In Kerala, where paddy cultivation is going out of favour because of labour problems and high costs, the novel System of Rice Intensification’ (SRI) has shown the potential to rehabilitate this crop.
This innovative technique ensures substantially higher productivity and lower input use. The SRI system has, in fact, proved its utility in many other regions as well, spanning Sikkim in the north-east to Tamil Nadu in the south.
The environment-friendly SRI method of growing rice involves transplanting relatively young paddy seedlings (eight to 10 days old instead of usual 20 days or more), along with the soil that contains their roots. The spacing between plants and rows is kept relatively wide at around 25 cms to provide room for the robust growth of both root and plant.
Plant nutrients are supplied largely through farm-yard manure, supplemented with need-based fertiliser applications. The most significant aspect of SRI is that the fields are not kept submerged under water all the time, as is usual in rice farming, but are allowed to remain just wet without flooding.
The success of SRI technology in most places where it has been tried in the past few years has led to its promotion in a big way by Krishi Vigyan Kendras (KVKs or agricultural science centres) and other farm research bodies under the Indian Council of Agricultural Research (ICAR). What makes the SRI method an instant hit with paddy growers is the saving of almost all key inputs (water, seed, fertilisers, pesticides and labour), and a perceptible spurt in crop productivity, which has, of late, tended to stagnate at many places.
The saving on water, which is rapidly turning scarce in most paddy-growing tracts, can be 30 to 40 per cent or more; that of costly seeds over 50 per cent. The reduction in the requirement of other inputs varies according to field conditions.
Higher crop yields in SRI fields are attributed to several factors. Since the seedlings are planted along with the soil in which these are growing, it helps the undisturbed roots to develop more profusely and enables it to tap more nutrients from the soil. This, in turn, facilitates a larger number of tillers (shoots) per root-system, vigorous plant growth and, more importantly, longer panicles (ear-heads) to accommodate more grain per plant.
Moreover, the fact that the seedlings are planted in wide-apart rows makes it easier for farmer to remove weed and other rogue plants that normally compete with the main crop for extracting nutrition from soil.
SRI fields also have a lower incidence of pests and diseases, mainly on account of lower humidity because the fields are not kept inundated. Overall crop yields have been found to surge by anywhere between 20 and 100 per cent over those obtained with normal cultivation practices.
The introduction of the SRI technique in different states has shown that it works well with both high-yielding varieties and local varieties of paddy. In east Sikkim, for instance, where farmers tend to grow only traditional varieties, such as Attey, Krishnabhog and Dudhetulsi, the new method enabled farmers to bag, on average, over 23 quintals of grain per hectare, against 19.6 quintals with conventional method, in kharif 2009-10. Farmers earned an average net return of around Rs 25,550 per hectare, more than double the production cost of Rs 10,950, according to sources in the KVK run by the ICAR Research Complex for the north-eastern hilly region, located in East Sikkim district.
In the Nellanad area of Thiruvananthapuram, where the SRI technology has been introduced by the local KVK in collaboration with the Coimbatore-based Tamil Nadu Agricultural University, farmers have reportedly reaped a paddy harvest of nearly 7 tonnes per hectare, against the state’s average crop productivity of 3 to 3.5 tonnes a hectare. This has spurred the state government to include the promotion of SRI in its overall agricultural development policy. Kerala’s example can surely be emulated elsewhere.
Similar encouraging results have been reported from Tamil Nadu’s key paddy belt in the Mettur dam command area where the uncertainty over the release of canal water from this dam has been posing problems for paddy growers. With the SRI technique, farmers can manage comfortably with whatever water is available.