RICE RATOONING - IRRI books - International Rice Research Institute

228 RICE RATOONINGTable 1. Estimate of possible areas for rice ratooning in Kerala, India.Cropping situation with main characteristicsModan lands – rainfed uplandsPalliyal lands – terraced uplandsWhere two crops are possible by irrigationWhere only one crop is possible for wantof irrigationTypical double-cropped wetlands of midland regionWith assured water supply for both seasonsWithout assured water supply at posttiliering stageof rabi cropKoottumundakan lands – varietal mixture withtwo harvestsKuttanad – lake area below sea level, southerndistrictsKole – lake area below sea level, Central KeralaPokkali – saline areasWaterlogged low flooded areasPoonthal padam – structureless soilsOnattukara – coastal sandy areasHigh-altitude areasTotalArea(thousand ha)20102036716015541027223023740Possible areafor ratooning(thousand ha)––20–8010–––11–8120Typical double-cropped wetlandsAbout 160,000 ha are estimated to be seriously affected by drought at the posttilleringstage of the rabi crop. This risky rabi crop can be replaced by a ratoon crop,which can be harvested before the drought sets in. The irrigation water saved by sucha duration reduction can be used for stabilizing the major portion of the rabi crop.Koottumundakan landsIn about one-third of the 15,000 ha in this system, a practice similar to ratooning isused to obtain heavy straw yields. In the remaining area, the system is practicedeither to drastically reduce cultivation cost or to avoid machinery power whenharvest of the first crop and planting of the second crop overlap. This area of about10,000 ha can be conveniently brought under ratooning.Waterlogged low flooded areasThese lands are at present planted to tall, lodging-prone varieties with low yields. Inidentifying varieties of semidwarf stature with tolerance for ill-drained low floodedsituation, we have found a few promising cultivars. These cultivars have also beenfound suitable for ratooning. Thus, at least 1,000 ha in these areas can be broughtunder ratooning.Poonthal padamAbout 2,000 ha of rice in this situation also require a change from the tall varieties tothe semidwarfs, to avoid losses from lodging. A changeover to such varieties, ifcombined with ratooning, will allow the land a longer dry period, consideredbeneficial for such structureless soils. Sulfide injury to seedlings after rabi planting isa usual problem in these lands, and reduced tillage is considered useful in minimizing