SRI – to break the yield plateau in irrigated rice with
effective input management
R. Rajendra=
n,
V. Jayabal, R. Kavimani , S. Na=
sir
Ahmed,
V. Muralidharan and V. Balasubramanian*
Tamil Nadu Rice Rese=
arch
Institute, Aduthurai – 612 101, TN
*
Formerly Scientist, International Rice Research Institute, Philippines
Rice is the staple food for about 60% of Asian
population and more than 75% of=
the
annual rice supply comes from irrigated rice area. From 1990 onwards, rice
yields remain stagnant and even started declining due to complex production
factors. The future global rice
requirement could be met only by enhancing irrigated rice productivity. The
recent management approach introduced in India as “System of Rice
Intensification” (SRI) enthused the rice researchers, extension worke=
rs
and attracted the farmers for its significant contribution in boosting rice
productivity and profit.
Modified rice mat nursery developed by Tamil Nadu Agricultural University, Co=
imbatore popularized in the Cauvery
Delta, reduced 80% of seed rate besides saving 35% lab=
our
cost and 50% water use. The
management practices were suitably modified in Tamil Nadu,
according to the needs of the local situation and practiced as “modif=
ied
SRI”. Although there was 40-50% water saving in the main field report=
ed
under the modified SRI approach, there were reports of yield disadvantage in
few locations besides the practical filed problems in adopting the controll=
ed
irrigation in the Cauvery Delta as a whole. Ric=
e crop
managed with modified SRI method and evaluated through the on-station and
on-farm experiments at the Cauvery Delta, Tamil=
Nadu during 2003-06 had shown enhanced productivity r=
anging
from 20 to 40% in most of the rice varieties as compared to the existing cr=
op
management practices. These encouraging results revealed the scope for boos=
ting
the productivity of existing rice cultivars by making appropriate changes in
the existing management practices. Experiments conducted in two research
stations in Cauvery Delta during 2003-2005 indi=
cated
that site-specific nutrient management when adopted with improved crop
management practices as suggested in the modified SRI method enhanced the
agronomic efficiency of nitrogen (26 kg grain yield increase/kg N applied) =
as
compared to the conventional management practices (21 kg grain yield
increase/kg N applied). On-farm demonstrations conducted during 2003-04 in =
the Cauvery and Tamirabarani =
river
basins popularized the modified SRI approach among the farmers in Tamil Nadu. The results have clearly indicated the enhanced=
rice
productivity in both marginal (by farmer capacity and soil fertility) and
well-managed farms. The farmers themselves have modified few practices while
adopting it in their own farms. The
real constraints prevailing at farm level need to be studied for
simplification; especially in the production of healthy seedl=
ings
within 15 DAS, adoption of square planting and mechanical weeding. The
researchers and extension personnel should work together to fine tune the
management practices for farmer friendly, faster adoption.
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