Bangladesh enjoys food self-sufficiency or deficiency depending on crop damages by drought, floods, cyclones, storm/tidal surges and other natural hazards. Data on climate extremes were collected from literatures. Lan...Bangladesh enjoys food self-sufficiency or deficiency depending on crop damages by drought, floods, cyclones, storm/tidal surges and other natural hazards. Data on climate extremes were collected from literatures. Landsat images were analyzed for water availability. Arithmetic, geometric and weighted means were calculated for community vulnerability delineation using IDRISI3.2. About 12.64% populations live in disaster prone areas and their sensitivity to exposed hazards depends on financial capabilities. Crop area damages by natural hazards were the highest in Dhaka division followed by Rajshahi division during 2009-2014. The highest economic loss ($613 million) was found in Barisal division followed by Dhaka ($198.7 million) division. Flooding was the most damaging climate extreme followed by drought and hailstorm. Rice crops are frequently exposed to climate extremes and caused economic loss of $228 million during 2009-2014. Economic losses were <$110 to 1,000 ha-1 because of wheat/maize areas damaged by natural hazards. The most vulnerable areas are situated in the south-west and north-west part of the country. The most affected areas (35.4% of the country) had economic losses of $940-1,170 ha-1. About 2-4.7 million households (HH) were affected by different natural hazards in different regions of the country. Flood affected HHs were predominant in northern and north-east regions of the country. Common adaptations to natural hazard exposures are crop switching and migration. The other adaptation options could be improvement of post disaster recovery efficiency through financial support, supplying seeds and other inputs based on seasonal suitability.展开更多
Acid sulfate soils are normally not suitable for crop production unless they are appropriately ameliorated. An experiment was conducted in a glasshouse to enhance the growth of rice, variety MR219, planted on an acid ...Acid sulfate soils are normally not suitable for crop production unless they are appropriately ameliorated. An experiment was conducted in a glasshouse to enhance the growth of rice, variety MR219, planted on an acid sulfate soil using various soil amendments.The soil was collected from Semerak, Kelantan, Malaysia. Ground magnesium limestone(GML), bio-fertilizer, and basalt(each 4t ha-1) were added either alone or in combinations into the soil in pots 15 d before transplanting. Nitrogen, P and potash were applied at 150, 30, and 60 kg ha-1, respectively. Three seven-day-old rice seedlings were transplanted into each pot. The soil had a p H of 3.8 and contained organic C of 21 g kg-1, N of 1.2 g kg-1, available P of 192 mg kg-1, exchangeable K of 0.05 cmol c kg-1,and exchangeable Al of 4.30 cmol c kg-1, with low amounts of exchangeable Ca and Mg(0.60 and 0.70 cmol c kg-1). Bio-fertilizer treatment in combination with GML resulted in the highest p H of 5.4. The presence of high Al or Fe concentrations in the control soil without amendment severely affected the growth of rice. At 60 d of growth, higher plant heights, tiller numbers and leaf chlorophyll contents were obtained when the bio-fertilizer was applied individually or in combination with GML compared to the control. The presence of beneficial bacteria in bio-fertilizer might produce phytohormones and organic acids that could enhance plant growth and subsequently increase nutrient uptake by rice. Hence, it can be concluded that addition of bio-fertilizer and GML improved rice growth by increasing soil p H which consequently eliminated Al and/or Fe toxicity prevalent in the acid sulfate soil.展开更多
文摘Bangladesh enjoys food self-sufficiency or deficiency depending on crop damages by drought, floods, cyclones, storm/tidal surges and other natural hazards. Data on climate extremes were collected from literatures. Landsat images were analyzed for water availability. Arithmetic, geometric and weighted means were calculated for community vulnerability delineation using IDRISI3.2. About 12.64% populations live in disaster prone areas and their sensitivity to exposed hazards depends on financial capabilities. Crop area damages by natural hazards were the highest in Dhaka division followed by Rajshahi division during 2009-2014. The highest economic loss ($613 million) was found in Barisal division followed by Dhaka ($198.7 million) division. Flooding was the most damaging climate extreme followed by drought and hailstorm. Rice crops are frequently exposed to climate extremes and caused economic loss of $228 million during 2009-2014. Economic losses were <$110 to 1,000 ha-1 because of wheat/maize areas damaged by natural hazards. The most vulnerable areas are situated in the south-west and north-west part of the country. The most affected areas (35.4% of the country) had economic losses of $940-1,170 ha-1. About 2-4.7 million households (HH) were affected by different natural hazards in different regions of the country. Flood affected HHs were predominant in northern and north-east regions of the country. Common adaptations to natural hazard exposures are crop switching and migration. The other adaptation options could be improvement of post disaster recovery efficiency through financial support, supplying seeds and other inputs based on seasonal suitability.
基金Supported by the Long-Term Research Grant Scheme(LRGS)Fund for Food Security from Ministry of Education,Malaysia(No.UPM/700-1/3/LRGS)
文摘Acid sulfate soils are normally not suitable for crop production unless they are appropriately ameliorated. An experiment was conducted in a glasshouse to enhance the growth of rice, variety MR219, planted on an acid sulfate soil using various soil amendments.The soil was collected from Semerak, Kelantan, Malaysia. Ground magnesium limestone(GML), bio-fertilizer, and basalt(each 4t ha-1) were added either alone or in combinations into the soil in pots 15 d before transplanting. Nitrogen, P and potash were applied at 150, 30, and 60 kg ha-1, respectively. Three seven-day-old rice seedlings were transplanted into each pot. The soil had a p H of 3.8 and contained organic C of 21 g kg-1, N of 1.2 g kg-1, available P of 192 mg kg-1, exchangeable K of 0.05 cmol c kg-1,and exchangeable Al of 4.30 cmol c kg-1, with low amounts of exchangeable Ca and Mg(0.60 and 0.70 cmol c kg-1). Bio-fertilizer treatment in combination with GML resulted in the highest p H of 5.4. The presence of high Al or Fe concentrations in the control soil without amendment severely affected the growth of rice. At 60 d of growth, higher plant heights, tiller numbers and leaf chlorophyll contents were obtained when the bio-fertilizer was applied individually or in combination with GML compared to the control. The presence of beneficial bacteria in bio-fertilizer might produce phytohormones and organic acids that could enhance plant growth and subsequently increase nutrient uptake by rice. Hence, it can be concluded that addition of bio-fertilizer and GML improved rice growth by increasing soil p H which consequently eliminated Al and/or Fe toxicity prevalent in the acid sulfate soil.
