1 Innovative Production Technologies for Maximizing Rice Productivity and Profit Dr. R. Rajendran1 and Dr. M. Dhakshinamoorthy2 Food security to the people is the key issue pressing the scientists, bureaucrats and politiciansaround the world. The demand for food grain is escalating day by day due to ever growingpopulation. Among the food grains, rice is one of the important staple foods for world’s partof the population. Almost 90% of the world’s rice is produced in Asia. China is the world’sleading producer, growing nearly two-fifths of Asia’s total on 32 million ha. India possessesthe largest rice area (44 million ha) producing nearly a quarter of Asia. (Moya et al., 2004).About 60% of the rice area in Asia is irrigated which constitutes three-fourths of Asia’s rice(Cassman and Pingali, 1995), Irrigated rice farming plays a vital role in meeting the growingdemand of rice eating population. But the rice production is the challenging enterprise nowbecause of stagnant/declining productivity, increasing production cost and declining profitsin the rice growing countries. The growth rates of rice production declined from 3.25 (1967-84) to 1.5% (1984-96) in Asia (Dawe and Dobermann, 1999). Recent estimates are that riceyields in Asia must increase by about 14% from 2000 to 2010 and 25% from 2010 to 2020(Dawe, 2001). Amidst the on-going efforts on genetic and grain quality improvement, thereis an urgent need to explore whether the present management options meet therequirements of rice plant for achieving high yields. The over all factor productivity is atdecreasing trend which needs to be considered more seriously to make rice farmingprofitable (Cassman and Pingali, 1995). Hence, the present management technologies mustbe fine tuned further to reduce the cost of rice production and increase the profitabilityapart from conserving scarce natural resources, maintaining soil fertility and protecting theenvironment. Rice is the staple food of Tamil Nadu, India, cultivated in an area of about 2.1 millionha producing 7.2 million tones. Rice is grown under three different eco systems viz.,irrigated, semi-irrigated and rainfed conditions. Irrigated rice eco system is the predominantone which is being threatened by issues like resource degradation, declining productivity,escalating input costs and diminishing profitability (Moya et al., 2004). At this juncture, it isessential to develop strategies for sustaining the productivity and profitability of irrigatedrice production in the country as whole. The productivity of semi-irrigated rice (dry sown indry soil and flooded after 30-35 days) largely depends on the crop establishment, water***************************************************************************1. Professor and Head, Krishi Vigyan Kendra, Sikkal, Nagapattinam District, Tamil Nadu 2. Professor of SoilScience, TNAU, Coimbatore, Tamil Nadu
2availability and weed management. Onset of monsoon rain, quantity and distribution ofrainfall decides the productivity of rainfed rice. In any case, the yield gap between averagefarmers and potential farmers can be narrowed down only by disseminating innovativeproduction technologies through effective transfer of technologies.Irrigated eco system Irrigated rice systems in Asia have become one of the most important foodproduction systems in the world. Nearly 75% of the rice area in Asia is irrigated where rice isoften grown in monoculture with two or even three crops a year depending upon the wateravailability. In Tamil Nadu, India, irrigated rice is being cultivated as transplanted or directwet seeded crop. In both the systems, rice is planted in the puddle soil by transplantation ordirect seeding.Transplanted RiceCrop establishment The rice nursery management technologies need to be reemphasized among farmersin order to economically utilize the scarce farm inputs like water, seed, labour and fertilizer.In the traditional wet nursery, farmers use excessive seed and water, spend huge money onlabor. In the conventional wet bed nursery, seedlings do not attain the expected size evenat 25-30 days after seeding (DAS) because of invariably high seeding rate and poor nurserymanagement. The recently introduced Integrated Crop Management (ICM) technology forrice has modified certain crop management practices of the system of rice intensification(SRI) developed in Madagascar to enhance rice productivity and profit to farmers. It involvesthe transplanting of young (15-d) seedlings at wider spacing, mechanical weeding,intermittent irrigation etc. Among the practices, using “young seedlings” is the single mostimportant practice contributing for high yields under the modified SRI system. Planting of15-d old seedlings at one per hill produced higher rice yield than 21-d seedlings in NorthSumatra, Indonesia (Makarim et al., 2002). Production of robust, healthy seedling at 15 DASbecomes the pre requisite for the adoption of ICM (modified SRI) method of rice cultivation.The management techniques for the modified rice mat nursery were standardized at the Soiland Water Management Research Institute Farm, Thanjavur, India (Rajendran et al., 2005).Development of modified rice mat nursery i) Selection of suitable medium – Among the organic materials tried, soil + press mud (a by-product from sugarcane industry) mixture at 1:1 ratio produced robust seedlings. About 1.8 t of press mud is required to raise 100 m2 mat nursery required for planting one hectare of main field.
