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Seasonality of ecosystem respiration in a double-cropping paddy field in Bangladesh  [PDF]
M. S. Hossen,M. Mano,A. Miyata,M. A. Baten
Biogeosciences Discussions , 2011, DOI: 10.5194/bgd-8-8693-2011
Abstract: Ecosystem respiration (RE) from cultivated ecosystems is important for understanding the role of these ecosystems in the global carbon balance. To evaluate carbon dynamics in a double-rice cropping paddy field, we conducted long-term measurements at Mymensingh, Bangladesh in 2007 using a tower-based eddy covariance technique. The study objectives were to investigate the diurnal and seasonal variations in RE and to develop and evaluate empirical models for predicting variations in RE using environmental parameters. We found that the diurnal pattern of RE was driven by soil temperature (Ts) whereas the seasonal variation in RE was controlled primarily by Ts and soil water content (SWC). Under high biomass conditions, Ts plays a dominant role in the magnitude of CO2 release. Both the amount and magnitude of RE variation were larger in the "Boro" dry-season rice growing period from late winter to mid-summer than in the "Aman" wet-season rice growing period from late summer to early winter. Annually, the ratio of RE to gross primary production (GPP) was 0.67, indicating a net sink of carbon; the two growing seasons had RE/GPP ratios of 0.58 and 0.52. A model using Ts, SWC, and aboveground biomass predicted daily RE with R2 values of 0.87 and 0.62 for the Boro and Aman seasons, respectively.
Effect of Nitrogen and Water Management on Methane Emission of Boro Rice Cultivation in Bangladesh  [PDF]
Israt Zahan, Shahadat Hossen, Akhter Hossain Chowdhury, Abdul Baten
Journal of Geoscience and Environment Protection (GEP) , 2018, DOI: 10.4236/gep.2018.67007
Abstract: Water and nitrogen are two key elements required for successful rice cultivation. We examined the responses of nitrogen and water management on methane emission of Boro rice in the field laboratory of Bangladesh Agricultural University research farm, Mymensingh. Three treatments were studied in the field experiment viz, T1: Control plot (no nitrogen fertilizer), T2: Urea super granule (78 kg N/ha), T3: Prilled urea (104 kg N/ha) with three replications under two water management of Continuous Standing Water (CSW) and Alternate Wetting and Drying (AWD). Air samples were collected by the closed-chamber method and methane gas was determined by gas chromatography. The highest CH4 emission was found from CSW plots and the lowest from AWD plots. Under CSW condition, the effects of urea treatments on CH4 emission were not significant. In case of urea treatments, the highest CH4 emission was observed from treatment T3 under CSW condition and T2 under AWD condition and the lowest emission was from the control treatment. The overall results suggest that prilled urea and urea super granule should be applied under AWD and CSW condition, respectively to keep less CH4 emission from irrigated rice agriculture.
Seasonal Effect of Seedling Age on the Yield of Rice  [PDF]
Amina Khatun,M.I.U. Mollah,M.H. Rashid,M.S. Islam
Pakistan Journal of Biological Sciences , 2002,
Abstract: An experiment was carried out at the net house of the Department of Agronomy, Bangladesh Agricultural University, Mymensingh using four seedling ages 30, 45, 60 and 75 days, for transplant rice during July to November 1995 in transplant Aman (T. Aman) season and during November 1995 to May 1996 in Boro season. The highest grain yield was obtained from 45-days old seedlings in both seasons. Regression models prepared for T. Aman and Boro seasons separately could explain the yield variations 77.1% and 68%, respectively due to seedling age.
