In this paper successive depletion of groundwater level with expansion of groundwater irrigation in Barind Tract has been discussed from mid 1960s to 2010 in the context of Tanore Upazila, which is located in severely...In this paper successive depletion of groundwater level with expansion of groundwater irrigation in Barind Tract has been discussed from mid 1960s to 2010 in the context of Tanore Upazila, which is located in severely drought prone area of northwest Bangladesh. After starting of groundwater irrigation in Bangladesh, it spread rapidly all over the country, and about 80% of agricultural land is now supplied irrigation from groundwater. Availability of irrigation in Barind Tract has revolutionized its agriculture, but groundwater level is successively falling all over the country due to excessive withdrawal, and this process is accelerating due to water withdrawal from major rivers by upstream countries. In northwestern part of Bangladesh groundwater depletion problem is severe because this part is free from seasonal flooding. Only source of recharging of groundwater aquifer in this area is rainfall, but rainfall is also lowest here among the country. In this context, this paper presents the change of groundwater level with the spreading of groundwater irrigation in Barind Tract. Hydrograph analysis, groundwater level mapping, groundwater depletion rate calculation are done from groundwater level observation well data of Bangladesh Water Development Board (BWDB) and Barind Multipurpose Development Authority (BMDA). Climatic condition is analyzed by calculation of rainfall deviation from the data of Bangladesh Meteorological Department (BMD). Focus Group Discussion (FGD) and interviews with farmers and experts of different branches are conducted to understand the nature of problems in the study area. Agricultural pattern, cropping intensity (262% in study area and national intensity is 180%), methods of cultivation, crop variety and yields all show a positive change after starting of groundwater irrigation in mid 1980s, but water level is continuously lowering at the rate of 1.37 ft/y in wet season and 0.72 ft/y in dry season. Water is the main input for agriculture but successive depletion of groundwater level can be a serious problem for water stressed Barind Tract. Crop diversification, artificial recharging, increasing dependency on surface water, increasing irrigation efficiency, rainwater harvesting etc., can be option for the area.展开更多
In this paper the lithological study and mapping of Barind Tract is done by using irrigation boreholes log data in the context of an upazila under Barind Tract in northwest Bangladesh. Northwestern part of Bangladesh ...In this paper the lithological study and mapping of Barind Tract is done by using irrigation boreholes log data in the context of an upazila under Barind Tract in northwest Bangladesh. Northwestern part of Bangladesh is severely drought prone area with lowest yearly rainfall in the country. Before groundwater irrigation only one crop was cultivated in this area in rainy season. After spreading of groundwater irrigation agriculture is flourished here, but groundwater level is severely going down, which is making this area risky for several adverse effect like land subsidence, biodiversity loss etc. Lithology is one of the important factors that affect the recharging of groundwater aquifer of any area. This research mainly based on secondary data. Irrigation boreholes log data are collected from Barind Multipurpose Development Authority (BMDA), a local authority under the Ministry of Agriculture of Bangladesh government provide irrigation in Barind Tract. A GPS survey is conducted to locate the boreholes in the study area. From the study highest thickness of clay layer found 90 ft and lowest 20 ft, and thickness gradually increase from eastern to western side. Aquifer is located between 20 - 90 ft depth from the surface and direction of aquifer is western to eastern side. Agriculture of study area is totally dependent on groundwater irrigation. Thick layer of clay impede recharging of groundwater table. Due to thick layer of sticky and plastic clay land subsidence risk is low, but it act as aquitard which impede groundwater recharging and increase surface runoff.展开更多