3 ii) Thickness of mat nursery-The 4-cm thick medium was found to be adequate to produce healthy, robust seedlings in 15 days. iii) Lining for spreading the medium – Polyethylene lining was found to beideal and economical at a cost of about Rs. 250 per 100 m2 of mat nursery. Used polyethylene fertilizer gunnies can also be used for spreading over the seed bed. iv) Seed rate- seed rate of 5-7 kg per 100 m2 of mat nursery was sufficient to transplant 1 ha with one seedling per hill. v) Nutrition – Seed bed medium blended with well powdered with well powdered Dap @ 0.5 g kg-1 of medium produced the healthy, robust and tall seedlings. Drenching of seedlings with 0.5% urea solution at 9 DAS was found to give better seedling growth. Urea drenching is only an optional practice as it depends on the level of seedling growth and fertility status of the seed bed medium use. vi) Input use efficiency – Modified rice mat nursery reduces the land requirement (88%), water use (55%), and saves cost on seed (85-90%), fertilizer (90%) and labour (34%). It is therefore highly economical and affordable to farmers. vii) Savings – It was recorded that the nursery cost can be reduced by Rs.1800/ha by adopting the modified rice mat nursery when comparing the traditional wet nursery. At present, crop establishment is highly critical and challenging because of problemslike water scarcity, escalated labor wages and high rental rates of machineries. Farmerstransplant aged seedlings with more number of seedlings per hill at closer spacing in theirtraditional way. Proper land leveling plays a key role on management practices like cropestablishment, water-nutrient-weed management. For example, in the Cauvery Delta Zone(CDZ), perfect land leveling during the Thaladi rice favors better crop establishment andnutrient management in the succeeding rice fallow pulse crop as experienced by theresearchers and farmers.Nutrient managementLCC guided N management Integrated nutrient management options like various sources of organic manure(Chen et al., 1990), green manure (Medhi and Deka, 1996), bio-fertilizer application(Kannaiyan, 1995), splitting the N doses, use of slow release N fertilizers (Mamaril andVillapando, 1984) and soil test based nutrient use efficiency, but each method has its ownmerits and demerits. International Rice Research Institute (IRRI), Philippines, developed anapproach called, site-specific nutrient management (SSNM) through a partnership oforganizations across major rice-growing countries in Asia, including the CDZ of Tamil Nadu.SSNM is a plant-based approach for applying nutrients to lowland rice at optimal rates andtimes to achieve high yield and increased profitability. It makes optimal use of existing
4nutrients from soil, residues, and manures; applies N fertilizer at the time and amountrequired by the rice crop and applies P and K fertilizer based on crop need, as determinedthrough the omission plot technique (Buresh et al., 2005). SSNM provides guidelines toavoid excessive early use/basal application of fertilizer N, and real time N management usingthe leaf color char (LCC). The LCC is an easy to use and inexpensive tool to more efficientlymanage N fertilizer in rice (Balasubramanian et al., 1999). LCC readings are taken every 7 to10 days starting at 21 DAT and continue until booting (about 55 DAT in Kuruvai and 75 DATin Thaladi). If the LCC reading is less than the critical value of 4 (or 3 for transplanted WhitePonni variety and direct seeded rice,) N is applied @ 35 kg N per hectare in Kuruvai and 30kg N per hectare in Thaladi season.Site-specific P and K management A nutrient omission plot technique is used to determine P and K recommendationsthat enable use of sufficient fertilizer P and K to prevent depletion of soil fertility arising fromthe removal with grain and straw. The use of SSNM has consistently increased profit for ricefarmers across Asia. The benefits of SSNM are often associated with better matching of Napplications with the plant’s need for N and more balanced application of K. Use of theSSNM approach as enabled the identifications of locations where rice yields and profitabilitycan be increased through improved management of fertilizer K. In the Cauvery Delta ofTamil Nadu in southern India, for example, use of SSNM has lead to a new Krecommendation for increasing profit in the New Delta zone. A blanket dose of NPK (with regular application of Zn So4 in the Cauvery Delta) hasbeen recommended for irrigated rice through out the rice tracts in the State irrespective ofsoil and climatic differences. SSNM approach resulted in large scale increases in grain yieldand profit in two distinctly different zones of Cauvery Delta, typically