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Table 1. Time of establishment and cumulative rainfall with different rice establishmentmethods, 1995-2000, Raipur, India.Establishment method Event Day of year Cumulative rainfall (mm)Dry-seeded rice Sowing 159 0Establishment 177 131 ± 51Broadcast, biasi rice (moist soil) a Sowing 174 112 ± 52Establishment 193 255 ± 60Biasi (plowing) 219 532 ± 106Transplanted rice Transplanting 219 496 ± 112a 1998-2000 onlySource: Rathore and Sahu (2002).DS is an alternative to transplanting. Changes in the weed flora caused by the shiftto direct seeding and related issues are treated in the third part of this document, andlastly we look at the possibilities and options of more flexible crop establishment andmanagement systems.Improving productivity in the existing DS systemsIn the rainfed lowland rice areas of eastern India (approx. 12.8 million ha) that aresubject to shallow and intermediate flooding depth, biasi (also referred to as beusheningor beusani) is a traditional rice establishment method, popular among farmersin 50% to 80% of the area (Koshta et al 1991, Nayak and Lenka 1988, Tomar 2002).In the biasi system, with the first rains, dry rice seed is broadcast on fields followedby wet plowing in order to control weeds at 20–35 days after emergence and whenthere is 5–10 cm of water on the fields (Fujisaka et al 1993). Rice is able to recoverafter the plowing, provided there is sufficient water in the fields, whereas many ofthe weeds do not. Farmers may also undertake some supplementary hand weeding tocontrol subsequent weed growth.Studies in the 1990s showed that different practices for dry seeding could lead toimproved crop growth and increase the chances of growing a second crop. Dry sowingcould be undertaken before the monsoon has started, whereas sowing in moist soil,as practiced with the biasi system, requires 112 mm on average while transplantingrequires almost 500 mm of rainfall (Table 1). DS rice suffered less from water deficit,resulted in better rainfall-use efficiency (Rathore and Sahu 2002), and gave the bestyields over the three years of study (Table 2). Further, DS rice could be established 16days before sufficient rainfall to moisten the seedbed for biasi and 42 days ahead oftransplanting. Advancing the rice crop increased the chances of a subsequent crop; in1998, DS rice and earlier planting of chickpea gave the best yield and in the followingyear only dry seeding of rice permitted a second crop (Table 2). No second crop waspossible in 2000, a drought year.Direct seeding of rice and opportunities for improving productivity in Asia 203
Table 2. Effects of rice establishment method on rice and chickpea grain yield (t ha –1 ) in anon-station experiment at Raipur, India, 1998-2000.EstablishmentYearCrop method a 1998 b 1999 c 2000 dRice DSR dry 4.61 4.22 3.12DSR moist 4.21 3.61 0.82DSR biasi 3.55 2.72 0.68TPR 3.25 1.69 0.39Chickpea DSR dry 1.10 0.62 NEDSR moist 0.96 0 NEDSR biasi 0.88 0 NETPR 0.69 0 NEa DSR = dry-seeded rice in dry or moist soil, or in the biasi system. TPR = transplanted rice. NE = not established.b Normal year. c Moderate drought year. d Severe drought year.Source: Rathore and Sahu (2002).Similar amounts of cumulative rainfall were required for biasi plowing as fortransplanting (Table 1) and this is related to one of the constraints in the system.Poor rainfall can lead to delayed wet plowing and high crop losses because of weedcompetition. Improved weed management options based on row seeding, interrowcultivation, and herbicides could eliminate the need for wet plowing (biasi) of therice at the tillering stage and provide a pathway to improving crop productivity. Linesowing rather than broadcasting permits interrow cultivation and easier hand weeding,and the application of either preemergence (pendimethalin) or postemergence herbicide(fenoxaprop + chlorimuron ethyl + metsulfuron) provides further options. Weedbiomass was greatest at 20 DAE where rice had been sown into dry soil; at 35 DAE,across the weed management treatments, weed density and biomass were greatest inthe broadcast biasi (Table 3). Weed biomass at 20 DAE was least, across establishmentmethods, with preemergence herbicide and at 35 DAE with the postemergenceherbicide treatment. Across weed management treatments and three sites, DS rice, linesown in moist soil, gave the best yield compared with line sowing in dry soil or thetraditional biasi system (4.05, 3.62, and 2.96 t ha –1 , respectively, LSD 5% = 0.182).Farmers in Java also practice dry seeding, though within different systems thanthose of eastern India. In Central Java, two rice crops and often a vegetable crop areharvested from fields in one year in areas with a total rainfall of about 1,500 mm andwithout supplementary irrigation (Pane et al 2005). In this system, dry-seeded rice(gogorancah) is grown at the beginning of the rainy season, followed by a transplantedrice crop (walik jerami). Both rice crops may be subject to flooding of varying periods,with duration and depth depending on the toposequence. In this labor-intensive system,dry seeding of rice helps farmers make maximum use of the potential growing season.Studies on yield constraints in farmers’ fields examined losses to weeds to determinethe specific scope to increase productivity through improved weed management. Ad-204 Johnson et al
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Improving AgriculturalProductivity
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Bangladeshi experiences with a drum
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AcknowledgmentsIRRI is most gratefu
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The High Barind Tract: a challengin
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irrigation across the entire Barind
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Workshop synthesis
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and, with representatives from the
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Subsistence pressureLand pressure,
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HerbicidesEarlier efforts to introd
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volume). PVS is an effective way to
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Farmers may use wet-seeded DSR as a
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process and distributing HNPV to fa
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an NGO, have successfully collabora
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Workshop discussionParticipants dis