The aim of the present study was to evaluate the performance of Napier cultivars in terms of forage yield, plant morphology and nutrient contents under two different agro-ecology and geo-topographic conditions. Three ...The aim of the present study was to evaluate the performance of Napier cultivars in terms of forage yield, plant morphology and nutrient contents under two different agro-ecology and geo-topographic conditions. Three Napier cultivars being conserved by Bangladesh Livestock Research Institute (BLRI), namely-BLRI</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">Napier 1, (BN-1), BLRI</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">Napier 3 (BN-3) and Merkeron (BN-5) were selected to cultivate in severe drought prone areas (called Barind) and non-drought area at Savar (Modhupur terrace). Stem cuttings were planted in rows apart from 70 cm and 35cm spacing between plants. Data of 6 consecutive harvests from a period of approximately one year were collected and analyzed statistically by “R” software. The results showed that cultivar and location had </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">significant (P < 0.001) effect on biomass yield, plant height and leaf-stem ratio (LSR), while number of tillers </span><span style="font-family:Verdana;">were </span><span style="font-family:Verdana;">significantly varied with locations. BN-3 yielded the highest biomass (33.32 t/ha/harvest) at non-drought location (42.98 t/ha/harvest). The highest plant height was obtained in BN-1 (171.2 cm) at non-drought location (174.6 cm). Number of tiller</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> per hill ranged from 25.4 to 26.3 among cultivars (P > 0.05) and the highest tillers were found at non-drought location (28.1 no). The best LSR was estimated from BN-5 (0.86) at drought location (0.95). The proximate analysis showed that CP, ADF and NDF in whole plant </span><span style="font-family:Verdana;">were </span><span style="font-family:Verdana;">varied significantly (P < 0.001), being the highest contents in BN-1 (10.69%, 46.20% and 54.58%, respectively). On the other hand, DM and ash contents did not differ significantly (P > 0.05) among cultivars which ranged from 15.80% to 17.13% and 13.10% to 14.58%, respectively. The highest CP content in whole plant was obtained at non-drought location (11.89%), while the lowest ash (10.57%) and NDF (52.71%) contents were obtained at the same location. The highest CP contents in leaf were found at non-drought (15.03%) and the lowest ash (9.86%) at the same location. The highest CP contents (5.90%) in stem were found at non-drought location, while the lowest ash (11.28%) and NDF (54.59%) contents </span><span style="font-family:Verdana;">were obtained </span><span style="font-family:Verdana;">at the same location. Finally, the experiment reveals the superiority in biomass yield and nutritional quality (in</span><span style="font-family:""> </span><span style="font-family:Verdana;">terms of CP content) with the ranking orders of BN-3 > BN-1 > BN-5 and BN-1 > BN-3 > BN-5. Therefore, it may be concluded that BN-1, BN-3</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and BN-5 cultivars were well adapted in both drought and non-drought conditions, although performance showed better in later condition</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;">. However, in terms of forage yield and overall nutrient composition, the performance of BN-3 was the best irrespective of locations.展开更多
文摘In this paper successive depletion of groundwater level with expansion of groundwater irrigation in Barind Tract has been discussed from mid 1960s to 2010 in the context of Tanore Upazila, which is located in severely drought prone area of northwest Bangladesh. After starting of groundwater irrigation in Bangladesh, it spread rapidly all over the country, and about 80% of agricultural land is now supplied irrigation from groundwater. Availability of irrigation in Barind Tract has revolutionized its agriculture, but groundwater level is successively falling all over the country due to excessive withdrawal, and this process is accelerating due to water withdrawal from major rivers by upstream countries. In northwestern part of Bangladesh groundwater depletion problem is severe because this part is free from seasonal flooding. Only source of recharging of groundwater aquifer in this area is rainfall, but rainfall is also lowest here among the country. In this context, this paper presents the change of groundwater level with the spreading of groundwater irrigation in Barind Tract. Hydrograph analysis, groundwater level mapping, groundwater depletion rate calculation are done from groundwater level observation well data of Bangladesh Water Development Board (BWDB) and Barind Multipurpose Development Authority (BMDA). Climatic condition is analyzed by calculation of rainfall deviation from the data of Bangladesh Meteorological Department (BMD). Focus Group Discussion (FGD) and interviews with farmers and experts of different branches are conducted to understand the nature of problems in the study area. Agricultural pattern, cropping intensity (262% in study area and national intensity is 180%), methods of cultivation, crop variety and yields all show a positive change after starting of groundwater irrigation in mid 1980s, but water level is continuously lowering at the rate of 1.37 ft/y in wet season and 0.72 ft/y in dry season. Water is the main input for agriculture but successive depletion of groundwater level can be a serious problem for water stressed Barind Tract. Crop diversification, artificial recharging, increasing dependency on surface water, increasing irrigation efficiency, rainwater harvesting etc., can be option for the area.