in the order of 8-13%over the blanket fertilizer application (Nagarajan et al., 2004). The on-farm evaluation trialsconducted for four seasons with refined N and K management practices during 2001-2003and demonstration trials during 2003-2004 confirmed the earlier findings. SSNM consistentlyincreased grain yield and profit across seasons at the two diverse experimental sites ofCauvery Old and New Delta during 2001-2003 (Ramanathan et al., 2005).Soil-water-weed management The crop establishment techniques introduced through ICM method includedmechanical weeding and soil stirring by rotating conoweeder or rotary weeder, andintermittent irrigation which had increased rice productivity in the in Cauvery Delta TamilNadu. In the experiments conducted at Tamil Nadu Agricultural University (TNAU) Farm,Coimbatore, modified SRI system showed a savings in irrigation water of 56% to 50% for
5conventional and young seedlings respectively, without a significant effect on grain yield butmechanical weeding and soil stirring improved the soil aeration, enhanced nutrientavailability to the crop thereby increased the number of panicles per unit area, filled grainsper panicle and grain yield (Thiyagarajan et al., 2002). On-farm trials conducted during thewet season 2002 in the CDZ had shown encouraging results about the soil and cropmanagement practices followed under ICM approach (Rajendran et al., 2005). Farmersrecorded higher number of panicles per square meter (322 to 645) and grain yield (5680 to7650 kg per ha) in the ICM plots which represented an increase of 32% to 50% over theirconventional method. The average net profit was Rs. 4800/ha for the conventional methodand Rs.16800/ha for the ICM method. Thus, farmers obtained and additional profit ofRs.12000/ha by adopting ICM. Farmers could get this increased profit because of enhancedcrop productivity and reduced cost of production achieved through modified rice matnursery. The increased grain yield was due to the synergistic effect of better cropestablishment, innovative water, weed and nutrient management practices followed underICM approach (Thiyagarajan et al., 2002).Water saving rice production Rice production in Asia needs to increase to feed an ever-growing population. Butthe water crisis threatens the sustainability of the irrigated system. Rice is sensitive todeclining water availability as it requires more water than any other food crop. At the farmlevel, the water productivity can be increased by reducing the water loss through seepage,percolation and evaporation. Water saving irrigation technologies is receiving renewedattention (Bouman and Tuong, 2001). Since the mid 1980s, many studies have without asignificant reduction in rice yield (Wang, 1992). In the river basin areas/ deltaic conditions,practicing alternate wetting and drying is the difficult task because of the unique landtopography and poor drainage facilities. A new concept of growing rice using less water isaerobic rice: growing rice in non puddled aerobic soil using supplementary irrigation just likeupland crops.Management oriented rice Productivity The ICM of rice crop (square planting of 15 d old seedlings at 1 or 2 seedlings perhill with wider spacing at 22.5 x 22.5 cm, mechanical weeding and soil stirring by rotatingconoweeder, intermittent irrigation and addition of organic manure with judicious use ofinorganic fertilizers and leaf color chart (LCC)-based N management) had shown positivesigns for increasing the productivity of existing varieties in te Cauvery Delta andThamiraparani river basin areas of Tamil Nadu. About 100 adaptive research trials (ART)each in the Cauvery Delta and Thamiraparani river basin area of Tamil Nadu were conducted
6during the wet season 2003-2004 under the State Government sponsored promotion ofmodified SRI scheme for up scaling the technology. The results obtained from both the riverbasin areas had shown enhanced rice productivity by the adoption of ICM (modified SRI)technology. In the CDZ, out of 94 farmers, 17 farmers got less than 5 t/ha of grain yieldwith a mean of 585 kg/ha, representing 10-53% more yield than their conventionalcultivation; 29 farmers received 5-6 t/ha with a mean of 5565 kg/ha and 6-43% more yield;48 farmers received> 6 t/ha with a mean of 6980 kg/ha and 7-65% additional yield. Theresults clearly illustrated that the potential yield of the existing rice cultivars could besubstantially increased by such innovative soil and crop management technologies. Similarlyresults were obtained in the Thamiraparani river basin also. Farmers and farm labourersneed to be trained on the production of robust seedlings through modified rice mat nursery,square planting of seedlings, integrated