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10 days of broadcasting, to low plant populations associated with weedy, poorlyleveled seedbeds at many sites where the drum seeder was used. This was the firstexperience of broadcasting aman or using the drum seeder for extension workersand farmers. Tillage at many sites was undertaken only a few days prior to planting,leaving insufficient time for weed suppression in a stale seedbed; laddering was alsoinadequate. The sites brought to yield indicate the potential for wider adoption ofdirect seeding, provided farmers have sufficient knowledge of how to manage thesealternative planting practices. Rice grain yields, averaged across all cultivars chosenby farmers, were similar for transplanting, broadcast planting of dry seed, or drumseeding of sprouted seed (Table 6).Median planting dates for broadcasting and drum seeding were 25 and 20 daysearlier, respectively, than transplanting. This resulted in median harvest dates of 15November for broadcast plots, 11 November for drum seeding, and 20 Novemberfor transplanting with harvest continuing in transplanted fields for a week longerthan in direct-seeded plots (Table 6). Harvest dates of long-duration cultivar Swarna,planted at only four sites, ranged from 7 to 30 November for direct seeding and from19 November to 6 December for transplanting. These dates indicate when farmersactually harvested rather than when grain was sufficiently mature so there may havebeen instances when the harvest was delayed. The data do, however, demonstrate howdirect seeding can bring forward the rice harvest to allow farmers the opportunityfor timely planting of rabi. All participants were encouraged to plant chickpea and amedian sowing date of 25 November was achieved. The median sowing date on plotsthat had previously been direct seeded with rice was 21 November (ranging from 6November to 7 December), some 7 days before the planting of transplanted rice plots(11 November to 18 December).Dry direct seeding, wet seeding with the drum seeder, or transplanting all producedsignificantly similar mean yields (P = 0.52) across field-scale evaluations conductedby six farmer groups planting in 54 fields in Godagari upazilla in 2005 (Fig. 3). Themean difference between transplanted and direct-seeded (dry and wet seeding pooled)rice yields was 0.04 + 0.117 t ha –1 . There was also no significant effect of field locationon the toposequence (P = 0.623), with highland fields producing 5.35 ± 0.136 tha –1 and medium-land fields 5.41 ± 0.076 t ha –1 . During 2005, farmers chose to plantone of two Swarna cultivars. Analysis of harvest dates (Table 7) provides furtherevidence that direct-seeded crops have a shorter field duration (P = 0.002) and, mostimportantly for farmers wishing to establish rabi crops on residual moisture, they canbe harvested earlier.The labor input needed to establish dry-seeded rice using a lithao averaged 79person-hours per ha compared with farmer estimates of 240 hours per ha for uprootingand transplanting seedlings. There is an additional benefit that no rice nursery isneeded. At least three people are needed in a field when using the lithao, two to pulland one to steer, but farmers did not find that it was too arduous to use. Even largerlabor savings are associated with drum seeding as the implement can be pulled byone person. On-farm observations indicated a mean of 3.8 hours for establishing 1 haof rice. Herbicide use reduced weed control time in dry-seeded crops to a mean of 84Developments in direct seeding of rainfed rice in the High Barind Tract 41
Upper toposequenceYield (t ha –1 )76Lal SwarnaSadar Swarna5432DSR WSR TPR DSR WSR TPRMid toposequenceYield (t ha –1 )87Lal SwarnaSadar Swarna6543DSR WSR TPR DSR WSR TPRFig. 3. Mean yields of two rice cultivars established by three methods in the aman seasonof 2005 in Rajshahi District. Yields were recorded from field-scale evaluation of methods byfarmer groups. DSR = dry direct-seeded rice; WSR = pregerminated seed planted by drumseeder; TPR = transplanted rice (seedbeds established on day of direct seeding).hours per ha compared with 590 hours in conventionally managed transplanted ricefor which at least two hand weedings are needed.Discussion and conclusionsA single rice crop each year combined with land pressure and a high proportion ofshare-cropping and other tenancy arrangements in the Barind places a premium onoptimizing rice yield for household food security, particularly for those cultivatingsmaller areas (Mazid et al 2001, 2003). Mean farm size is 0.76 ha and 40% of rice42 Mazid et al
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 and 44: that the reliability and productivi
Page 45 and 46: Table 1. Planting dates, direct-see
Page 47 and 48: Table 2. (A) Mean effect of fertili
Page 49: Table 5. On-farm trials of a drum s
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
Page 109 and 110:
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
Page 154 and 155:
wheat varieties). There is also sco
Page 156 and 157:
Developing seed systems fordissemin
Page 158 and 159:
This paper describes attempts to em
Page 160 and 161:
seed needed to attain the recommend
Page 162 and 163:
introduced to permit sale beyond th
Page 164:
pesticides, inoculation with benefi
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 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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