System of Rice Intensification (SRI) as an alternate rice cultivation
methodology, developed in Madagascar 25 years ago, is gaining wider acceptance
in many countries including India. SRI method claims to greatly enhance water
productivity and grain yield. But there is lack of understanding of scientific
principles underlying and synergetic effects of the principles followed in SRI,
especially in Indian conditions. The present paper is intended to discuss about
significance and necessity of SRI along with performance of SRI at about 25
locations across the country for a period of four years. SRI was found to record 7-
20% higher grain yield over the traditional irrigated transplanted rice in different
agro-climatic situations of the country. SRI also recorded higher nutrient use
efficiency without depleting soil available nutrients as compared to conventional
transplanting"after two seasons of the study. The varieties having better tillering
ability as well as hybrids (KRH 2, HRI 126, PHB 71 and DRRH 2) were found
promising and recorded higher grain yield over the high-yielding varieties and
scented cultivars with moderate tillering. Root volume, dry mass and
dehydrogenase activity in soil enhanced by 7-25% (measure of microbial activity)
were found to be higher in SRI, compared with conventional method. There was
reduction in seed rate by 80%, nursery area also obviously, water requirement
by 29% and growth duration by 8-12 days, thereby enhancing water productivity
and per day productivity of rice cultivars in SRI, which also proved to be helpful
in producing more seed for faster seed multiplication and also quality seed for
higher productivity. Water saving alone should be a strong justification for the
adoption of SRI wherever water is not abundant. Ther~ is a need for further
enhancing the rice productivity in SRI by identifying suitable cultivars, modifying
practices to suit local agro-climatic conditions and understanding long term
synergic effects among different practices