文摘In this paper the lithological study and mapping of Barind Tract is done by using irrigation boreholes log data in the context of an upazila under Barind Tract in northwest Bangladesh. Northwestern part of Bangladesh is severely drought prone area with lowest yearly rainfall in the country. Before groundwater irrigation only one crop was cultivated in this area in rainy season. After spreading of groundwater irrigation agriculture is flourished here, but groundwater level is severely going down, which is making this area risky for several adverse effect like land subsidence, biodiversity loss etc. Lithology is one of the important factors that affect the recharging of groundwater aquifer of any area. This research mainly based on secondary data. Irrigation boreholes log data are collected from Barind Multipurpose Development Authority (BMDA), a local authority under the Ministry of Agriculture of Bangladesh government provide irrigation in Barind Tract. A GPS survey is conducted to locate the boreholes in the study area. From the study highest thickness of clay layer found 90 ft and lowest 20 ft, and thickness gradually increase from eastern to western side. Aquifer is located between 20 - 90 ft depth from the surface and direction of aquifer is western to eastern side. Agriculture of study area is totally dependent on groundwater irrigation. Thick layer of clay impede recharging of groundwater table. Due to thick layer of sticky and plastic clay land subsidence risk is low, but it act as aquitard which impede groundwater recharging and increase surface runoff.
文摘The aim of the present study was to evaluate the performance of Napier cultivars in terms of forage yield, plant morphology and nutrient contents under two different agro-ecology and geo-topographic conditions. Three Napier cultivars being conserved by Bangladesh Livestock Research Institute (BLRI), namely-BLRI</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">Napier 1, (BN-1), BLRI</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">Napier 3 (BN-3) and Merkeron (BN-5) were selected to cultivate in severe drought prone areas (called Barind) and non-drought area at Savar (Modhupur terrace). Stem cuttings were planted in rows apart from 70 cm and 35cm spacing between plants. Data of 6 consecutive harvests from a period of approximately one year were collected and analyzed statistically by “R” software. The results showed that cultivar and location had </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">significant (P < 0.001) effect on biomass yield, plant height and leaf-stem ratio (LSR), while number of tillers </span><span style="font-family:Verdana;">were </span><span style="font-family:Verdana;">significantly varied with locations. BN-3 yielded the highest biomass (33.32 t/ha/harvest) at non-drought location (42.98 t/ha/harvest). The highest plant height was obtained in BN-1 (171.2 cm) at non-drought location (174.6 cm). Number of tiller</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> per hill ranged from 25.4 to 26.3 among cultivars (P > 0.05) and the highest tillers were found at non-drought location (28.1 no). The best LSR was estimated from BN-5 (0.86) at drought location (0.95). The proximate analysis showed that CP, ADF and NDF in whole plant </span><span style="font-family:Verdana;">were </span><span style="font-family:Verdana;">varied significantly (P < 0.001), being the highest contents in BN-1 (10.69%, 46.20% and 54.58%, respectively). On the other hand, DM and ash contents did not differ significantly (P > 0.05) among cultivars which ranged from 15.80% to 17.13% and 13.10% to 14.58%, respectively. The highest CP content in whole plant was obtained at non-drought location (11.89%), while the lowest ash (10.57%) and NDF (52.71%) contents were obtained at the same location. The highest CP contents in leaf were found at non-drought (15.03%) and the lowest ash (9.86%) at the same location. The highest CP contents (5.90%) in stem were found at non-drought location, while the lowest ash (11.28%) and NDF (54.59%) contents </span><span style="font-family:Verdana;">were obtained </span><span style="font-family:Verdana;">at the same location. Finally, the experiment reveals the superiority in biomass yield and nutritional quality (in</span><span style="font-family:""> </span><span style="font-family:Verdana;">terms of CP content) with the ranking orders of BN-3 > BN-1 > BN-5 and BN-1 > BN-3 > BN-5. Therefore, it may be concluded that BN-1, BN-3</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and BN-5 cultivars were well adapted in both drought and non-drought conditions, although performance showed better in later condition</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;">. However, in terms of forage yield and overall nutrient composition, the performance of BN-3 was the best irrespective of locations.
