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Chickpea (cv. Bari chola 2) was broadcast onto residual soil moisture afterharvest of direct-seeded rice and covered with soil by cross plowing with an ox-drawncountry plow. Rice yield was assessed from one 5-m 2 area of each plot. Total weedbiomass was recorded in two unweeded quadrats per plot at harvest.On-farm verification of the DSR-rabi systemTrials were undertaken in 16 farmers’ fields during the 2003 monsoon season to verifythe productivity of a DSR rice-chickpea system. Chickpea (cv. Bari chola 2) wassown after harvest of Swarna or three shorter duration BRRI dhan cultivars (maturity140–145 days) established by either transplanting or direct seeding. Prior to dry directseeding in June, the land was plowed (at least 3 times) with an animal-drawn countryplow and leveled with a ladder. Seed was sown in lines by hand into furrows openedby a hand-pulled lithao. Seedbeds were established at the same time and seedlingswere transplanted approximately 30 days later following conventional plowing andpuddling operations. In direct-seeded rice, a single application of oxadiazon (375 ga.i. ha –1 ) was made to control weeds, whereas in transplanted rice pretilachlor (450g a.i. ha –1 ) was applied.Field-scale evaluationsEvaluations of three practical methods of direct seeding were undertaken on a fieldscale in three districts of the High Barind Tract during aman 2004. Dry seed of Swarnaand BRRI dhan 31 (duration of 140–145 days) was sown into shallow furrows madeby a manually drawn lithao in several fields managed by a group of farmers who hadpreviously seen the technique used in research trials. The lithao opens three rows at atime into which seed is sown by hand. Fields were leveled with an ox-drawn ladder tocover the seed after sowing. Weed control was by oxadiazon applied after seeding witha single follow-up hand weeding when necessary. Village extension officers, supportedby an NGO, collaborated with researchers to evaluate broadcast sowing of dry seedonto moist soil or drum seeding of pregerminated seed onto puddled soil, each on 13farms. Plot size was 666 m 2 . Weed control was also by a preemergence application ofoxadiazon and hand weeding. Direct-seeded plots were compared with transplantedrice established from seedlings raised in seedbeds sown the same day as fields weredirect seeded. Weed control in transplanted rice involved preemergence applicationof pretilachlor (450 g a.i. ha –1 ) after transplanting, followed by hand weeding.In 2005, fieldwork was concentrated with farmer groups in six villages, in RajshahiDistrict, where farmers planted a field by one of the two following methods of directseeding: Sowing dry seed into moist soil by hand into rows opened by a locallyfabricated furrow opener (lithao). A total of 43 sites were planted by dryseeding between 6 and 29 June. Subsequently, monsoon rain flooded fields,preventing further use of this technique. A hand-pulled drum seeder (model imported from Vietnam) was used to sowpregerminated seed on wet soil at 11 sites. This method was used between29 June and 10 July.Developments in direct seeding of rainfed rice in the High Barind Tract 35
Table 1. Planting dates, direct-seeding method, and monthly rainfall, 2001-04.Rainfall (mm)2001 2002 2003 2004DSR planting date 26-VI dry seed 3-VII wet seed 20-VI wet seed 14-VI dry seedTPR planting date 27-VII 2-VII 27-XI 16-VIIMay 235 95 73 100June 367 312 248 454July 268 228 97 176August 182 341 111 177September 176 252 130 145October 198 95 163 185Previous work had demonstrated that direct seeding can be undertaken on whatfarmers classify as either “highland” or “medium land” fields of this terraced landscape.Both land types were represented in each of the villages where groups planted directseededplots. Herbicide (oxadiazon) was applied 2–4 days after seeding and one handweeding was undertaken by 30 DAS. A comparison plot of the same rice cultivar wasestablished by the farmers’ usual method of transplanting at 45 sites. Transplantedplots were usually weeded twice. The majority of farmers chose to grow either LalSwarna or Sadar Swarna, cultivars that are widely grown in the Barind. The farmergroups operated within a “farmer field school” framework, coming together regularlyto visit plots and discuss progress.ResultsSystem trialRainfall in May and early June was sufficient in 2001 and 2004 for sowing dry-seededrice into moist soil during June (Table 1). In 2002 and 2003, an abrupt onset of themonsoon resulted in flooded fields so pregerminated seed was sown on saturated soilin DSR plots after water levels fell. Drought during July and August 2003 delayedtransplanting until late September, 92 days after DSR. Yields of DSR and DSRH exceededthose of TPR (Fig. 1) for both cultivars, except for 2002 (cv. BR 39) and 2001(cv. Swarna), when the cropping system did not significantly influence yield. Yieldsof transplanted rice in 2003 were severely depressed by drought from early July tomid-August that led to late transplanting, whereas under direct seeding yields werehigher and Swarna outyielded BR 39 by 1 t ha –1 . Over four years, mean yields werehighest from direct-seeded rice (P
