A study on utilization of irrigation water in rice field, water saving techniques like shallow application of water and irrigating after 3 days of disappearing of standing water should be followed properly. Such a practice is economically more beneficial than the traditional practice of continuous standing water.
A study was conducted to validate CEGIS-developed drought assessment (DRAS) model for the prediction of net irrigation requirement (NIR) for rice. It was observed that the DRAS model predicted relatively optimum NIR for rice cultivation in Boro season in various water regimes imposed in the field for rice cultivation. Although the model predicted NIR was slightly higher than BRRI recommended water management practice for rice in Boro season, it seems to provide water requirements for rice with sufficient accuracy.
A check valve was developed, which can reduce the drudgery of farmers for starting the STW through overcoming the priming problem and also facilitate the pipe distribution system in STW area.
A drought simulation model (DSM) has been developed which can simulate drought severity, drought amount and duration, for rice crop by using daily water balance. This model is also able to prepare irrigation schedule of rice. In drought prone areas of Bangladesh, particularly in Barind areas, DSM study showed that from the point of risk of drought, a short duration rice variety are at low, medium and high risk when it is transplanted during 15 June-25 July, 26 July-5 August and 6 - 15 August, respectively. Again a medium duration rice variety are at low, medium and high risk when it is transplanted during 15 June-5 July, 6 - 25 July and 26 July-15 August, respectively and for a long duration variety, 15 - 25 June, 26 June-15 July and 16 July-15 August, transplanting are at low, medium and high risk, respectively.
Studies were conducted to explore possibilities of coastal water resources utilization for improving productivity of the coastal regions of Bangladesh. It was observed that soil and river water salinity remained below 4 dS/m and 1 dS/m, respectively at Kismat Fultala village under Batiaghata Upazila of Khulna district throughout the growing season of T. Aman rice. Although soil salinity increased in Boro season, river water salinity permits rice irrigation from mid-November to mid-February. Ground water salinity was higher in Batiaghata and was unsuitable for rice irrigation. In Tala area it remained below 3.0 dS/m throught the year and some farmers were utilizing ground water for rice cultivation in the dry season.
Studies were conducted to achieve higher productivity of the coastal ricelands by maximizing rainwater utilization in Aus season. Two BRRI varieties were grown under direct dry sowing and transplanting method in rainfed condition. Rainfall was sufficient to meet up the crop water requirement for rice. It was observed that there was no yield difference between the methods of cultivating Aus rice. Water use efficiency was higher in line sowing method of rice cultivation, where as higher water productivity was recorded in transplanting method under rainfed environment
The traditional cropping practice of the Batiaghata upazila in Khulna district, situated in the southwest part of the coastal region, is Fallow-Local Rice-Fallow. An innovative water management and cropping approach was established for improving productivity of the coastal region. BRRI developed 7 HYV rice were grown under rainfed condition with 15 to 20 cm levees around plots. Rainfall was sufficient to meet-up crop water requirement for rice, yet participatory farmers provided supplemental irrigation from the Kazibachha river during neap tide to facilitate growth and development of MV rice. Yields of aromatic MV rice were about 4.0 t/ha and for non-aromatic rice it varied between 5.0 to 6.0 t/ha, which was at least 2 times higher than traditional rice yield. Therefore MV rice, whether salt-tolerant or not, can be grown successfully in T Aman season by utilizing rainwater to increase productivity of the coastal regions.
As part of the innovative water management and cropping approach to improve productivity of the coastal region, BRRI dhan28 was grown during mid-November to mid-April by managing salinity of the river water. River water salinity remained <4.0 dS/m from mid-November to mid-February and was used to irrigate rice during neap tide directly from the river through sluice and/or flash gates. After that river water was conserved in the natural canals through sluice gate during early February for irrigating rice at the later part of the growing season, from mid-February to end of March. Average yield of BRRI dhan28 was about 4.0 t/ha.
Groundwater table fluctuation was monitored at the selected BRRI stations. During 2005-06 periods, maximum lowering of groundwater level was observed in March/April, which were 18.92, 9.37, 9.10, 7.32, 5.40, 4.89 and 4.88 m at Gazipur, Rajshahi, Comilla, Hobiganj, Bhanga, Rangpur and Sonagazi area, respectively. Minimum water table depths were 12.97, 2.20, 2.06, 3.96, 2.28, 1.40 and 0.95 m below the ground surface at the above mentioned stations, respectively, which was observed during September/October.
The groundwater in the Barind area had no salinity problem. On the basis of SAR, SSP and RSC values it was found that they will cause no adverse effect on soil permeability. Based on iron, sodium (SAR), chloride, boron and zinc contents, in the irrigation water, there had been no toxicity problem in these areas. Therefore, the pumped groundwater was suitable for irrigation purposes in the Barind area. It was found that there was no arsenic content in the collected samples and therefore, the groundwater used for irrigation in the study area is free from arsenic pollution. But quality of irrigation water should be monitored periodically.

