Contents & Foreword, Characterizing And ... - IRRI books

More documents

Recommendations

Info

in soil nutritional status, especially for P and pH, which in turn was reflectedin species composition. The results indicate that, under current weed managementpractices, the residual weed flora is strongly governed by hydrologicalfactors with respect to toposequence in addition to soil factors. Futureresearch and weed management options are discussed in the context of thisbaseline characterization of weed communities.A defining characteristic of the agroecosystem in which rainfed lowland rice is grownis the occurrence of noncontinuous flooding of land of variable depth and duration(Zeigler and Puckridge 1995). The Jakenan region in Central Java, Indonesia, with anaverage of
times at 7–8 WAE, 80 labor-days ha –1 being the estimated effort (Fagi 1995). In walikjerami, the crop is usually handweeded only twice, 2–4 wk after transplanting (WAT)and at 6–7 WAT, needing 48 labor-days ha –1 . The extent to which weeds are a constraintto yields has not been accurately determined by on-farm yield gap studies ingogorancah rice but a rapid rural appraisal of fields (Fujisaka et al 1993) suggestedthat weed infestations were higher in gogorancah than in walik jerami and severest inthe low-lying areas. Recently, from three seasons of research-station trials, Bangun etal (1998a,b) estimated that grain yield reductions due to weeds in gogorancah andwalik jerami were about 76% and 45%, respectively, when comparing unweeded plotswith weed-free checks.Improving weed management practices for gogorancah rice invokes many ofthe same issues associated with direct-seeded rice production systems in otheragroecosystems (Mortimer et al 1997, Mortimer and Hill 1999). In the context ofprevailing socioeconomic production domains (Pandey 1998) and the heterogeneousenvironment of rainfed rice, the appropriate integration of agronomic and water managementpractices to ensure rapid crop establishment of a competitive crop stand andfertilizer management and weed control interventions after crop establishment remainimportant adaptive research issues. Equally essential is an understanding ofexisting farm weed management systems and the agronomic and economic constraintsexperienced by farmers. Documentation of the efficacy of farm weed control practicesand of the abundance and diversity of weeds throughout crop growth contributesto a baseline in the analysis of the impact of existing weed control systems and to theex ante assessment of proposed changes in management. Given a priori knowledgeabout the relative competitiveness and ecology of individual weed species, this baselineprovides a precursor to the design of on-farm yield gap trials, which are expensive toconduct (Moody 1993). Of particular importance is knowledge of the weed flora remainingafter normal farmer weeding practices.Apart from general inventories of the weed species present in rainfed rice inIndonesia (e.g., Soerjani et al 1987), no systematic surveys have been conducted tocharacterize the on-farm weed flora of gogorancah rice. The objectives of this studywere therefore to quantitatively describe the weed flora in dry direct-seededgogorancah rice in Central Java from extensive farmer field surveys, to analyze variationin this flora in relation to toposequence and soil characteristics, and to reviewimplications for improved weed management.Materials and methodsSurvey sitesTwenty-five farm sites were chosen in subdistricts within 50 km of the Jakenan experimentalstation of the Central Research Institute for Food Crops in the districts ofPati and Rembang, Central Java, Indonesia. Farms were identified as being in areasof intensive rainfed lowland rice production by the presence of a water reservoir inthe local vicinity and all showed sloping lands (5–30°). At each farm, three positions(upper, mid, and lower) on the toposequence were identified for census of the weedWeed communities of gogorancah rice and reflections on management 271
