Onward and upward

The government should come up with policies to incentivise vertical farming

With landholdings shrinking to unviable dimensions and conventional agriculture becoming unprofitable, vertical farming has begun to attract attention as a lucrative mode of crop cultivation. This innovative system of farming involves growing plants in containers stacked on shelves attached to walls or hung from vertically inclined frames or pillars, allowing enough space for the plants to grow to their full height and the light to reach each plant. Growing crop plants on rooftops, balconies and other portions of the multi-storey urban buildings is also viewed as part of vertical agriculture. Th best results are, however, obtained when such cultivation is done indoors or in polyhouses where environmental conditions can be controlled. The basic objective of vertical farming is to accommodate the maximum number of plants in minimum area by utilising upward, rather than horizontal, space.

However, this style of crop husbandry is still in a nascent stage in India though it has already made considerable progress in some other countries, especially where arable land is scarce. No doubt, bulky and weighty crops are not ideally suited for this system of farming but numerous high-value crops of smaller size can safely be grown in upright structures. Most vertical farming entrepreneurs produce stuff like lettuce, broccoli, medicinal and aromatic herbs, flowers and ornamental foliage; medium sized crops like tomato, brinjal and others; and fruits like strawberries.

Commercial cultivation of mushrooms in trays kept in shelves under protected environment is the most common example of vertical farming. Tissue culture, where plant seedlings are raised on synthetic medium in test tubes under artificial lights and atmosphere, is another common example of hi-tech vertical farming. Products free of diseases, pests and pesticide residues, grown in vertical farms, usually fetch premium prices because of their superior quality.

At present, vertical agriculture is confined largely to cities like Bengaluru, Hyderabad, Delhi and a few others where enterprising individuals begin it as a hobby but subsequently scale it up as commercial ventures. Many of them are using the well-known systems like hydroponics (where plants are grown in water fortified with needed plant nutrients) or aeroponics (where plant roots are merely sprayed with nutrient mixtures). In the case of potted plants, soil is generally replaced with mediums like perlite, coconut fibre, coco peat, crop straws or gravel.

However, there are some tricky aspects of vertical agriculture that are situation-specific and, therefore, have to be tackled on a case-by-case basis. Ensuring adequate light to plants is one of them. If sufficient sunlight is not available in the indoor units, artificial lighting needs to be arranged to facilitate normal plan growth. The LED bulbs and tubes, whose costs have dropped appreciably, usually come in handy for this purpose. Even light reflectors can be used to divert sunlight towards indoor plants.

Pollination is another issue that needs to be taken care of, especially in the case of cross-pollinated crops. In the absence of insect pollinators, especially in the indoor farms, pollination needs to be done manually which is costly and time-consuming. Some entrepreneurs now rear honeybees within the vertical farming units for this purpose. This also supplements income through the sale of honey and its high-priced byproducts like bee-wax, propolis and royal jelly.

One of the key reasons for meagre spread of vertical farming in India is the paucity of research and development (R&D) support. Hardly any institutional research is underway to refine vertical farming technology and bring down its cost. Such research is urgently needed to popularise this system of cultivation, maintains vertical farming proponent T. Janakiram, assistant director-general of the Indian Council of Agricultural Research. Both public and private sectors should consider setting up R&D facilities to promote vertical agriculture to tap its economic, environmental and other benefits.

Since transportation of huge quantities of farm products to ever-expanding urban centres is posing formidable problems, including traffic congestion and vehicular pollution, besides heavy freight costs, cities need to meet part of their requirement through local production. The government should, therefore, come up with policies to incentivise vertical farming.