Evaluation of principles of SRI and their role in enhancing the productivity of rice

Evaluation of principles of SRI and their role in enhancing the productivity of rice

R.Mahender Kumar*

V.R.Babu, L.V.= SubbaRao, K.Surekha, P.C.Latha, Ch.Padmavathi, M.S.S.Prasad, P.Muthuraman, J.S.Prasad,= P.R,Rao, S.P.Singh, S.V.Subbaiah<= /span> B.C.Viraktamath (DRR), O.P.Rupel= a, M.V.R. Murhty , Blummel (ICRISAT) V.Goud (WWF) and A.Ravindra (WASSAN)

* Directorate of Rice Research,ICRISAT,WWFand WA= ASAN

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The System of Rice Intensification (SRI ) that evolved in late 1980s’ in Madagascar permits resource lim= ited farmers to realize yield of up to 15 t of paddy/ha on infertile soils, with greatly reduced rates of irrigation and without external inputs (Willem A. Stoop et al., 2002). T= his method was not known outside Madagascar till 1997. At present , about 1 lakh farmers world wide (China, Indonasia, Combodia, India, Thailand, Bangaladesh= , Srilanka and Cuba) are practicing SRI meth= od.

= SRI grew out of insights gained by Fr. Henri de Laulani&ea= cute;, SJ, from three decades of work with rice and rice-growing farmers in Madagascar. He sought to learn how to provide the best possible growing environment for ri= ce plants. Although SRI practices were crystallized in 1983, their spread was = slow for the next 15 years. They were first tried outside of Madagascar in 1999, at Nanjing A= gricultural University in China, and then by the Agency for Agricult= ural Research and Development in Indonesia. Since 2000, the evaluation and dissemination of SRI has started in more tha= n 15 countries, usually with good results, and sometimes with spectacular result= s.

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   &nb= sp;        The green revolution phase in India was characterized by the wide spread adoption of varieties, boosting productivity and resulting in a steady growth of food and non-food crops. T= he first post-green revolution phase saw continued growth in returns to land through intensified use of chemical and labour = inputs per hectare. The second phase began when inputs use was high, and further grains in productivity were largely dependent on increased efficiency of in= put use. The objective of SRI is to achieve higher productivity from the factors of rice production land, labor, capital and wa= ter. Increase in productivity should be achieved in ways that benefit both farme= rs and consumers, especially poorer ones, and should be environmentally friend= ly to support equity and sustainability. The exact yields obtained with the methods will vary considerably, since yields depend on the skill with which the practices = are used as well as upon the soil and other growing conditions for the rice. SRI has great potential and could be= the harbinger of another green revolution.

It should be possible to id= entify the most suitable areas for SRI practice, based on climate, soil, economic = and other considerations. There is also a need to analyze soil status and quali= ty in chemical, physical and biological term and then collective agronomic and economic data as well as soil data over time, to monitor and understand long term effects of SRI.

The advent of hybrids in ri= ce is one of the options to meet the food supplies for growing population to some extent. To popularize the hyb= rid technology , the seed availability and reduction in co= st of seed plays an important role. SRI method promises to reduce the seed requirement by 6 times and seems to be viable technology. Hence there is a = need for evaluation of SRI methods for hybrids and fine tuning of the technology. Further it is essential to find out plant physiological and bio-ecological factors associated with agronomic practices that could expla= in the extraordinary yields in terms of synergies resulting from the judicious management of the major crop production factors: time, space, water, plant nutrients and labour.

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All the varieties used so far have been given higher yields with SRI practices, though not surprisingly, some varieties responded bette= r than others e.g., producing more tillers or giving better grain filling. It= was observed that 120-140 day varieties respond most productively, but more evaluation is needed on this (Norman Uphoff and= Erick Fernandes, 2002) in different parts of the coun= try as per their local choice and availability. Irrigated agriculture is the bigge= st consumer of world-wide, but declining water resources and increased competi= tion from other users – domestic, industrial and environmental purposes may result in less water being available. In Asia, particularly in India, = rice is the biggest beneficiary of irrigation and ways must be sought to “gorw more rice with less water”. SRI seems to r= educe the water requirement for rice enhancing water productivity to a greater extent. Analyzing the trends and development of rice intensification in the would, particularly in India, we see the conditions = that we have to keep pace with. Th= ere are major emerging global issues concerning water scarcity and environmental degradation. There are concer= ns about maintaining and improving land productivity as a key factor for succe= ss of any intensification programme for rice over the long run. These problems can be addressed through SRI evaluation, and fine tuning to suit local conditions and its implementation throughout the country as it makes fewer demands on water and aims to build= up soil quality and health

