BACKGROUND
System of Rice Intensification was first developed in Madagascar during the `80s. It was not known outside Madagascar till about 1997. The last decade has witnessed its spread and adoption amongst the agriculture community in several countries across the globe. The potential benefits of SRI are being tested in predominantly rice growing countries like India, China, Thailand, Indonesia, Bangladesh and Sri Lanka. SRI methodology uses fewer inputs than conventional paddy cultivation. It uses less seed, water, chemical fertilizers and pesticides but uses more organic manures. It has been established that with SRI method of cultivating paddy, rice yields have dramatically increased. There has been marked increase in root volume, profuse tillering with bigger panicles, and well-filled spikelets with higher grain-weight.
CENTRAL PRINCIPLES
The synthesis of SRI has proceeded empirically, but the central principles for getting best results are: »rice field soils should be kept moist rather than continuously saturated, minimizing anaerobic conditions, as this improves root growth and supports the growth and diversity of aerobic soil organisms; »rice plants should be spaced optimally wide to permit more growth of roots and canopy and to keep all leaves photosynthetically active; and »rice seedlings should be transplanted when young, less than 15 days old with just two leaves, quickly, shallow and carefully, to avoid trauma to roots and to minimize transplant shock.
ADVANTAGES AND DISADVANTAGES OF SRI
Advantages
» Saving on seeds, as the seed requirement is less» Saving of water, as the water requirement is less» Withstands short gaps in water availability» Saving on chemical fertilizers, pesticides» More healthy and tasty rice due to organic farming practices» Higher yields due to profuse tillering, increased panicle length and grain weight» Easy and effective seed multiplication, as a small quantity is required as seed
Disadvantages
» Higher labour costs in the initial years
» Difficulties in acquiring the necessary skills