Page 2 and 3:
The International Rice Research Ins
Page 4 and 5:
Monitoring rainfed and irrigated ri
Page 6 and 7:
ForewordRainfed rice areas are asso
Page 8 and 9:
AcknowledgmentsIRRI is most gratefu
Page 10 and 11:
2 Singh et al
Page 12 and 13:
development, for example, provision
Page 14 and 15:
subecosystems were recognized withi
Page 16 and 17:
Table 3. Methods commonly used in e
Page 18 and 19:
Table 4 continued.Scale of analysis
Page 20 and 21:
Table 4 continued.Scale of analysis
Page 22 and 23:
This included standard countrywide
Page 24 and 25:
deepwater rice ecosystems. The rese
Page 26 and 27:
Table 5 continued.Main MethodologyC
Page 28 and 29:
Table 5 continued.Main MethodologyC
Page 30 and 31:
Table 5 continued.Main Scale presen
Page 32 and 33:
levels of involvement. For example,
Page 34 and 35:
●●●ecosystem classifications
Page 36 and 37:
Conclusionsclearly that they are di
Page 38 and 39:
IRRI (International Rice Research I
Page 40 and 41:
Widawsky DA, O’Toole JC. 1990. Pr
Page 42 and 43:
Rice is the staple food crop for mo
Page 44 and 45:
first working group to identify the
Page 46 and 47:
TropicsSubtropicsTemperateSummer/wi
Page 48 and 49:
ferred it for wide adoption by farm
Page 50 and 51:
ing, remote sensing, and computing
Page 52 and 53:
ice environments will be needed to
Page 54 and 55:
Insects and diseasesInsects and dis
Page 56 and 57:
The completeness of characterizatio
Page 58 and 59:
Table 7. Levels and scales for agro
Page 60 and 61:
Jamin JY, Andriesse W. 1993. Discus
Page 62 and 63:
Tools and methodologiesfor biophysi
Page 64 and 65:
Effect of climate, agrohydrology,an
Page 66 and 67:
to water deficit because the crop
Page 68 and 69:
for different periods of the year:
Page 70 and 71:
depth scenarios (shallow, medium, a
Page 72 and 73:
Water table depth (cm)500Shallow wa
Page 74 and 75:
Simulated yield (kg ha -1 )6,0005,0
Page 76 and 77:
Perception, understanding,and mappi
Page 78 and 79:
and rice yield at regional or more
Page 80 and 81:
SubareaSampling sites:GridTransectR
Page 82 and 83:
was approximately 2,000 m with a to
Page 84 and 85:
kg -1 in 50% of the topsoil and sub
Page 86 and 87:
Table 3. Class medians were calcula
Page 88 and 89:
Hard point dataClay, silt, sandHard
Page 90 and 91:
A. Silt (%) B. 0.5 ccdfC. 0.2 ccdf
Page 92 and 93:
In summary, the chosen geostatistic
Page 94 and 95:
elated over slightly longer distanc
Page 96 and 97:
Miura K. 1990. Genetic features of
Page 98 and 99:
Rainfed lowland rice, growing with
Page 100 and 101:
tively. In 1993, following dry till
Page 102 and 103:
Rainfall (mm)Water table depth (cm)
Page 104 and 105:
Saturated hydraulic conductivity (c
Page 106 and 107:
in the uncompacted C0 plots (6.7 wk
Page 108 and 109:
Clay classified≤ 2% 50 ha (2% but
Page 110 and 111:
NotesAuthors’ addresses: D. Harnp
Page 112 and 113:
target area of a breeding program.
Page 114 and 115:
which is calculated from the estima
Page 116 and 117:
hence grain yield. The three major
Page 118 and 119:
ainfall data for each location. Mea
Page 120 and 121:
such as 1980 and 1996, yield was hi
Page 122 and 123:
Table 1 shows the results of the se
Page 124 and 125:
Grain yield (t ha -1 )3UBN 19942103
Page 126 and 127:
decreased with the use of old seedl
Page 128 and 129:
The use of five genotypes with diff
Page 130 and 131:
Mackill DJ, Coffman WR, Garrity DP.
Page 132 and 133:
In rainfed agriculture, crop perfor
Page 134 and 135:
GrainSite Year Code Group yield San
Page 136 and 137:
Criteria considered for selecting r
Page 138 and 139:
Table 1. Characteristics of the ref
Page 140 and 141:
equired as the quality of the repro
Page 142 and 143:
Cooper M, Rajatasereekul S, Immark
Page 144 and 145:
144 Amien and Las
Page 146 and 147:
As Indonesia’s staple food, rice
Page 148 and 149:
Soil and climate of rainfed lowland
Page 150 and 151:
isky when the crop is planted late.
