MIME-Version: 1.0 Content-Location: file:///C:/CEF410B8/Lead8.htm Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="us-ascii" Modified SRI with hybrid rice

Modified SRI = with hybrid rice

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B.N. Singh,

Direct or of Research, BAU, Ranchi

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System of Rice Intensificat= ion (SRI) technique was developed in Madagascar= , Africa in mid 1980’s and it has now spread in over 20 countries of the Asia, Africa and Latin America (Uphoff, 2006). This technology is suited for both irr= igated and rainfed lowlands with limited water supply.= In future when irrigation water availability will be reduced, this technique s= hows the hope to increase rice productivity for lowlands.

 

So far the SRI system has b= een evaluated and practiced with self pollinated rice varieties. On-station research has given the mixed results of advantage with SRI System, but on-f= arm results have shown better yields over traditional system in many countries = and in Southern Indian states of Andhra Pradesh, Karnataka and Tamil Nadu.

 

Technological Components of SRI

 

-&nb= sp;            =          SRI has five components

-&nb= sp;            =          Use of organic manures

-&nb= sp;            =          Transplanting 10 days old single seedling at wider spacing

-&nb= sp;            =          Alternate wetting and drying of field

-&nb= sp;            =          Frequent hoeing and

-&nb= sp;            =          No standing water till P.I. Stage

 

Organic manures like FYM, compost, vermi compost, or cakes (Karanj, neem, castor etc) @ 5 tons ha-1 are = used in soil a fortnight before transplanting and land is ploughed with cultivat= or. Seedlings can be raised by both as raised bed under dry bed method or as wet method with sprouted seed in paddled soil. Seedling can also be raised by <= span class=3DSpellE>Dapog method on plastic sheet or in wooden frame beds= of one meter square with filled soil, sand and fertilizer mixture.<= /span>

 

Ten days old seedlings are transplanted in well puddled and leveled field = at 25 x 25 cm distance. Puddling should be done a day earlier so that soil is settled. Make small allies after 10 meter for drain= age. Seedlings are uprooted with soil from nursery bed and taken to the field in trays. Roots are not washed and one seedling per hill is transplanted. Once= the seedlings are established light irrigation is given after a day or two depending on the soil condition.

 

Gap filling should be done = with fresh seedlings from seed bed within 3 to 4 days after transplanting (DAT). Rotary weeder is used in between rows, first at= 15 DAT and then at 10 days interval. Rotary weeder= is run in criss cross manner till panide initiation stage. Depending on the total crop duration 5 to 6 operations are carried out in a crop. In a variety like Swarna, Sambh= a mahsuri or PA 6444 hybrid, which matures in 145= days, last rotary weeder operation stops at 85 days, = and variety of 130 days duration, it stops at 70 days. Weeds near the hill or p= lants are removed by hand weeding. Weeds are incorporated in soil through weeder use and it increases the organic biomass in so= il. Only during weeder operation, little water is k= ept in field through irrigation or rain, and later it is drained. Alternate wetting (anaerobic) and drying (aerobic) conditions of field and facilitates the ro= ot growth and increased microbial activity of organic matter.

 

Advantages

 

-&nb= sp;            =          Reduced seed rate and seed = cost: In SRI method as single se= edling is used, the seed rate is only 5 kg ha-1. This reduces the seed requirement and cost of the seed. In hybrid rice cultivation, where seed co= st in high i.e. from Rs. 160 to 200 a kg, the SRI = system of cultivation will be very useful.

-&nb= sp;            =          Less water use:<= span style=3D'font-size:11.0pt;font-family:Garamond'> In SRI method, soil is kep= t under aerobic and anaerobic conditions, so water requirement is less. This reduces the cost of purchased irrigation water or cost of diesel etc.

-&nb= sp;            =          Higher yield: Additional 20 to 25% yield= is reported from on-farm farmers field evaluation. = This is due to increased tillering and more effective panicles per hill, and more number of fertile grains per panicle.

-&nb= sp;            =          Less disease and insect incidence:= Due to wider spacing the disease and insect incidence like BPH, GLH and other p= est is be less.

 

Modified SRI = with hybrid rice

 

   &nb= sp;        To get high yield of 10 t ha-1 and beyond, use of inorganic fertili= zer is needed. For each ton of grain yield, 20 kg Nitrogen is taken from soil by plant. For getting 10 tons, atleast 200 kg Nitr= ogen will be taken from soil. Fifty kg Nitrogen will be supplied through organic manures, and remaining 150 kg through inorganic fertilizers, Likewise P2O5 and K20 will be 100 kg and 50 kg, respectively. P and K should be used as basal and N as top dressing in split doses, basal, tillering and panicle initiation stages.

 

   &nb= sp;        Hybrid rice yields are higher than conventional varieties. Its seedling vigor is a= lso better than self pollinated varieties. As its grains per panicle are higher= in number, Potash top dressing has given higher grain filling and better grain= weight. So, for SRI cultivation, inorganic fertilizer @ 150: 75= and 90 kg NPK ha-1, in addition to 5 tones of organic manure as FYM, compost, cakes or vermicompost. So future research should be in area of SRI with inorganic fertilizer with hybrid rice varieties with yield target of 12 tones per ha.=

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