Page 2: Improving AgriculturalProductivity
Page 5: Bangladeshi experiences with a drum
Page 8: AcknowledgmentsIRRI is most gratefu
Page 12 and 13: The High Barind Tract: a challengin
Page 14 and 15: irrigation across the entire Barind
Page 16: Workshop synthesis
Page 19 and 20: and, with representatives from the
Page 21 and 22: Subsistence pressureLand pressure,
Page 23 and 24: HerbicidesEarlier efforts to introd
Page 25 and 26: volume). PVS is an effective way to
Page 27 and 28: Farmers may use wet-seeded DSR as a
Page 29 and 30: process and distributing HNPV to fa
Page 31 and 32: an NGO, have successfully collabora
Page 34 and 35: Workshop discussionParticipants dis
Page 36 and 37: How can we identify a short-duratio
Page 38 and 39: to fixed tenancy. The implication i
Page 40: Opportunities for improving ricepro
Page 43: that the reliability and productivi
Page 47 and 48: Table 2. (A) Mean effect of fertili
Page 49 and 50: Table 5. On-farm trials of a drum s
Page 51 and 52: Upper toposequenceYield (t ha -1 )7
Page 53 and 54: and perennial grasses (e.g., Ischae
Page 56 and 57: Direct-seeded rice in the HighBarin
Page 58: Table 1. Sample selection for costs
Page 61 and 62: Table 4. Variations in weed managem
Page 63 and 64: Table 7. Labor requirements (days h
Page 65 and 66: Table 10. Farmer perceptions of dis
Page 67 and 68: Farmers (no.)1412108DSRWet-seededDr
Page 69 and 70: able commercially. Other OFT farmer
Page 71: Box 1. Farmers’ comments on DSRPo
Page 74: NotesAuthors’ addresses: M.A. Jab
Page 78 and 79: This paper explores the role of som
Page 80 and 81: (Olsen method, atomic absorption),
Page 82 and 83: Mean biomass (g m −2 )1,000.000Fi
Page 84 and 85: Fig. 3. Log rank abundance of weed
Page 86 and 87: attested by Fig. 2). Diversity in t
Page 88 and 89: Bangladeshi experiences with a drum
Page 90 and 91: Table 1. Grain yield and crop durat
Page 92 and 93: Table 5. Grain yield and growth dur
Page 94 and 95:
ACEy = 0.0001x + 0.7089Yield (t ha
Page 96 and 97:
Table 11. Partial budget analysis f
Page 98:
ConclusionsDirect wet-seeded rice u
Page 101 and 102:
A 178% increase in rice production
Page 103 and 104:
Table 1. Components of yield gaps d
Page 105 and 106:
Table 3. Weed management in Comilla
Page 107 and 108:
Table 5. Weed management practices
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Table 7. Significance (P H o ) of t
Page 111 and 112:
Since 2000, there has been an incre
Page 114 and 115:
Identifying varieties for the High
Page 116 and 117:
Table 1. Rice varieties bred by cli
Page 118 and 119:
Table 2. Grain yield advantage of J
Page 120 and 121:
Table 3. Plant height and crop dura
Page 122 and 123:
Table 6. Summary of adoption and sp
Page 124 and 125:
Freeman GH, Perkins J.M. 1971. Envi
Page 126:
Opportunities for improving rabi cr
Page 129 and 130:
Grain yield (t ha -1 )2.0npp1.5LSD
Page 131 and 132:
In each of the plots, numbers of He
Page 133 and 134:
Table 2. Effect of IPM components o
Page 135 and 136:
Unit plot size was 10 10 m and the
Page 137 and 138:
Yield (t ha -1 )5Straw4321GrainP (g
Page 139 and 140:
Nodulation score3AControl Soil Mo P
Page 141 and 142:
even at low levels of production. B
Page 144 and 145:
Integration of chickpea and other r
Page 146 and 147:
Grain yield (t ha -1 )3.02.51989-99
Page 148 and 149:
Improved Improved Rainfed rainfed C
Page 150 and 151:
Table 1. Preharvest and postharvest
Page 152 and 153:
Greater resistance to Helicoverpa p
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wheat varieties). There is also sco
Page 156 and 157:
Developing seed systems fordissemin
Page 158 and 159:
This paper describes attempts to em
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seed needed to attain the recommend
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introduced to permit sale beyond th
Page 164:
pesticides, inoculation with benefi
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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
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cite the absence of rent as a facto
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abi cropping in the HBT through ear
Page 184 and 185:
Formulation and dissemination ofimp
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in India, for which shorter-duratio
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Applied researchOFTsAdaptive resear
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Table 1. Recommended package of pra
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Table 2. Grain yields (kg ha -1 ) o
Page 194 and 195:
Table 4. Grain yields (t ha -1 ) of
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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
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Table 1. Estimates of rice area dur
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Yield (kg ha -1 )1,2001,00080060040
Page 208 and 209:
Future disseminationThrough dialogu
Page 210 and 211:
Direct seeding of rice andopportuni
Page 212 and 213:
Table 1. Time of establishment and
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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