Page 152 and 153:
The decrease in harvested area only
Page 154 and 155:
than in tidal swamp rice, for which
Page 156 and 157:
Monitoring rainfed and irrigated ri
Page 158 and 159:
and, indirectly, methane emission f
Page 160 and 161:
Radar backscatter (dB)-7ERS windsca
Page 162 and 163:
ERS SAR imageseries2. RSpreprocessi
Page 164 and 165:
Fig. 6. Supervised classification o
Page 166 and 167:
ConclusionsMonitoring of rice crops
Page 168 and 169:
Characterizing soil phosphorusand p
Page 170 and 171:
Table 1. Area and distribution of s
Page 172 and 173:
Table 2. Lowland area (ha) classifi
Page 174 and 175:
Fig. 1. Extractable soil P map (25%
Page 176 and 177:
Characterizing soil phosphorus and
Page 178 and 179:
Table 4. Recommendations for P appl
Page 180 and 181:
Fig. 4. Extractable soil K map of t
Page 182 and 183:
Fig. 5. Extractable soil K map of t
Page 184 and 185:
● acidic pH (< 6)● low organic
Page 186 and 187:
trials, K recommendations for uplan
Page 188 and 189:
O’Brien DT, Blair G, Lefroy R. 19
Page 190 and 191:
Planning and managing rice farmingt
Page 192 and 193:
lowlands is submergence-prone. Ther
Page 194 and 195:
situations and the allocation of re
Page 196 and 197:
estimation of drought were determin
Page 198 and 199:
Table 2. Effect of date of sowing,
Page 200 and 201:
from October to February and a summ
Page 202 and 203:
Table 3. Promising areas for ground
Page 204 and 205:
1. There are possibilities of growi
Page 206 and 207:
mmmm450350250150ASoil moisture useS
Page 208 and 209:
Table 9. Yield a of preflood ahu (a
Page 210 and 211:
Grain yield (t ha -1 )6Farmers’ l
Page 212 and 213:
ReferencesIRRI (International Rice
Page 214 and 215:
network (Sastry 1976). Temperature
Page 216 and 217: Temperature (°C) and solar radiati
Page 218 and 219: Table 1. Characterization of rainfa
Page 220 and 221: in eastern Uttar Pradesh under norm
Page 222 and 223: fluctuations/variations in rainfall
Page 224 and 225: the desirable rainfall period at 50
Page 226 and 227: The radiation values range from les
Page 228 and 229: not affect the growth and developme
Page 230 and 231: Agrohydrologic and drought riskanal
Page 232 and 233: Analytical procedureThe nature and
Page 234 and 235: late because of low rainfall at the
Page 236 and 237: Probability (%)10080604020Vegetativ
Page 238 and 239: 15 August), which may happen twice
Page 240 and 241: texture), then once in two years (5
Page 242 and 243: Characterizing biotic stresses
Page 244 and 245: Characterizing biotic constraintsto
Page 246 and 247: included in these studies. Later st
Page 248 and 249: Average number of insects per sweep
Page 250 and 251: Table 2. Categorization of weed and
Page 252 and 253: Table 5. Properties of individual c
Page 254 and 255: ResultsRelations among pests and cr
Page 256 and 257: Start hereInterview farmers todocum
Page 258 and 259: Table 10. Information used to prior
Page 260 and 261: Interpreting the results of indepen
Page 262 and 263: level. Again, we augment our databa
Page 264 and 265: NotesAuthors’ address: Cambodia-I
Page 268 and 269: flora. The range in elevation acros
Page 270 and 271: Table 1. Soil characteristics of th
Page 272 and 273: Table 3. Weed species recorded and
Page 274 and 275: Proportional abundance (log scale)%
Page 276 and 277: 1.0Echi_colCype_iriMoll_penLind_spp
Page 278 and 279: +3.0Echi_cruMars_creEcli_albLept_ch
Page 280 and 281: indicates the need to deploy broad-
Page 282 and 283: ReferencesBangun P, Pane H, Jatmiko
Page 284 and 285: Socioeconomic characterization
Page 286 and 287: The role of characterizationin ex a
Page 288 and 289: ApproachThe following steps were ta
Page 290 and 291: PriceDS 0S 1P 0P 1dS 0S 1acbD0 Q 0Q
Page 292 and 293: Table 1. Ex ante assessment of rese
Page 294 and 295: Table 2 continued.Ranked byResearch
Page 296 and 297: Table 3. Research resource allocati
Page 298 and 299: NotesAuthors’ address: National C
Page 300 and 301: In addition to the unavailability o
Page 302 and 303: Socioeconomic constraintsFarm sizeF
Page 304 and 305: found that a higher rural labor sup
Page 306 and 307: Table 3. Rice area under HYVs from
Page 308 and 309: Rice varieties in farmers’ fields
Page 310 and 311: Table 9. Constraints for low adopti
Page 312 and 313: vehicle for realizing the untapped
Page 314 and 315: Parthasarathy G, Prasad DS. 1978. R
Page 316 and 317:
Appendix. Agroclimatic zones of Bih
Page 318 and 319:
such that losses are reduced during
Page 320 and 321:
P = 0.5 R [a 2 C r2+ 2 a (1 - a) g
Page 322 and 323:
and Itgaon, however, the plot-level
Page 324 and 325:
espectively, to farmers’ income.
