Evaluation of System of Rice Intensification (SRI)

Evaluation of System of Rice Intensification (SRI)

under<= span style=3D'font-size:11.0pt;font-family:Garamond'> All India Coordinated Rice Improv= ement Project

B.C. Viraktamath

Directorate of Rice Researc= h, Rajendranagar, Hyderabad –500 030, AP

&= nbsp; Rice is one of the most important cereals that holds = the key for food security. It is the staple food for more than 70 per cent of people living in Asia= where more than 90 per cent= of it is produced and consumed. In = India, = rice is presently grown in an area of 42.5 m. ha.&= nbsp; with a production of about 87.5 m. t. At the current rate of population growth, the country has to produce about 130 m. t. of rice by 2025 to feed = the ever growing population. Meet= ing the targeted demands of rice is a challenging task for the policy makers, researcher and all other stakeholders.&nbs= p; The problem is still confounded as the targeted increase has to be m= et in the background of declining resource base especially the land, water and= labour and increasing environmental concerns.

&nb= sp; Increasing water scarcity is becoming a real threat for rice cultivation. About 80 percent of fresh water is= being used for agriculture and out of this more than 50 percent is consumed by the rice crop alone. The annual p= er capita availability of water is declining at a faster rate (1951 - 5177 CM;= 2001 – 1869 CM; 2025 – 1341 CM) and there will be 10-15% reduction in the water available for irrigation by 2025. This drastic reduction will = have far reaching consequences on rice production and productivity. Many governments are trying to red= uce the area under rice to save water and crop diversification is advocated. The prevailing precautious situati= on has given us a wake up call to develop and popularize innovative water saving technologies to “produce more rice crop from every drop”. It is now evident that rice = crop cannot have the luxury of water that it had in the past due to acute water shortages. There are some opt= ions such as zero tillage, direct seeding, aerobic rice and the System of Rice Intensification (SRI) which can help to save water and enhance water productivity in rice cultivation. However, the former methods lead to yield penalty, while SRI has the potential to enhance yield and economize the water use. The System of Rice Intensification developed in Madagasuar in late 80’s is s= lowly spreading to other countries. In India this system was directly taken to the farmer’s fields without much research backing. Many claims= and counter claims have been made about the feasibility of the system. Therefore, Directorate of Rice Res= earch conducted a preliminary trial during Rabi 2003 and organized the multilocation trials at 21 locations spread across the country during Kharif seasons of 2004 and 2005. The result revealed interesting facts which are briefly presented in this paper.

&nb= sp; A preliminary trial on SRI was conducted at DRR during Rabi 2003. This trail had 7 varieties (2 hybr= ids – PHB-71 and DRRH-1 and five varieties – R= asi, Tulsi, Krishna Hamsa, Jaya and Pusa Basmati) and 4 methods of crop establi= shment (S-1 – Standard transplanting; S-2 - SRI with 12 days old seedlings; S-3 - SRI with 25 days old seedlings and S-4 – Normal transplanting w= ith 25x25 spacing) were compared. The results indicated that SRI resulted in 16.6% yield advantage over normal transplanting. The varieties = responded differentially for SRI method of cultivation. Hybrids performed exceedingly well= under SRI (46-47% yield advantage). Pusa Basmati variety did not do well under SRI (35% y= ield reduction). SRI with older seedlings (25d) and normal planting with wider spacing did not show any advantage over SRI thus indicating the importance of younger seedlings for planting. <= /p>

&nb= sp; Multilocation trials on SRI were conducted at 21 loca= tions viz., ARI Rajendranagar, A= duthurai, Almora, Arundhatinagar, Chiplima, = Coimbatore, Jagdalpur, Karimgunj, Karjat, Kapurthala, Malan Mandya, Nawagam, Patna, Pantnagar, Pondicherry, Ranchi, Sabour, Siriguppa, Titabar, Umiam and Varanasi both during Kharif 2004 and 2005. During 2004, the trial was conduct= ed with 3 varieties (Krishna Hamsa, KRH-2 and the = local) while during 2005, the trials had only the local variety.

&nb= sp; In these trials, four methods of crop establishment were evaluated.

S-1	:	Standard transplanting (25 d old seedlings, close spacing, inorganic fertilizers, standing water)
S-2	:	System of Rice Intensification (8-12 d old seedlings, planting with soil, organic manures, wider spacing 25x25 cm, weeding with cono weeder, alternate wetting and drying)
S-3	:	Integrated Crop Management (ICM)<= /p> (14-15 d old seedlings, close planting, FYM +₌inorganic fertilizers, LCC based application of N, AWD)
S-4	:	Direct Seeding with drum seeder

&nb= sp; = Results obtained during both the years were more or less similar. During 2004, the differences betwe= en the treatments were not significant at 4 locations (Karimg= unj, Pantnagar, Pondicherry and Umiam). The interaction between the varieties and the method of establishments were significant at 5 locations. SRI method was distinctly superior= to all other methods at 3 locations (ARI Rajendranagar, Patna and Almora) At 11 locations (Aduthurai, Arundhatinagar, Jagdalpur<= /span>, Karjat, Mandya, Ranchi, Siriguppa, Titabar Rajendranagar, Patna and Almora) SRI gav= e higher yield (7-42%)as compared to normal transplanting with a mean advantage of a= bout 12% ICM was better than SRI at C= oimbatore and Aduthurai.= Normal transplanting was found to be superior to SRI at Kapurthala and Malan. The hybrid KRH-2 performed better than= the varieties under SRI method. I= CM and SRI were on par at Mandya, Ranchi, Karjat and Jagdalpur. Increased yield in SRI was attributed mainly to increased panicle number and panicle weight per unit area. Performance of SRI was = better in clay loam soils&nbs= p; than in sandy l= oam soils. Response to SRI was be= tter in acidic soils (pH 5.4 – 6.5) as compared to alkaline soils (pH 7.5 = to 8.1).

&nb= sp; During 2005 season, the yields under SRI were higher than in normal transplanting = at 10 locations (ARI Rajendranagar, Comibatore, Aduthurai, Siriguppa, Mandya, Jagdalpur, Varanasi, Rewa, Patna, Karjat). At four locations viz., Karaikal, Kapurthala, Pusa, and Malan, normal transplanting was be= tter than SRI. SRI and ICM were on= par at 7 locations where as SRI was found to be better than ICM at Rewa and Aduthurai. In general performance of SR= I was better in Southern and Central India. Again, performance of SRI was bett= er in acidic soils, as observed in 2004.

&nb= sp; Systematic evaluation of SRI in multilocation trials revea= led that the response is location specific as only in half of the locations (10= -11 out of 21) SRI was found to register higher yields than normal transplanting. SRI and ICM we= re comparable at few locations. = The results indicated that hybrids do well under the SRI method. This is the positive point for the spread of hybrid rice as there is a saving of Rs.1500/ha in the seed cost (5 = kg instead of 15 kg/ha)besides saving of water to an extent of 30-50%. At Kapurthala= and Malan, the yields under normal transplantin= g were higher than SRI in both the years. Response of SRI was better in acidic and clay loam soils. Further research is needed to refi= ne the location specific SRI technology and to identify the genotype suited to SRI= so as to ge= t higher yields with less and less water.