In T. Aman, the advanced lines BR6592-4-6-4 and BR6592-4-6-5 produced grain yield of 4.3 t/ha which was about 8% higher than that of BR11 but about 5% lower than that of Swarna. Considering grain yield, growth duration, grain size, lodging resistance and disease tolerance, the advanced lines BR6592-4-6-4 and BR6592-4-6-5 appeared to be good. Premium Quality Rice (PQR) advanced lines gave very similar yields of 5.5-6.0 t/ha with almost similar growth durations (152-156 days). Four lines (PQR-4, 5, 6 and 7) had dwarf plant type (plant height 75-77 cm) having small grain size (1000 grain weight about 18 g). Considering grain size and yield performance, PQR-4 and 6 might be included in PVT.
In T. Aman, Direct-Wet-Seeded Rice (DWSR) using drum seeder was demonstrated in 17 farmers' fields in 17 Upazillas. BRRI dhan30, BRRI dhan31, BRRI dhan32, BRRI dhan33, BRRI dhan39, BRRI dhan40 and BRRI dhan41 produced about 10% higher grain yield when grown as DWSR than Transplanted Rice (TPR). Growth duration was reduced by 6 to 21 days in DWSR than TPR depending on varieties and locations. In Boro, DWSR was demonstrated in 29 farmers' fields under 27 Upazillas. On an average, DWSR yielded about 10 % higher than TPR and matured about 10 days earlier than TPR. Most farmers agreed about the low cost, early maturity and higher yields of DWSR. However, the farmers were also able to identify severe weed infestation, unavailability of irrigation as the major constraints to the adoption of this technology.
Leaf Colour Chart (LCC) was validated and upscaled through out the country during T. Aman and Boro, 2006 seasons. On an average LCC saved urea of about 40 kg/ha which was equivalent to about Tk. 260/ha. LCC also helped to increase yield and reduce pest pressure to some extent. On an average LCC based urea application gave about 8% higher grain yield over farmers' managed urea application. About 500 LCC were distributed among farmers, DAE and NGO extension workers.
Poultry manures have potentials to replace the chemical P fertilizers for low land rice culture in P deficient soils. Applied poultry manure at 2 t/ha gave significantly higher grain yield (5.43 t/ha) than P10 (4.61 t/ha) and P20 (4.90 t/ha).
For effective use of rainfall and maximizing the T. Aman yield, demonstrations of improved water conservation were conducted in 3 farmers’ field of Kapasia, Gazipur. By maintaining 15 cm levee, more rainwater was preserved in rice field. Irrigation through plastic pipe required about 1620 mm water in 33 decimal plot, whereas that through earthen canal was about 2250 mm. Moreover, irrigation time for the same area was 26 hrs. and 48 hrs., respectively in plastic pipe and earthen canal. About 28% conveyance water and about 46% time could be saved in the farmers field, which reduce the irrigation cost significantly.
Seed health technique for quality seed production was demonstrated in 5 farmers plots in Sreepur upazila of Gazipur. A total of 214 kg quality and healthy seeds of BR11 was produced following intensive roughing of offtypes and diseased plants, which was preserved by them for the next year rice production. In Jhum system, during Aus season BR24, 26 and BRRI dhan27 were found well adapted and they produced nearly double yields than those of the locally adopted rice varieties and gaining popularity in Jhum system in the hill areas.
During T. Aman, 2005, Seed Production and Dissemination Programme (SPDP) was conducted in 43 locations of - districts with the varieties- BR11, BR22, BRRI dhan30, 31, 32, 33, 34, 37, 38, 39, 40 and 41. Out of a total produced 28 tons seeds, farmers retained about 7 tons of seeds for further propagation. During Boro, 2006, SPDP was conducted in 28 locations of 25 districts with the varieties BRRI dhan28, BRRI dhan29 and BRRI dhan36. BRRI dhan29 gave the highest yield of about 6.41 t/ha while BRRI dhan28 yielded 5.26 t/ha. BRRI dhan36 yielded about 5.82 t/ha. Out of a total produced 50 tons the farmers retained about 12 tons of seeds for further propagation or exchange among other farmers.
Twenty-three Rice Schools (one-day farmers training) (including some BARC funded trainings) were conducted in several districts. A total of 720 farmers and 80 SAAOs of DAE participated. Nine field days were conducted in 7 districts in which about 535 farmers, 25 SAAOs, 302 DAE/BRRI/NGO officers, scientists and other public representatives participated. The division played a very significant role in the development of the Bangladesh Rice Knoweledge Bank (BRKB), an electronic repository of rice technology knowledge.

