A combination of charred and uncharred rice husk in 1:1 proportion along with dried cow dung and coir pith compost has been successfully experimented as a soil-less medium for growing vegetables on terraces and in kitchen gardens, the interest in which appears to have boomed because of the restrictions imposed on people’s movement to contain the spread of COVID-19 pandemic.
A.A. John Sherry, Assistant Director, Agriculture Department, said he had been experimenting with the soil-less medium for three seasons and that he had met with considerable success.
According to his initial understanding, the chemical make-up of rice husk, which has ingredients like silica, ash, carbon, calcium and magnesium, is the key reason for the success. These contents in rice husk provide a certain sturdiness to plants. Besides, there is considerably more air circulation in a growbag with husk in place as a major component. This is a condition which helps root growth.
It has also been observed that pest attack in plants grown in the medium is less. Another advantage is that growbags filled with the medium is significantly lower. Conventional growbags with soil as medium weigh around 10 kg to 12 kg whereas the weight of growbags filled with rice husk-dominated medium is around three kg. This is an advantage when growbags are on house terraces.
Mr. Sherry said that the culture of growing vegetables in growbags had now spread to rural areas too though it was initially an innovation to help those in the urban areas to use any little space available to grow vegetables they wanted. One of the key disadvantages has been that it is difficult to get good quality top soil and the new medium could be an answer to the problem. While the use of soil can be avoided, rice husk that is dumped as waste by milling units can be utilised profitably, he added.