Are towering croplands more than high hopes and tall order?
Our world is urbanising at an unprecedented rate. Cities are growing in area and population. 55% of the world’s people already live in cities and the number, as well as the percentage, is rapidly growing, almost by a unit every two years. As cities expand in size and scope, the free spaces available for various activities shrink. Agriculture, particularly crop farming in India is a sector with a disproportionately high employment to product value ratio, implying it employs a lot of people, a large share of the country's population but contributes a diminutive portion to the Gross Domestic Product. Often, owing to seasonal and latent unemployment, a lot of human resource goes underutilised. As agriculture modernises, and semi-automation is introduced, at least a member from each family latently or seasonally-employed elects to migrate towards towns and cities in search of a source of constant employment and steady occupation. A burgeoning urban service sector with expanding blue and grey collar jobs often fulfil their quest. Nonetheless, both rural and urban areas are witnessing steep population growths and demand for food is ever-increasing. Urbanisation, Pollution from Industries and indiscriminate waste disposal, Fragmentation, Loss of fertility due to the reckless deployment of chemicals, and growing Builtup have all shrunk the available, viable agricultural land.
COVID-19 has led to a lot of wastage of agricultural produce in both developing as well as developed nations due to the crumbling of supply chains. Streamlining the flow of produce from farm to table is a major challenge, especially in India, with the presence of a chain of middlemen who add no value, elevate costs for consumers, pay farmers frugally, add an excruciating winding volume to the supply channel increasing chances of wastage, and leech out the economy. In the developed nations, produce often travels ridiculous distances, incurring unnecessary transport costs. It’s not uncommon to come across a tiny packet of a food item manufactured half a world across. Supply chains are complicated for no reason. According to the “The State of Food and Agriculture 2019” report by the UN Food and Agricultural Association, 14% of the world’s food is lost between harvest and retail. It stands to anyone’s reason that producing food close to the consumer saves a lot of quality, quantity, time, labour, and botheration. The problem is with diversity: how do you cater to the diverse, multifarious whims and fancies of modern consumerism where an individual is conditioned to have their sudden-onset unpredictable midnight craving for an oddly-specific food item instantly satisfied? The answer is simple, decentralise agriculture and let (empower) the consumer (to) grow what they want, when they want and where they can. Eat what you grow and you shall always have plenty and never have to be concerned about labels of preferences, whether arbitrary or justified, as organic, non-GMO, pesticide-free, and so on.
That brings us to our final question: How to grow food in cities?
Cities are expanding vertically faster than they are expanding in area. It not only saves space but ensures better connectivity and accessibility. The current urban infrastructural future is of vertical construction and with our resources and lands under great strains, shall likely remain so. The skyline of any developing city is imagined as a cluster of futuristic glass-and-metal skyscrapers, which for that matter are rapidly growing in numbers, so it is pertinent to explore the prospects of cultivation in high-rise apartment blocks and commercial towers.
Skyscraper farms shall curb our dependency on lengthy (in every sense) supply chains, and enable high local customisability. More importantly, they shall save a lot of freshwater, large tracts of forests, and a great deal of pollution. Agricultural usage accounts for 70-90% of our freshwater usage. As population grows, so does the demand for food and the pressure on existing arable land that is mostly eased through deforestation. Vertical infrastructure offers us as new surfaces to cultivate upon. Unlike farmlands, skyscraper agriculture can be modularised, is highly scalable, customisable, and adaptable, and needs lesser protective attendance.
A major challenge though is the availability of Sunlight especially in a region of close-packed high-rise structure. In one of our articles, we discussed how research has shown that most plants adapt well to growing in shade and some thrive particularly well even better than they do when fully insolated. However, in very crowded metropolitan blocks, even diffuse, slant sunlight is scarce, and there are obvious limits to the plant’s coping and adaptive ability. One proposed implementation is to install elevator frames circumscribing the building that alternately raise vegetation of each level to the top to derive its daily supply of direct solar exposure for several minutes. By geometric considerations, a few well-spaced, wide, gigantic integrated residential and farming structures are better than a number of thin, narrow, specific, dedicated units. Simply put, big skyscrapers work better than a cluster of smaller ones. Moreover, mixing tall and medium structures is better than having their distinct individual clusters. Again, we could take a leaf (pun intended) out of nature’s playbook and study the efficiency and suitability patterns of plants with a few, big leaves and those with numerous, small leaflets. Further, a horizontal alternating jagged arrangement of the apartment floors resembling a jenga stack would maximally enhance the effective solar interception. Surface-area to perimeter considerations are crucial here as are plant’s thresholds of productivity under limited insolation.
Drip irrigation, hydroponics (growing crops with their roots immersed in aqueous nutritive media) and avant-garde aeroponics (vertically stacking racks of plants irrigated directly at the root by means of drippers or sprinklers) are not only easier to implement in high-rise apartment, office, and dedicated farming blocks but can also be seamlessly automated using the increasingly prevalent IoT systems that are being integrated in novel urban structures. Automation of everything from irrigation and pesticide sprinkling to solar-optimal orientation shall facilitate the adoption of urban agriculture, making it extremely convenient, accessible, dependable, and even perhaps recreational. Automation shall not only enable integration of technology with agriculture and its optimisation but also integration of various functioning of urban spaces which often overlap. For example, solar photovoltaic facilities can be integrated with farming ones using IoT and Machine Learning which enables the command centre to automatically optimally expose either according to their dynamic demands to the Sun, balancing their requirements and optimising yield and convenience as per specific and changing needs of the dwellers. Such fine tuning is difficult to achieve in facilities spread out in two dimensions. AI has the potential to render agricultural caretaking so hassle-free and self-adjusting as to turn agriculture into a pleasurable act rather than a demanding activity requiring constant vigilance and mindfulness.
Towering urban blocks can be developed as farm cum markets to further facilitate consumer access, an arrangement especially convenient for perishables and short-shelf life items. With microclimatic regulation, new non-natural varieties of foodcrops can become viable and accessible to grow in areas with unsuitable climates, expanding and diversifying the urban platter. Urban agriculture shall also serve to improve the aesthetics and air quality of high-rise structures and check indoor pollution. Plants serve as great sound and dust absorbents both of which are growing menaces in large urban areas.
In urban housing environments, plants are better protected from the vagaries of nature as climate extremes, calamitous and catastrophic occurrences, pests, and plant infections. Owing to proximity, localisation, and flexibility of discreteness and integration, the unique needs of specific crops in specific environments can be met and unexpected demands immediately catered to.
Plants have, over the course of half a billion years, forged numerous symbiotic relationships within and across kingdoms, internalising and prompting environmental tunings. It is time we explore the most ambitious, intimate, and productive symbiosis of the Anthropocene, a pioneering inclusivity that shall lay the foundations of pan-nature planetary development.