The Training Division has conducted and coordinated a total of 44 training courses, including long and short courses. Duration of the courses varied from 1-day to 1-month according to their nature and demand. A total of 1283 participants from different government organizations, (NGOs), non-government organizations (NGOs) and farmers were trained through these courses. The highest number of participants (88.58%) was from the Department of Agricultural Extension (DAE). The overall improvement of knowledge through rice production training (RPT) was very high (237.68%) indicating, extension providers need RPT to develop their knowledge for improved rice production technologies. Feedback remarks on different aspects of the training courses and trainers performances were also collected through questionnaire to determine the effectiveness of imparted training. Result's indicate that most of the trainees gave positive views about the imparted course content, topic, and method of training, presentation style and usefulness of the training. However, participants of both the short and long courses mentioned that the duration of the courses was not enough for better understanding of all the modern knowledge and technologies of rice production activities. They suggested for increasing duration of the short and long course from 1 week to 2 weeks and 1 month to 2 months. The overall performances of BRRI's speakers ranged from good to very good.

Regional yield trial (RYT) of Aus 2005 showed that the line BR6987-65-11 yielded 4.86 t/ha, which was 22 and 17 percent greater than BR26 and BRRI dhan28, respectively. Eighteen BRRI developed varieties were tested in T. Aman under stability analysis. The highest grain yield was obtained from BR22 (6.38 t/ha) followed by BRRI dhan40 (5.80 t/ha). BR4, BR10, BR11, BR23, BR25, BRRI dhan32, BRRI dhan38 and BRRI dhan41 yielded 4.66 - 5.71 t/ha. Very poor yields of 1.45, 2.03 and 2.32 t/ha were obtained from BRRI dhan39, BRRI dhan33 and BR3, respectively.
Premium quality rice Basmoti 8 gave 6.55 t/ha at BRRI RS farm Charbadna; and Basmoti 6 and Basmati 7 gave 5.75 t/ha at farmer's field in Nalchhiti, Jhalakathi. Bacterial leaf blight was found as a major disease in the Aus, Aman and Boro seasons. BRRI dhan31 and BRRI dhan32 yielded 3.34 and 4.37 t/ha, respectively, with the soil inherent fertility under tidal flooded ecosystem. Application of N increased yield to 4.23 t/ha in case of BRRI dhan31, but there was no N response in BRRI dhan32.
Neither phosphorus nor potassium fertilizer application gave any yield advantage to the modern varieties in the T. Aman and Boro seasons.
Partial factor productivity (PFP) in BRRI dhan32 for N, P and K was 58, 402 and 102 kg/kg, respectively, which were slightly greater in BRRI dhan31.
In the Boro season, BRRI dhan29 produced 3.19 t/ha without no N fertilizer application, which was increased from 6.02 to 6.47 t/ha when N was applied. Omission of P or K did not decrease rice yield than that received complete NPK fertilizers. Nutrient absorption by BRRI dhan29 was the highest during 60-75 days after transplanting (DAT), when growth rate was also the highest. In the NPK applied plot, the average absorption rate of N, P and K was 3.30, 0.86 and 4.56 kg ha-1 d-1, respectively, during 60-75 DAT. Rice plant seems to loss some of their absorbed N after flowering.
Tidal sediment load in BRRI RS farm, Sagardi and Charbadna was 13.6 and 19.7 t/ha, respectively. Tidal sediment contained 1.98-2.99% organic matter, 28-33 ppm available phosphorus and 0.52-0.90 meq/100 g soil exchangeable potassium.
Salt injury in T. Aman rice was found at Patharghata, Borguna in Aman 2005. The soil salinity level was as high as 13.47 dS/m.
Sweet clover (Melilotus alba) a green manuring crop, was found to grow naturally at the BRRI RS farm, Sagardi. The plant contained 2.50% N, 0.20% P and 1.20% K.
In the advanced line adaptive research trial (ALART) in the Aman season 2005 at Babugonj, Barisal, farmers preferred BRRI dhan32, compared to three advanced lines BR6592-4-6-4, BR6592-4-6-5 and IR70175-54-1-1-2-3-HR2 due to shiny grain colour and comparatively lower disease and insect infestation in BRRI dhan32.
In the demonstration of maximum yield of the BRRI varieties, BR23 and BRRI dhan44 yielded 5.12 and 5.46 t/ha, respectively, in T. Aman season at Babuganj, Barisal. In Boro season, the yield of demonstration plot ranged 7.62 - 10.0 t/ha with an average of 8.94 0.70 t/ha, compared to the farmers' plots of 8.07 0.28 t/ha at Agailjhara, Barisal.