Impact of Irrigation on Food Security in Bangladesh for the Past Three Decades  [PDF]
M. Wakilur RAHMAN, Lovely PARVIN
Journal of Water Resource and Protection (JWARP) , 2009, DOI: 10.4236/jwarp.2009.13027
Abstract: Bangladesh has made impressive progress in agriculture sector in the last three decades and has almost be-come self-sufficient in food grain production. This is a tremendous achievement owing to its small territory and huge population and this was achieved through agricultural mechanization and modernization. Irrigation is one of the leading inputs has direct influence to increase yield, food grains production and plays vital role for ensuring food security in Bangladesh. The present study examined the growth of irrigated area and its impact on food grain production during last three decades. Time series data were used for the study. Differ-ent statistical methods such as mean, percentage, linear and exponential growth model were applied for get-ting meaningful findings. Various technologies have been used for irrigating crops which have contributed to rapid expansion of irrigated area. The conventional irrigation methods (Low Lift Pump, Dhone, Swing Bas-ket, Treadle Pump etc.) were replaced by modern methods (i.e Deep Tube Well and Shallow Tube Well). In addition, surface water irrigation also sharply declined, losing its importance due to lack of new surface irri-gation project and the ineffectiveness of earlier project. Groundwater covered 77 percent of total irrigated area and major (62%) extractions occurred through Shallow Tube Wells (STWs). The rapid expansion of ground water irrigation in respect to STWs irrigation was due to government’s withdrawal on restrictions on tube well setting rule, encouraging private sector and the cost effectiveness of Chinese engine which have been affordable to the small and medium farmers. Irrigated area thus, increased by about three times and cropping intensity also increased from 154 to 176 percent. Boro rice, an irrigated crop, consumed 73 percent of the total crop irrigation and contributed to a greater extent in total rice production in Bangladesh. Boro rice alone contributed to 55 percent of total food grain and was also highest (3.44 MT per hectare) compared to aus rice (1.66 MT per hectare) and aman rice (1.99 MT per hectare) per unit production. Consequently, the cultivated area of boro rice increased by 1168 to 4068 thousand hectares. The higher productivity of boro rice has almost helped the nation to meet her food requirements (about 24 Million MT). Boro rice production was highly correlated (r = .978) with irrigated area. Expansion of one hectare of irrigated area added 3.22 MT of boro rice in Bangladesh. Finally, the study suggested for expansion of irrigated areas (ground water and surface water),
Ratooning Ability of Photoperiod-Sensitive Rice Varieties Transplanted in the Boro Season  [PDF]
B.C. Roy,M.A. Hossain,M.A. Rahman
Pakistan Journal of Biological Sciences , 2004,
Abstract: Field experiment was conducted at the Bangladesh Rice Research Institute, Charbadna farm, Barisal, from boro 2001 to aman 2002. Seven photoperiod-sensitive rice varieties including three fine grain aromatic varieties were transplanted in December 15 and December 30, 2001. After harvest of boro crop the ratoons, came out from the remaining straw and base of the hills, were allowed to grow and in the succeeding aman a good harvest was obtained from those ratoons. In the boro season, the highest yield was obtained from BRRI dhan41 followed by BR23 (7.51 and 7.06 t ha-1, respectively). The yield of aromatic varieties was about 5 t ha-1. The ratoon-yields of both aromatic and non-aromatic varieties in the succeeding aman season were also encouraging and produced about 2 t ha-1, which was more than the average yield of local varieties normally cultivated in the transplanted aman season in that region. The highest yield was obtained from BR23 (2.87 t ha-1) followed by BRRI dhan37 (2.63 t ha-1). From this experiment, it was revealed that the photoperiod-sensitive rice varieties could be planted in the early boro season and the ratoons from this crop also produced a good harvest, might be a low-cost rice cultivation technique in those areas, where crop establishment in the transplanted aman season is somewhat difficult due to early intrusion of tidal water in the field at the end of boro season.
Performance of Different Genotypes/Cultivars to Blast Disease of Rice in Boro and T. Aman Crop in Bangladesh  [PDF]
B.K. Mohanta,M.R. Alam,M.E. Kabir,M. K. Anam
Asian Journal of Plant Sciences , 2003,
Abstract: Twenty-eight bred restored lines and four standard checks were screening for resistance to blast disease of rice during the T. aman and boro season. The breakout and severity of per cent leaf area diseased were recorded under natural infection. On the basis of disease intensity, three were highly resistant, 12 resistant, 16 were moderately resistant and 1 was moderately susceptible at T. aman season and at boro season 3 line s were found to be highly resistant, 8 resistant, 17 moderately resistant and 4 were moderately susceptible. Wide range of variation was observed regarding resistance among the entries. Variations were also found on the basis of season. Considering both seasons, the accession numbers 56, 57, 64, 66, 71 and 73 showed comparatively better performance against above mentioned rice disease.
Rice Straw Losses and its Impact on Livestock Rearing in Bangladesh  [PDF]
M. Al- Mamun,M. A. Akbar,M. Shahjalal,M. A. H. Pramanik
Pakistan Journal of Nutrition , 2002,
Abstract: The existing practice of storing rice straw, routes of straw losses and problems related to livestock rearing in rural areas were studied in four selected villages of Mymensingh district of Bangladesh. The base line information on storage system of rice straw and livestock rearing problems were collected through PRA technique using a pre-designed questionnaire. From the survey it was identified that majority of the farmers stored rice straw traditionally making stack on the ground in unroofed condition and that caused considerable damage and losses of straw resulting shortage in the availability of rice straw for animals. Farmers reported that straw is lost in three stages - during harvesting, processing and storage condition. Harvesting loss was accounted for about 8 and 10% for Boro and T. aus straw, respectively. In wet season 25 and 23% of Boro and T. aus straw respectively, was lost during processing. About 18-20% of straw was lost during storage, which was mainly due to earthen evaporated gas, rat, termites, anjona (a reptile pest), poultry birds and excessive rainfall. In case of storage of rice straw the single most common solution for many problems as recommended by the farmers was to improve storage system. It may be concluded from the above results that traditional storage method leads to significant loss of rice straw resulting in feed shortage and impaired livestock productivity.
