED grow lights are also automated and can therefore be scheduled so that the plants are illuminated accordingly. They also produce little heat allowing them to be placed nearer to the plants so as to maximise space utility.
Through the use of cameras and image processing software, a farmer can automate the process of monitoring pest damage on his crops and also detect developmental problems quickly and act fast.
The capabilities of these technologies go so far as to even detect and measure the macroelements such as nitrogen and phosphorus in the plants so that a farmer can gauge the health of their crops, a feat made possible through hyper-spectral imaging technology
Extensive data collection
Smart sensors collect a myriad of data points that inform on the health of the plant. The difference in plant and air temperature, for example, is used to tell whether the stomata in the leaves are open. If open, the plant is ready to start absorbing carbon dioxide.
Similarly, the light level and spectrum as perceived by the plants can be measured by smart sensors and adjusted. As such data analysis plays a big part in vertical farming.
Nutrient delivery systems
Sufficient nutrient dispensation is critical to the growth of the plants. Too much will burn them and too little will kill them. This is a process that can be automated through the use of intelligent nutrient delivery systems connected to an IoT (Internet of Things) system that continuously monitors the farm for optimal growth conditions.
The HVAC (heating, ventilation, and air conditioning) system perhaps plays the most crucial role in an indoor farm. LED lights, though an improvement, still collectively generate a generous amount of heat that can be detrimental to plants. The HVAC conditions the indoor farm and improves airflow, bringing in fresh air from the outside.
HVAC systems can be considered to play the most important role in an indoor farm. LED lights are employed to offer the ideal spectrum of light for growth, but they produce a lot of heat.
Vertical farming is not yet viable and won’t be for quite some time. Despite this, food and resource pressures persist providing an incentive to invest in the field. For now, this remains a technology of the future.