Page 326 and 327:
Factors determining the adoption of
Page 328 and 329:
mining whether or not modern variet
Page 330 and 331:
irrigation schemes in the study are
Page 332 and 333:
Using gender analysis in characteri
Page 334 and 335:
lytical tool used to identify or di
Page 336 and 337:
However, household members have cer
Page 338 and 339:
Table 1. Village characteristics of
Page 340 and 341:
taking care of dairy cattle. On the
Page 342 and 343:
The biophysical environmentThe perf
Page 344 and 345:
Table 3. Seasonal calendar and gend
Page 346 and 347:
Table 4. Crops grown during the kha
Page 348 and 349:
Table 7. Labor input (person-days h
Page 350 and 351:
Table 8. Labor input (person-days h
Page 352 and 353:
Table 10. Cost and returns of rice
Page 354 and 355:
Gender roles in animal husbandryWhe
Page 356 and 357:
farm activities, 25% in nonfarm act
Page 358 and 359:
for rice but also for cash crops su
Page 360 and 361:
Table 15. Access to agricultural in
Page 362 and 363:
Hossain M. 1995. Recent development
Page 364 and 365:
Agricultural commercializationand l
Page 366 and 367:
Conceptual frameworkPopulation pres
Page 368 and 369:
tional average of 18% 1 , and most
Page 370 and 371:
The Dzao live in medium-altitude ar
Page 372 and 373:
Table 1. Selected districts and com
Page 374 and 375:
Table 2. General characteristics of
Page 376 and 377:
markets for their food needs. With
Page 378 and 379:
ther “extensification” in the u
Page 380 and 381:
the productivity of lowland rice ca
Page 382 and 383:
Boserup E. 1981. Population and tec
Page 384 and 385:
Economics of intensive rainfed lowl
Page 386 and 387:
Area (ha)50,00040,000Irrigated30,00
Page 388 and 389:
The economic characterization and i
Page 390 and 391:
Table 1. Rice varieties planted (19
Page 392 and 393:
Table 4. Yield and input use of maj
Page 394 and 395:
TFP, output and input indices200160
Page 396 and 397:
Lynam JK, Herdt RW. 1989. Sense and
Page 398 and 399:
406 Garcia et al
Page 400 and 401:
Increased rice production had alway
Page 402 and 403:
Table 1. Total rice area, average y
Page 404 and 405:
use of water by avoiding seedbed pr
Page 406 and 407:
water often brought with it a varie
Page 408 and 409:
Table 4. Distribution of farm house
Page 410 and 411:
Soil types found in the villages we
Page 412 and 413:
Table 10. Ownership of agricultural
Page 414 and 415:
in a group) at the rate of $60 per
Page 416 and 417:
Table 13. Pattern of loan use (% of
Page 418 and 419:
Labor and employmentTable 16 presen
Page 420 and 421:
Table 17. Incidence of child labor
Page 422 and 423:
Cumulative proportion of income1.04
Page 424 and 425:
Table 21. Cost and return analysis
Page 426 and 427:
Table 22. Estimated rice yield and
Page 428 and 429:
were often burned for disease contr
Page 430 and 431:
landless population reaching 50-60%
Page 432 and 433:
Integration of biophysical andsocio
Page 434 and 435:
opinion regarding what socioeconomi
Page 436 and 437:
1995-96 Rice production (t)TvRd6Rd1
Page 438 and 439:
Farm-gate price of agricultural goo
Page 440 and 441:
ming the distance of all line segme
Page 442 and 443:
Description of the study areaWe com
Page 444 and 445:
Table 1 continued.Variable Unit1994
Page 446 and 447:
CambodiaFig. 4. Main transport rout
Page 448 and 449:
Table 2. Accessibility indicators f
Page 450 and 451:
ice and the model is applied to exp
Page 452 and 453:
Table 3. Summary of estimates of la
Page 454 and 455:
estimation of a system of multinomi
Page 456 and 457:
The availability of low-saline irri
Page 458 and 459:
Table 5. Simulation of effects of i
Page 460 and 461:
NotesAuthors’ address: Social Sci
Page 462 and 463:
that they synthesize fragmented agr
Page 464 and 465:
Framework for exploratory and predi
Page 466 and 467:
and quantify the spatial distributi
Page 468 and 469:
Seventeen different agricultural pr
Page 470 and 471:
self-sufficiency in rice production
Page 472 and 473:
al warming since maintaining or cre
Page 474 and 475:
eturns to purchased inputs due to u
Page 476 and 477:
Francisco SR, Navarrete Jr. RL, Dim
Page 478:
Wade L. 1998. Nutrient research on
show all

Contents & Foreword, Characterizing And ... - IRRI books

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?