A superb substitute for soil

Soil scientists have shown that using coco pith laced with nutrient-rich solutions in urban gardening is cost-effective and safe

Researchers assessing the nutrient quality of coco pith at the soil testing laboratory of IIHR.

Replete with the concept of urban farming for over a decade, urban jungles like Bengaluru are now at the threshold of experimenting with new gardening trends, ushering in urban green-revolution. The growing need for nutritious food free from toxins had spurred the interest of many dwellers of multi-storeyed buildings in balcony and terrace farming.

However, the possibilities of structural damages to the building due to heavy loads of earthen and concrete pots, leaking roofs and dusty balconies riddled with pests and termites prevented many from practising urban farming.

Allaying fears of urbanites and instilling confidence in them to grow their own food, scientists at the Indian Institute of Horticultural Research (IIHR), Hesaraghatta have successfully demonstrated the techniques of soilless cultivation.

When nutrient-rich soil (red soil) is seen as prized possession in the urban environs, the organic method of raising plants using only the coco pith laced with nutrient-rich solutions has caught the attention of many.

Adopting the techniques of soilless cultivation, several gardeners have successfully cultivated their daily dose of vegetables and greens at a much cheaper price than what it used to be with the use of soil.

“For those who worry about structural damages to their balconies and terraces due to heavy pots... the coco pith is only one-tenth of the weight of the soil. One hundred kg of coco pith is equal to 1,000 kg of soil on your balcony or terrace. Further, it has more significance when it comes to nutrients,” claims Dr M R Dinesh, Director, IIHR.

Takers many

The IIHR’s workshops and demonstrations using the latest techniques of urban farming has been a hit among the urbanites. “Over a year since the introduction of soil-less cultivation techniques, more than 500 people have taken to the idea of balcony and terrace farming without using even a gram of soil,” he says.

For those who argue that a medium like this is sufficient to grow only ornamental plants, scientists have demonstrated cultivation of vegetables and fruits that are consumed every day.

A terrace with an area of 1,200 sq ft (30x40 dimension site) can accommodate about 70 huge bags of coco pith, supporting cultivation of multiple vegetables without harming the structure.

D Kalaivanan, Scientist (soil science) at IIHR says, “Finding a well-drained, pathogen-free soil is almost next to impossible. The varying levels of alkalinity, possible presence of pests, and toxic chemicals in soil always affect the production, dampening people’s spirit. Replacing soil with coco pith is also a solution to overcome the acute shortage of water. Even though the top layer appears to be dry, the bottom of the pith always has enough moisture to support the plant.”

Arka-fermented coco pith, enriched with Arka microbial consortium, developed in 2015, is being used as potential substrate for soilless cultivation of vegetables among urban gardeners.

“At a time when each bag of soil costs Rs 100 to Rs 150, one could pursue their passion with Rs 10 to Rs 20 by using coco pith. Each plant would require about 4 to 5 kg of coco pith, and lasts for two to three years provided you regularly water it with the mixture of nutrient-rich solution,” Says Dr Jagadish, yet another scientist at IIHR.

Tomato, chilli, brinjal, beans, gourd varieties, leafy vegetables can be grown using soilless cultivation. Switching over to the soilless cultivation, Veenashree R, a teacher and a passionate urban farmer in Rajarajeshwari Nagar, has not only cut down on the bulky pots on her terrace and balcony, but also saved on other expenses including de-weeding, re-potting. “I have been using pots made of cement bags filled with coco pith to grow vegetables ranging from leafy vegetables like palak to veggies like capsicum. The coco pith medium is convenient for vertical gardening as well. As the pith is free from parasites, there is no fear of soil-borne diseases and termites to the plants. It also regulates the growth of weeds. The used coco pith can again be mixed with the fresh one as a nutrient-rich compost,” she says.