BRRI dhan29 yielded 6.61 0.45 t/ha when the crop was established through direct seeding by drum seeder compared to 6.44 0.35 t/ha obtained with the transplanting method. The growth duration of the direct seeding method was 135 5 days and that of transplanted method was 155 5 days. Growing degree-days in the direct-seeding method was observed 1835 88, compared to 2044 94 calories in transplanting method.

Sixty-seven entries from IRSSTN were tested under moderately saline soil (EC 4-8dS/m). Only two entries of IR67075-2B-2-2 and IR70870-B-P-2-2 were selected. Six crosses from F2, 5 crosses from F3 and 9 crosses from F4 were seeded. Out f which 63, 65 and 45 plants selected for further study. Evaluate salt tolerant 20 entries of which 4 entries were found promising. Two hundred progenies from 4 crosses, bulk progenies from 3 crosses, 213 progenies from 4 crosses were tested. Out of which 149, 152 and 196 progenies were selected. To develop a model for stability index of BRRI released Aman rice varieties were examined. The highest yield of 4.31 t/ha (BR25), 5 t/ha (BRRI dhan40) and 4.26 t/ha (BR22) were produced from early, medium and longer duration group, respectively.
Six Vietnamese rice varieties were tested against BR24 and locally popular Binnatoa under dry seeded and transplanted condition. Considering yield performance and early maturity, OM1490 and AS996 found promising. Four planting methods (broadcasting, line sowing, dibbling and ridge were examined. Dibbling and line sowing equally were effective for the coastal region of Bangladesh. Seven aromatic and fine rice's of BR5, BRRI dhan34, BRRI dhan37, BRRI dhan38, Kalizira, Kataribhog and Basmati 370 were tested under four dates of planting started from August 06 and continued up to September 21 with 5 days interval. All the varieties performed better yield when planted August 21. But Kalizira, Kataribhog gave constantly good yield even when planted in 05 September. Under direct wet seeding, we compared the growth rate of Rajasail and BRRI dhan41. The growth rate of Rajasail relatively higher than BRRI dhan41 (32% yield increase over control). BRRI dhan41 and Rajasail were examined under direct wet seeding using drum seeder in T. Aman. Drum seeder technology could be popularizing to save substantial cost of cultivation.
Salinity tolerance limit of BRRI dhan28 and BRRI dhan36 were tested. Both the varieties were survived at salinity level of 3-4 dS/m. At seedling stage, the salinity tolerance limit of BRRI dhan36 was 5-6 dS/m which was comparatively higher tolerance limit than BRRI dhan28. To compare the salinity level of fallow and grass pea covered land at 0-15 and 15-30cm depth of soil. The salinity gradually increased with time and thereafter slowly decreased. The salinity of fallow land relatively higher than grass pea covered land. Coastal saline land showed is under cropping to prevent capillary rice of salt molecules. Two ploughing methods (Country plough and power tiller) were tested against unploughed land. The salinity level of country ploughed land was lower than that of land ploughed by power tiller. Therefore, coastal saline land should be ploughed immediate after harvest of Aman rice to protect the rise of salt molecules upwards.
We have observe the probability of growing vegetables after harvest Aman rice to maximize the crop productivity in the coastal area of Bangladesh. Rainwater was stored in mini pond during monsoon season. The yield of tomato increased (54-56%) in irrigation applied plots from OFR1 and OFR2 than without irrigated plots.
Nine rice-rice based cropping patterns were tested to identify economically profitable, socially acceptable and environmentally sound enterprises for the farmers at coastal char land. Among the patterns, BRRI dhan27-BRRI dhan41-Lady's finger/Chilli found promising. Leafy vegetables (Lal shak, palong shak, mula shak, batishak, gima kalmi, puishak and winter vegetables of bottle gourd, sweet gourd, bean, carrot knolkhol, lady's finger were evaluated under 3.5-6.0 dS/m. Most of the vegetables were produced with good economic yield. In rice straw mulching experiment, one irrigation and rice straw mulching significantly increased the yield of tomato (56%) garlic (30%) and chilli (41%).
Recently, released BRRI dhan42 and BRRI dhan43 were conducted at BRRI farm. The yield produced by these varieties were 3.98 and 3.6 t/ha. These varieties were well adapted at char areas and the farmer's reaction was very much positive. Demos of MV rice's BR24, BRRI dhan27, BRRI dhan37, BRRI dhan38, BRRI dhan40 and BRRI dhan41 were conducted at different location of Noakhali-Laxmipur-Feni-Chittagong and Cox's Bazar. Farmer's reaction regarding these varieties was positive. Yield gap demonstrations of rice were jointly conducted with DAE. Lack of good quality seeds, used over aged seedling with delay planting and imbalanced fertilization were the main reasons for lower yield.