nutrient management including LCC based Napplication, mechanical weeding and alternate wetting and drying methods.Direct wet seeded rice Irrigated rice is established by transplantation or direct seeding. Direct seeded rice isan ancient practice of rice cultivation in India. Out of 44 million ha of rice area in India, 35%of area is under rainfed lowland ecosystem and 6.4% under rainfed upland (Kannaiyan etal., 2000). Direct wet seeding has been adopted as the most efficient rice planting methodin Asian countries where labor supply is limited and expensive. Approximately a quarter ofrice area in Asia is currently direct seeded (Pandey and Velasco, 2004). The traditionaltransplanting has been steadily replaced by direct seeding as it eliminates labor demands forrice nursery management, and also reduces water requirement to some extent besidesshortening the crop maturity period by about a week. The major factors driving the directseedling methods of weed control, increasing water scarcity and raising cost of farm labour.Crop establishment Although direct wet seeding has many advantages, the direct seeding technologydidn’t spread fast in several rice growing tracts because of constraints like poor cropestablishment and difficult weed management. Crop establishment is critical because of poorwater management especially at the time of early crop establishment. Following are sometips for successful crop establishment in direct wet seeded rice. Use good seed itself could enhance yield by 5-20% Perfect land leveling Good drainage all around the field Uniform sowing with optimal seed rate Initial weeding though mechanical weeders or pre-emergence herbicides
7 Good water management Integrated nutrient management Improved agro-techniques for direct seeding and associated crop managementpractices need to be developed. Broadcasting of pre-germinated seeds in the puddle soil isthe traditional method of crop establishment. In broadcasting method, excess seed rate isused leading to competition between rice plants resulting in poor crop yields. IRRI,Philippines has developed a drum seeder for sowing seeds at the optimal rates andappropriate spacing. The performance of the drum seeding technology was evaluated inmany of the rice growing countries in Asia including India under the Crop ResourcesManagement Network (CREMNET) programme. It is really a break through in direct wetseeding technology as it established a uniformly good crop stand with saving of preciousinputs like seed, water and labor. Drum seeded rice recorded higher net returns thanmachine transplanted and broadcast seeded methods in Karnataka, India (Manjappa et al.,2004).Weed management It is very difficult to produce economic yields without good crop managementincluding weed control in direct seeded rice even from varieties with high yield potential. Butweed problem is more serious, resulting in zero yield under the dry seeded upland situationthan under direct wet seeded or transplanted rice. It is necessary to provide weed freeenvironment during the early period of crop growth for the direct sown rice. In direct seededrice first 30-35 days after seeding are considered to be the critical period of weedcompetition. The pre-emergence herbicide pretilachlor plus safener @ 0.3 kg ai/ha can besafely applied at 3-4 DAS to effectively control grasses and broad leaved weeds without anyphototoxic symptom on the growing rice crop (Rajendran and Kempuchetty, 1999).Herbicides can be applied safe at the very early crop growth (0-5 DAS) when mixed withsafener chemicals in order to avoid damage to the emerging rice seedlings. Although,chemical means of weed control in direct wet seeded rice becomes inevitable and giveseffective weed control, none of the individual weed control can be achieved (Kandasamy etal., 2000). The IWM practices include summer ploughing, use of weed seed free seeds,perfect land leveling, good water management and efficient weed management practicesviz., adopting both chemical and mechanical methods of weed control.Water management Water management during early crop establishment stage is critical for ensuringoptimal plant population. Water should be drained 18-20 hours after seeding in the directwet seeded rice. Ensuring optimism soil moisture up to 7 days of sowing is very important
