Kerala and Tamil nadu were leading states for rice production with own bio diversities and culture. Agricultural universities of both state lead the rice research in both region.
Recently developed RKMP (Rice Knowledge Management Portal ) reveals the research perspective of both universities on their respective rice ecosystems.
Rice ecosystems of Kerala is classified purely based on agroecosystem. It almost coincides with the agro-climatic zones of Kerala.
But, in Tamil nadu the ecosystems were just classified in to upland, semidry and lowland ecosystem. The soil types and the agroecology was not at all considered in tamil nadu while classifying the ecosystems of rice. However, there are rice research stations in Tamilnadu located widely in all agro-climatic zones. The varieties were released in its name ASD, CO, TRY, ADT, TKM, PMK, MDU, etc.
The classification of the rice eco-systems were just based on water availability and elevation (irrigated and rainfed) in Tamil nadu. The regional and climatic factors were not given importance here. But, Kerala takes topography, soil and abiotic factors and variation in resource endowments, and reckoning the seasonal differences in which rice for classifying them.
This basic narrow understanding of the agroecology, by research institutes of Tamil nadu and in contrast the deeper understanding of the ecology in Kerala rice research makes Kerala to march forward quickly in organic farming than Tamil nadu. Tamil nadu farmers have realized this and so they march forward in conserving the traditional seeds and its cultivation.
Such a limited understanding is applied in research and how would we expect the fruitful outcomes from those institutes in Tamil nadu. Only the genetic resources which is available in respective region were able to produce fruitful results for Tamil nadu rice research institutes. The scientific understanding, importantly the holistic understanding is lacking with them.
Such a limited understanding is applied in research and how would we expect the fruitful outcomes from those institutes in Tamil nadu. Only the genetic resources which is available in respective region were able to produce fruitful results for Tamil nadu rice research institutes. The scientific understanding, importantly the holistic understanding is lacking with them.
Kerala Rice ecosystems | Tamil nadu Rice ecosystems |
Taking into consideration topography, soil and abiotic factors and variation in resource endowments, and reckoning the seasonal differences in which rice is grown in the state, eight significant agro-ecosystems are identified as detailed below a. Midland and Malayorum ecosystems - The most predominant system is the viruppu-mundakan sequence practiced on irruppu niloms covering the midlands and the malayoram agro-ecological zone. Viruppu crop on these lands is largely a rainfed crop grown during the South West Monsoon. Generally starting as a dry broadcast crop it ends up in wet conditions. The varieties grown have such plasticity that they are conditioned to growth under a wide spectrum of moisture regimes from moist seedbed to standing water. Mundakan (winter) crop is generally a transplanted crop (Broadcasting with sprouted seed is also practised especially where water is assured) in which rice plant grows throughout under continuous wet conditions. The fag end of the crop might be subjected to moisture stress in some areas if the northeast monsoon tapers off suddenly. Most of the growing period is spent during the northeast monsoon rainfall. b. Palakkadu plains and Chittoor black soil agro-ecosystem. Another major chunk of double-cropped land is the irrigated project commands predominantly the eastern taluks of Palakkadu and Periyar valley command in the Ernakulam district. Prior to the commissioning of the irrigation projects, these were the traditional iruppu and oruppu lands. The main difference between the rainfed and the irrigated practice is that in the latter the viruppu season commences only after the onset of the southwest monsoon (in June) and crop is established through transplanting instead of dry broadcasting. The crop is of medium duration. Commencement of mundakan season is delayed to October-November and continues to be a transplanted crop. Longer duration varieties are preferred under the irrigated system. c. Kuttanadu agro-ecosystem A unique system of rice production is practiced in the rice bowl of the state: the Kuttanadu in Alappuzha and Kottayam districts and kole land in Thrissur district. Being low-lying estuarine lands, these areas are subjected to floods during the two monsoons and salinity intrusion during post monsoon periods. Soon after the northeast monsoon ends in November, bunds (dykes) are raised. Pumping out the water drains these ‘polders,’ sowing is then done wet with sprouted seeds. The growing period is midway between mundakan and summer. Sown in November- December, the crop is harvested in March - April. As the fields are generally below sea level, water from the bordering canal system is drawn by gravity flow and used for irrigation. In some parts an additional crop is taken during autumn or virippu which is sown dry broadcast or wet sown just prior to the onset of monsoon. d.Pokkali agro-ecosystem In areas that are subjected to tidal action and hence the soil is saline, a crop of rice is grown during viruppu taking advantage of the heavy southwest monsoon by a system of flushing out the salt from the land. The system is known as pokkali in central Kerala and kaipaatu in north Kerala. After the harvest of the virippu crop, prawn culture is practiced making use of the tidal flow during the ebb and floods. e. Onattukara agro-eco system Here two crops of paddy is raised followed by pulse crop or oil seeds. Both the paddy crops – Virippu and Mundakan are purely rainfed crops. The soil is sandy textured. It extends in Alappuzha & Quilon districts. f. High range agro-ecosystem The low temperature regime generally prevailing in the high ranges limits the time available for rice production in this area. Only one crop extending to both the southwest and the northwest monsoons is practicable. Paddy production in the high ranges is mainly taking place in the Wayanad plateau where the valley bottoms are relatively broad and extensive. Predominantly it is transplanted crop, commencing in July and harvested in December. Source: Status Paper on Rice in Kerala, S. Leena Kumari, Professor & Head, Rice Research Station, Monkompu, Thekkekkara P.O., Alleppey District. Kerala 688 503 Can be browsed at http://goo.gl/xm8T0 | The rice crop is cultivated both under irrigated and rainfed ecosystem. The upland rice are bunded rainfed or subsequently irrigated. (a) Upland Rainfed and semidry. (b) Rainfed The crop is raised with direct seeding either by broadcasting or sowing behind the country plough or gorru. The crop is depending entirely on the monsoon rain. (c) Semidry The dry seeds are sown either pre or post-monsoon depending on rainfall received or predicted. Later the crop is irrigated when the tanks get filled up with rains and water is received through canals. Low land They are bunded and irrigated, either by river water or tank water. Transplanting is the common practice. However, direct seeding of wet sprouted seeds with the help of drum seeder is slowly getting popular. Source: Status Paper on Rice in Tamil Nadu, Thiyagarajan . K* and Kalaiyarasi . R, *Director, Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore-641 003, Tamil Nadu |
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