Sheehy= et al., (2004) investigate= d the general potency of the SRI conducted in China comparing conventional and SRI management systems and also used the theoretical model to predict maximum yi= elds and compared those with reported yields for various locations and indicated that SRI has no inherent advantage over the conventional system and that the original reports of extraordinary high yields are likely to be the conseque= nce of error. Dobermann (2004) hypothesized that the benefits of SRI over conventional rice management are likely to be small in well managed rice crops grown on fertile rice soils with no-specific constraints. Satyanarayana (2004) stressed the need for popularization= and intensification of research efforts on SRI= in different farming situation. SRI is still evolving and emphasized the<= /span> need of the scientific community to collaborate in refining the technology = and working out scientific reasons for reported higher yields with the technolo= gy.

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SRI differs fro= m the normal flooded rice in four ways: a) transplantation of 8-10 day old seedli= ngs, b) wider spacing (25 x 25 cm), c) no flooding except fo= r a short period after transplanting, but moist soil surface, d) use of more compost and less chemical fertilizers. SRI is advantageous over cont= rol for being high yielding, water saving, seed savi= ng and for its low dependence on chemical fertilizers (Uphoff= 2004).

Salient findings of the trials conducted at DRR (DRR)<= /span>

·      =             &nb= sp;            = Initial experiments of SRI method vs Normal transplanting were carried out at DRR by ta= king seven cultivars (two hybrids - PHB-71, DRRH-1, four high yielding varieties – Jaya, Rasi, Krishn= ahamsa, Tulasi and a scented variety – Pusa Basmati) in clay soils during rabi 2003 – 04 season.SRI method gave 16.6% hi= gher grain yield over normal transplanting.&nbs= p; There was wide variability among cultivars for different methods of = SRI and normal transplanting. SRI method gave nearly 46 – 48% higher yield in hybrids (PHB-71, DRRH-1),= 5.2 to 17 % in high yielding varieties (Tulasi, Rasi, Krishna hamsa and J= aya) while negative results of decrease in yield obtained with Pusa basmati (-35 %) due to its shy tillering charac= ter under wider spacing (Kumar et al,2004) .&n= bsp; Further Hybrids tested under SRI method performed better as compared conventional method across the country under AICRIP trials.

·      =             &nb= sp;            = Preliminary investigations during kharif 2004, revealed that response of s= ome varieties was good for SRI practices resulting in more tillers and increased yield. Stem borer damage was found high in some varieties. Incidence of leaf mite was severe in Swarna variety grown under SRI method. However plant resistance to pests and diseases was reported high in SRI method that needs further study. The wide spacing in SRI was mainly responsible for the low damage by the insect pests, particularly brown and green leafhoppers. Plants grown by SRI method were found less attractive to pests in farmers field in Sri Lanka. They also observed the advantage of maintaining biodiversity in their fields resulting in an increase in predator populations, thus avoiding the usage of biocides (Gamini P Batuwit= age, 2002)

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In order to compare SRI met= hod with conventional flooded rice and document agronomic, physiology, soil microbiology parameters, soil health build up a replicated long term field exper= iment was initiated during post rainy se= ason 2005-06 in collaboration with ICRISAT, WWF, and WASSAN. The salient findings of the study are:

= -&nb= sp;            =          Yield levels are generally low and it was expected due to several factors includi= ng delayed sowing and initial soil management .

= -&nb= sp;            =          On the basis of means of the 3-cultivars, there were signi= ficant yield differences between S= RI (3.32 t/ha) and conventional (3.45 t/ha). Eco-SRI was however, the lowest yielding treatment by about (1.65 t/ha) as expected due to first season of= the experiment. We hope that it will improve in subsequent years. It may be not= ed that it also serves as an indicator of the native fertility of the soil.

= -&nb= sp;            =          On the basis of means of the three treatments, cultivar DRRH2 yielded best (4.07t/ha) over MTU 1010 ( 2.67 t/ha) and Shanthi the lowest (1.69 t/ha).

= -&nb= sp;            =          Treatment and cultivar interactions were non significant for grain and straw yield (a= t 5% level) .