8for uniform germination of seeds. Water level can be maintained thereafter depending uponthe growth of the rice seedlings. Draining water during the early tillering stage around 30thday facilitates proper soil aeration and better tiller production. Alternate wetting and dryingis the efficient method of water management up to flowering stage, provided if the fields aresupported with good drainage channel all around. Wetting and drying paves way for highweed incidence. But application pre-emergence herbicide solves this problem to a certainextent. Water should be drained 10 days before harvesting which in turn helps for fastergrain maturity.Economics On-farm farmers’ participatory demonstration trials conducted in about 40 locationsby the Tamil Nadu Rice Research Institute, Aduthurai revealed the better performance ofdirect seeded rice under puddle condition using drum seeder. Direct drum seeding produced9-12% increased net income over the traditional transplanted rice crop. The increasedreturns are due to reduced cost of cultivation to the tune of 15-20% over thetransplantation method (Kannaiyan et al., 2000).Semi-dry rice ecosystem Rice is being grown under diversified situations. In Tamil Nadu, water scarcity andnon-availability of labor compel the farmers to go in for single crop of rice sown in dry soiland subsequently brought under submerged condition on receipt of rain or canal water. TheCDZ, granary of Tamil Nadu State met with severe water scarcity during 1986 during whichtime entire rice belt was covered under semi-dry rice crop and reaped yield comparable withtraditional transplanted rice. In few dry districts like Ramanathapuram, Sivaganga andPudukkottai, rice is dry sown and later on irrigated through monsoon rain or stored rainwater in tanks/lakes. In the Nagapattinam district of CDZ, farmers cultivate rice by dryseedling which is brought under submerged state either with canal water or North Eastmonsoon rains. Such type of semi-dry ecosystem is sporadically increasing in the ricegrowing districts of Tamil Nadu and production technologies need to be fine tuned tomanage drought and weed problem. In direct sown rice culture, weed problem is severe,reducing the rice yields up to 97% under uncontrolled situation (Saxena and Vaishya, 1993).Following are the critical issues deciding the productivity semi-dry rice. Good land preparation and land leveling Pre-monsoon seeding at appropriate time Early crop establishment with good weed management Soil and crop management strategy to escape drought
9 Seeds are soaked in 1% KCl solution for 10 hrs and then shade dried until the seedsattain the original moisture level. Such type of seed hardening enables the sprouting youngseedlings to withstand early drought because of the KC1 treatment. Osmopriming andhardening of seeds can be successfully integrated to enhance the vigor of coarse and finerice and osmohardening seeds with CaCl2 revealed efficient seedling establishment (Basra etal., 2004). Field is ploughed to a fine tilts and applied with P and K enriched FYM @ 750kg/ha. The dry seeds are sown by broadcast or seed drill at the appropriate week coincidingwith onset of monsoon rains in the few places of CDZ. Application of pre-emergenceherbicide pretilachlor plus followed by the hand weeding was very effective in controlling theweeds with the maximum weed control efficiency of 855 (Rajendran and Kempuchetty,1999). Rice crop is brought under submergence at 30-40 days with the help of rain water orcanal water. After the submergence, N and K fertilizers are top dressed as followed in thecase of transplanted rice.Rainfed rice Rainfed upland constitutes about 19 million ha around the world under a wide rangeof management practices varying form shifting cultivation to highly mechanized systems. InAsia, upland rice constitutes a significant part of the rice area in India, Bangladesh,Indonesia, the Philippines, Thailand, Lao PDR, Vietnam and Myanmar. Yields of upland ricehave remained low (< 1 t/ha), where as lowland rice yields have improved substantially overthe years (Galinato et al., 1999). In Tamil Nadu, India the situation is entirely differentwhere rainfed rice is sown in dry soil and later flooded with the help of stored rain wateravailable in huge lakes/tanks or by the North East monsoon rain. Such type of ricecultivation is being practiced in dry districts like Ramanathapuram, Virudunagar, Sivagangaand Pudukkottai. Direct seeding could be an alternative to transplantation of rice, but poorgermination, uneven crop stand and high weed infestation are among the min constraints toits adoption (Du and Tuong 2002). The success of rainfed rice cultivation depends on the adoption of followingtechnologies, Good land preparation prior to the onset of monsoon Choice of drought tolerant variety Seed treatment to withstand drought and pest and disease incidence Appropriate time of sowing to harvest the monsoon rain Early crop establishment and management Nutrient management with effective water management Water harvesting and moisture conservation to escape and resist drought effect.
