The Hindu Business Line : System of Rice Intensification — Optimising production with fewer inputs

The System of Rice Intensification is an alternative to the traditional way of flooded rice cultivation and is showing promise in addressing the problems of water scarcity, high energy usage and environmental degradation.

The SRI method involves synergy of five important farm management techniques.

Vibhu Nayar
V. K. Ravichandran

The global community is faced with two challenges this millennium; one, the increased scarcity of water as seen from the droughts in Australia, parts of Asia and Europe and, two, the demand-supply mismatch in the availability of cereals such as rice, exacerbated by galloping prices. This is all the more critical in Asia, where 90 per cent of the world’s rice is grown and consumed.

World Development Indicators

The availability and efficient utilisation of fresh water resource is a major constraint on agricultural growth.

The Table illustrates the gap between the natural resource availability and utilisation levels in Asia. On the one hand, Asia is constrained by resource gap and, on the other, socio-cultural practices encourage water guzzling crops.

In India, rice alone accounts for 85 per cent of the water consumed in agriculture. It is estimated that by 2025, an area of 17mha under rice in Asia cultivation will face water scarcity, concomitant with global shortfall in production of over 200 million tonnes.

Some of these trends are manifesting in India as well, with stagnating yields and decreasing coverage of rice from 44.6 mha in 2000-01 to 41.9 mha in 2004-05. An IFPRI report also indicates that there has been a 21 per cent drop in cereal consumption over the last 25 years. Since rice is such a crucial crop for Asia, the challenge is to improve its water utilisation efficiency and productivity. System of Rice Intensification (SRI) is an emerging solution to these challenges. This method is an alternative to the traditional way of flooded rice cultivation and is showing promise in addressing the problems of water scarcity, high energy usage (40 per cent saving) and environmental degradation.

SRI is a synergy of five important management techniques. It encompasses careful transplanting of 14-day young seedlings at wider spacing (23x23cm) on a square with only one seedling per hill, water management that keeps the soil moist but not continuously flooded — alternate wetting and drying, mechanical weeding through rotary weeder before canopy closure and higher use of organic compost as fertiliser.

Promising results

This SRI technique is also being promoted in Tamil Nadu under the TN-IAMWARM Project. A multi-disciplinary project of the Government of Tamil Nadu, assisted by the World Bank, TN-IAMWARM aims to improve water productivity and income of the farmers.

The SRI mission is showing promising results for all rice varieties (local or improved) and hybrids. Conventional wisdom suggests that higher yields in rice come with high investments on seed, irrigation, high doses of fertilisers and pesticides. Contrary to this view, the SRI produces higher yields (40-80 per cent) with less seed (85 per cent) and economised water use (32 per cent saving).

Increased productivity

The introduction of SRI over 5,000 ha in the very first year (with plans for two lakhs ha) has brought visible changes in the agrarian context. Studies carried out by TNAU in 100 locations have indicated 32 per cent water savings, which is corroborated by farmers such as Mrs Vijaylakshmi of Villupuram, who could increase her cropped area by 40 per cent with the same quantity of water.

Mr K. Shanmugam raised SRI paddy in Mahibalanpatti of Manimuthar sub-basin in the dry Sivaganga district, harvested 8,750 kg/ha compared to 4,750 kg/ha in the previous year by using ADT 39 variety (84 per cent increase). Around 49 per cent yield increase was also observed by Mr C. Ravi of Pallathathanur of Salem district Upper Vellar sub-basin) where the availability of water is always assured. He realised a yield of 9,633 kg/ha using the SRI method compared to 6,483 kg/ha.

In all these instances, the seed rate was just 8 kg/ha against the conventional practice of 30-60 kg/ha and fertiliser and pesticides application was much more judicious. Field studies indicate that the resultant decrease in inputs such as seed and chemicals, combined with improved yields, leads to an average increase in net income by Rs 12,719/ha, a 100 per cent increase over the conventional cultivation method.

It is estimated that if the SRI is adopted even on just 25 per cent the irrigated rice area in India (5.3 mha), there would be a saving of paddy seed worth Rs 500 crore. The increase in production because of increased yield (40 per cent) and better water productivity (32 per cent water saving) bringing more area under irrigated rice cultivation is estimated to be about five million tonnes — enough foodgrains for about four million families for a year under the public distribution system.

The expected increase in net income would be about Rs 6,741 crore. Assuming that 50 per cent of the irrigation is groundwater-based, SRI would save energy (40 per cent) equal to 632.61 million kWh which means a savings of Rs 253 crore, as well as 10,000 million cu.m of irreplaceable groundwater for future generations.

This is apart from unaccounted benefits such as health, nutrition and general improvement in the rural economy.

Change in mindset

Up-scaling the evident benefits of SRI across the country would require a change in the mindset of farmers, who need exposure to best practices, technology transfer through cluster approach, skill upgradation of labour, adequate and timely availability of simple mechanical implements such as rolling markers and rotary weeders and, most important, regulated water supply.

The TN-IAMWARM project has definitely made a significant contribution in making farmers realise that paddy cultivation through SRI is the way forward to enhance water productivity, improve farm income and achieve better livelihood. It is now opportune for the rest of Asia to examine, experiment and formally adapt it.

(The author is an IAS officer and the views are personal. E-mail: vibhunayar@yahoo.com)