Indices of precipitation extremes in Southern Portugal – a geostatistical approach  [PDF]
R. Dur?o,M. J. Pereira,A. C. Costa,J. M. C?rte-Real
Natural Hazards and Earth System Sciences (NHESS) & Discussions (NHESSD) , 2009,
Abstract: Most of the actual studies and previews of future rainfall patterns, based on past observed records for Mediterranean climate areas, focus on the decline of the rainfall amounts over the years, and also on the increase of the frequency of heavy/intense rainfall events particularly in the winter season. These changes in heavy rainfall events may have severe implications and impacts on soil erosion resulting in increased soil degradation risks. The objective of the present work is to evaluate the spatial distribution of extreme precipitation events in Southern Portugal, using a geostatistical approach to assess the relationships between spatial and temporal extreme rainfall patterns. The used dataset comprises a set of 105 stations' records of daily precipitation within the period 1960–1999. Two indices of extreme precipitation were selected to be computed based on the daily precipitation observation series: one representing the frequency of extremely heavy precipitation events (R30) and another one characterizing flood events (R5D). The space-time patterns of the precipitation indices were evaluated and simulated using a geostatistical approach. Despite no significant temporal trends were detected on the calculated indices series, the space-time decadal patterns are becoming more continuous in the last two decades than the previous ones.
A Study on Price Spreads of Major Crops in Selected Markets of Bangladesh
Mohammad Ismail Hossain,Mohammad Nurul Huda,Mst. Esmat Ara Begum,Md. Akhtaruzzaman Khan
Journal of Applied Sciences , 2004,
Abstract: The study was conducted to examine the producer`s share to consumer`s prices to understand the level of marketing efficiency of major crops (rice, wheat and jute) with the help of primary data collected randomly from 55 intermediaries. Out of the intermediaries interviewed 17 was for rice, 17 was for wheat and 21 was for jute in different market levels of Bangladesh. In the study areas, there were four tiers of market/market levels viz. primary market, secondary market, higher secondary market and terminal market. Farmer`s share of consumers` taka of Aman and Boro paddy/rice were 71 and 72%, respectively. In wheat marketing chain, the share of farmer`s in retail prices was 66%. The farmers` share to consumers` prices was 53% for white jute and 54% for tossa jute. Amongst the business intermediaries involved in rice, wheat and jute trading, millers received highest net marketing margin (21% total net margin of all intermediaries) in case of rice (Aman and Boro), retailers (57%) in case of wheat and exporters in case of jute (57% for white jute and 39% for tossa jute). Farmers` net share of consumer`s prices is lower for wheat than rice. Total marketing cost is higher in case of wheat and jute than rice. Rice market appeared more efficient followed by wheat markets. Jute markets were less efficient in terms of farmer`s gain than rice and wheat markets. Bangladesh almost becomes a mono-crop (rice) growing country (covering 78% of net area cropped) because marketing system favours more farmers share to consumers paid prices than any other crop.
Rice Farmers` Returns in Selected Area in Jessore District of Bangladesh  [PDF]
Shaikh Moksadur Rahman,Jun TAKEDA
Journal of Applied Sciences , 2006,
Abstract: Small parcel of land not only act as constraints to investment, but also deprive farmers of access to formal credit, inputs and other institutional services required for improving agricultural practices, in terms of production and marketing. The study was based on an interview conducted during February to March 2005 for the year 2004, in Jhikargacha Upazila in the district of Jessore, in Bangladesh. In the study, 64 boro rice farmers (small: 30, medium: 23 and large: 11) were randomly selected as respondents, from two villages, namely Barbakpur and Bodhkhana. The objectives of this study are to investigate the returns of boro rice farmers, considering their selling period, on the basis of farmers` category. The net returns of the farmers for a given period were not widely varied, irrespective of the categories of farmers and irrespective of middlemen as well. The net returns for the farmer varied according to the selling period, whether it was sold immediately after harvesting or during the lean period. The study found that although farmers in the area know that the selling of rice immediately after harvesting reduces their returns, but they, especially small and medium farmers, cannot hold back from this type of practice. The reason for selling the rice immediately after harvesting was not only a marketing problem but also the economic problems of the farmers.
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