10Aerobic rice In Asia, more than 50% of the water used for irrigation is used to irrigate rice(Barker et al., 1999). Irrigated rice in Asia produces about 75% of the worldwide riceproduction (IRRI 1997). However, this irrigated ecosystem is increasingly threatened bywater shortage. Therefore, there is urgent need to decrease water use in rice productionand increase its use efficiency. The adoption of aerobic rice is facilitated by the availability of efficient herbicides formanaging weeds and seed treatment technologies. In China, case studies showed yieldsto vary from 4.5 to 6.5 t/ha, which was about double that of traditional upland ricevarieties and bout 20-30% lower than that of lowland varieties grown under floodedconditions with 60% reduced water use (Wang, 2002). Castaneda et al., 2002 indicatedthe water use from transplanting to harvest under aerobic rice as 650-830 mm and 1350mm under flooded conditions. Because water use decreased relatively more than yield,water productivity under aerobic cultivation increased by 20-40% over that floodedconditions. The rice area in CDZ is in descending order due to poor rainfall and non availabilityof Cauvery water. Among the three seasons, Kuruvai season is the potential period forgrowing rice owing to the availability of very good sunshine, less pest and diseaseincidence and better crop growth. The water scarcity very much affected Kuruvai rice inthe Delta. This makes an imperative change of the existing cropping pattern duringKuruvai season and farmers are advised to cultivate non-traditional crops in the Delta. Inthe New Cauvery Delta, soil is sandy loam in nature which could be effectively utilized forgrowing aerobic rice. Research on aerobic rice production should be intensified forsustaining the rice production in the traditional rice growing tracts. Aerobic rice could be tried as suitable alternate strategic crop in the New CauveryDelta of Tamil Nadu by best utilizing the rainfall and or available surface/ground water inorder to stabilize rice production in the region. A successful change from flooded to aerobic rice production requires the breeding ofspecial aerobic rice varieties and the development of appropriate water and cropmanagement practices.Future of rice farmers and rice research Rice farmers in developing countries are poor and caught in a cycle of endlesspoverty. Farmers can benefit from technologies that boost production and/or increasetheir income and employment. Increases in rice production and farmers’ income depend
11largely on enhanced productivity and efficiency of the rice production system. Focus needto be given based on the farmers’ size of land holding and capabilities. For very poorfarming households and marginal farmers, the priority is not so much yield, but, rather,the lessening of risk. Evolving high yielding cultivars is the first priority irrespective of the rice ecosystems. However, the productivity of exiting varieties under the irrigated rice ecosystemcould be enhanced by fine tuning the crop management. The success stories about theICM or modified SRI revealed the potential prospects for boosting irrigated riceproductivity through innovative crop and soil management approaches. Evolving highyielding cultivars/hybrids, fine tuning of integrate crop management, integrated peatmanagement, integrated peat management, production of quality grains are some of theissues to be borne in mind or making the irrigated rice farming more sustainable. Following are some of the broader areas of rice research being intensively taken upfor increasing the livelihood of the rice growers and rice eating population in general. Applying agricultural biotechnology to produce salt and drought tolerant rice cultivars Evolving new plant types for maximizing rice productivity especially I the irrigated rice eco system Enhancing nutritional quality of rice grain through breeding and biotechnologies approaches Integrated rice crop management with fine tuning of production technologies to reduce the cost of production and enhance productivity. Assessing climate changes and its effect on rice production and adaptive technologies Mechanization of rice farming to sustain rice productivity of rice growers and nutritional quality of consumers. Intensification research on conserving natural resources like land, water and labor.ReferencesBalasubramanian V, Morales AC, Cruz RT and Abdulrachman, S. 1999. Nutr. Cycling Agroecosyst. 53, 59-69.Barker R, Dawe D, Tuong Tp, Bhuiyan SI, Guerra LC. 1999. The outlook for water resources in the year 2020; challenges for research on water management in rice production. In: Assessment and orientation towards the 21st century. Proceedings of
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