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How can we identify a short-duratio
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to fixed tenancy. The implication i
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Opportunities for improving ricepro
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that the reliability and productivi
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Table 1. Planting dates, direct-see
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Table 2. (A) Mean effect of fertili
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Table 5. On-farm trials of a drum s
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Upper toposequenceYield (t ha -1 )7
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and perennial grasses (e.g., Ischae
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Direct-seeded rice in the HighBarin
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Table 1. Sample selection for costs
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Table 4. Variations in weed managem
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Table 7. Labor requirements (days h
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Table 10. Farmer perceptions of dis
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Farmers (no.)1412108DSRWet-seededDr
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able commercially. Other OFT farmer
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Box 1. Farmers’ comments on DSRPo
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NotesAuthors’ addresses: M.A. Jab
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This paper explores the role of som
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(Olsen method, atomic absorption),
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Mean biomass (g m −2 )1,000.000Fi
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Fig. 3. Log rank abundance of weed
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attested by Fig. 2). Diversity in t
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Bangladeshi experiences with a drum
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Table 1. Grain yield and crop durat
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Table 5. Grain yield and growth dur
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ACEy = 0.0001x + 0.7089Yield (t ha
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Table 11. Partial budget analysis f
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ConclusionsDirect wet-seeded rice u
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A 178% increase in rice production
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Table 1. Components of yield gaps d
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Table 3. Weed management in Comilla
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Table 5. Weed management practices
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Table 7. Significance (P H o ) of t
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Since 2000, there has been an incre
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Identifying varieties for the High
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Table 1. Rice varieties bred by cli
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Table 2. Grain yield advantage of J
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Table 3. Plant height and crop dura
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Table 6. Summary of adoption and sp
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Freeman GH, Perkins J.M. 1971. Envi
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Opportunities for improving rabi cr
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Grain yield (t ha -1 )2.0npp1.5LSD
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In each of the plots, numbers of He
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Table 2. Effect of IPM components o
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Unit plot size was 10 10 m and the
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Yield (t ha -1 )5Straw4321GrainP (g
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Nodulation score3AControl Soil Mo P
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even at low levels of production. B
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Integration of chickpea and other r
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Grain yield (t ha -1 )3.02.51989-99
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Improved Improved Rainfed rainfed C
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Table 1. Preharvest and postharvest
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Greater resistance to Helicoverpa p
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wheat varieties). There is also sco
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Developing seed systems fordissemin
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This paper describes attempts to em
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seed needed to attain the recommend
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Page 168 and 169: for the rabi crop in 2001. Hence, b
Page 170: where farmers decided not to relay-
Page 174 and 175: Table 2. Mean dates of T. aman harv
Page 176 and 177: Table 4. Subsistence pressure and r
Page 178 and 179: Table 7. Subsistence pressure and r
Page 180 and 181: cite the absence of rent as a facto
Page 182 and 183: abi cropping in the HBT through ear
Page 184 and 185: Formulation and dissemination ofimp
Page 186 and 187: in India, for which shorter-duratio
Page 188 and 189: Applied researchOFTsAdaptive resear
Page 190 and 191: Table 1. Recommended package of pra
Page 192 and 193: Table 2. Grain yields (kg ha -1 ) o
Page 194 and 195: Table 4. Grain yields (t ha -1 ) of
Page 196 and 197: Table 6. Mean grain yields (t ha -1
Page 198: constraints present. This in itself
Page 202 and 203: Extending rabi cropping in rice fal
Page 204 and 205: Table 1. Estimates of rice area dur
Page 206 and 207: Yield (kg ha -1 )1,2001,00080060040
Page 208 and 209: Future disseminationThrough dialogu
Page 210 and 211: Direct seeding of rice andopportuni
Page 214 and 215: Table 3. Weed density and biomass a
Page 216 and 217: than in Central Java and many farme
Page 218 and 219: Proportion abundance (log scale)Ran
Page 220 and 221: CAN FIELD BE DRAINED?YesCAN FIELD B
Page 222 and 223: Johnson DE, Mortimer AM. 2005. Issu
Page 224: Zhao DL, Atlin GN, Bastiaans L, Spi
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