-       &nb= sp;            = Overall, there were yield of the methods of crop establishment (SRI and conventional) were similar and however, there was significant saving in water (22 % in SRI) while SRI eco reduced the water requirement by 39%

-       &nb= sp;            = There were no significant differences in Avilable NPK content of initial and harvest of the crop from both the depths of the soil= ( 0-15 and 15- 30 cm).

-       &nb= sp;            = There was significant higher Chlorphyll values ( SPAD v= alues ) in SRI as compared to conventional method clearly indication better nutri= ent uptake in the SRI method.

-       &nb= sp;            = The digestibility of the straw from = SRI –Eco was higher as compared to normal rice.

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The impact analysis of SRI farmers in four distric= ts of A.P along with WASSAN clearly indicated the following findings:<= /span>

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-       &nb= sp;            = 90% the farmers expressed the superiority of SRI to an extent of 15 – 20%= in terms of higher grain yield. The yield variability is due to adoption of the SRI principles. 5 – 6% farmers expressed that equal/on par yields are obtained in SRI as compared to NTP.

-       &nb= sp;            = Time of the sowing has major role in (early, optimum or late= ) sowing has the significant effect on yield.

-       &nb= sp;            = All the farmers expressed that there was saving inputs such as labour, water fertilizers.

-       &nb= sp;            = When practiced for the first time, the labour requir= ement increased by 10 – 15 especially for transplanting. However, the labour can practice the technique very fast after gai= ning experience.

-       &nb= sp;            = All the farmers are in the opinion to popularize the technique in a wide-scale = as it saves water.

-       &nb= sp;            = Weeds are main problem and use weeders is the difficult for adoption of techniques.

-       &nb= sp;            = SRI method practiced at DRR could save irrigation water up to 30 %, cost of weed control to an extent of 40 % and seed cost to 60 %, hence highly suitable to hybrids whose seed cost is 6 times higher than HYVs ( cost of hybrid seed Rs 60 /kg, HYV seed Rs 10 /kg and Cost of man day of 8 hours Rs 50 = /man and Woman day of 8 hours Rs 30/day )

-       &nb= sp;            = SRI method offers great potential to reduce water consumption with increase in yield and productivity with reduction in the cost of cultivation. Another important change is growing rice in organic way. The Robust root system needs sufficient and balanced nutrition. Organic manure is required in ample quantities to meet the demand. Dependency on external inputs will drastically reduce and the demand for green manures and locally available organic wastes will rise . Nevertheless, SRI method is passing through a testing time now, the&nb= sp; growing fascination to adopt this methods by farmers notwithstanding= .

REFERENCES:

= 1.      = DRR(Directorate of Rice Research)2005, Annual Report 2004-05, Directorate of Rice Research RajendraNagar, Hyderabad – 500 030

= 2.      = DRR(Directorate of Rice Research)2005, Progress Report 2004, Vol 3. Agronomy , Soil Science and Physiology , All India Co-ordinated Rice Improvement Programme (ICAR) Diretorate of Rice Research Raje= ndraNagar, Hyderabad – 500 030

= 3.      = Satyanarayana . A (2004). System of rice intensification (SRI) Higher rice yields with less cost= s and less water.ANGRAU, Raj= endranagar, Hyderabad-pp11.

= 4.      = Sheehy= J.E. S. Peng, A. Dobermann, P.L. Mitchell, A. Ferrez Jianchang Yang, Yingbin Zou, Xuhua Zhong, Jiarliang Huang. (2004). Fantastic yields in the sys= tem of rice intensification: Fault or fallacy?&nb= sp; Field Crops Research 88 : 1 – 8

= 5.      = Stoop, W.A, Uphoff. N and Kassam, A, Agric. Sy= st. 71, 249-274.

= 6.      = Thiaya= garajan,T.M. (2002). Experiments with a modified system = of rice intensification in India. Assessments of the System of Rice Intensification (SRI)= . In proceedings of an International Conference on the System of Rice Intensification . Land scape Beach Hotel, Sanya ,= China. April 1-4, 2002

= 7.      = Uphoff= , N ,20= 02. Changes and evolution of in SRI methods. In ; Proceedings of International Conference on Assessments of = SRI, Sanya, China, 1-4 April 2002, Cornell University, Ith= aca, New York, 00. 8-14

= 8.      = Uphoff= . N and Erick Fernandes. (2002). System of Rice Intensification gains momentum. LEISA India September, 2002 pp 22 &= #8211; 27

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