Compared to nearly a decade back today in paddy growing the systematic rice intensification method called SRI cultivation is universally accepted as a proven method to increase rice yield.
Unlike the conventional method, SRI is based on some basic principles like developing a nursery rich in soil nutrients and does not require flooding, early planting of single seedlings in the main field using nylon ropes as markers and planting with a wider spacing between each seedlings.
By doing so water requirement is considerably halved than what is required in conventional planting. Also seed requirement is also low, about one tenth for an acre.
Before sowing in the nursery, farmers can treat the seeds with pseudomonas at 10gms/kg seed or 200gms azophos biofertilizer for three kg of seeds or rice gruel at two litres for every two kg of seeds.
It is advisable to cover the nursery beds using locally available mulching materials like paddy straw after sowing. After three to five days remove the straw during evening time and sprinkle water. Irrigation must be done for 14 to 15 days in the nursery. While transplanting in the main field square planting at a spacing of 25x25 cm is advised because it ensures optimum space for the crops to efficiently utilize resources. Besides it eases operation of cono weeder to remove the weeds.
The small metallic wheels of the weeder uproot weeds if any and mix it along with the soil thereby giving the main crop time to establish well in the soil before the weeds start growing again.
Use of cono weeder is one of the important steps in SRI. It must be used at 10 days’ intervals from the transplanting day from nursery to main field.
Also irrigate to a depth of 2.5 cm (after hairline crack formation up to panicle initiation and after disappearance of residual water in the fields) as continuous flooding in the main fields during the early stages will diminish the size and health of root systems, making them less tolerant to water stress later. Hence, alternate wetting and drying is advocated.
(Mr. E. Jegadeesan, Junior research fellow, Oil seeds research stations, Tamil Nadu Agriculture University, Tindivanam, mobile: 94443 12958.)