The DIAD beamline for Dual Imaging and Diffraction at Diamond Light Source has opted to use an in... more The DIAD beamline for Dual Imaging and Diffraction at Diamond Light Source has opted to use an industrial robot to position its Dectris Pilatus 2M CdTe diffraction detector. This setup was chosen to enable flexible positioning of the detector in a quarter-sphere around the sample position whilst reliably holding the large weight of 139 kg of detector, detector mount and cabling in a stable position. Metrology measurements showed that the detector can be positioned with a linear repeatability of <19.7 µm and a rotational repeatability of <16.3 µrad. The detector position stays stable for a 12 h period with <10.1 µm of movement for linear displacement and <3.8 µrad for rotational displacement. X-ray diffraction from calibration samples confirmed that the robot is sufficiently stable to resolve lattice d-spacings within the instrumental broadening given by detector position and beam divergence.
Dry direct-seeded rice (Oryza sativa L.), a climate-smart and resource-efficient (labor and water... more Dry direct-seeded rice (Oryza sativa L.), a climate-smart and resource-efficient (labor and water) rice production technology is gaining popularity in many parts of Asian countries; however, weeds are the major constraints for its early establishment and optimum productivity. Chemical weed management is effective, rapid, and also decreases weed management costs in dry direct-seeded rice (DSR) system; however, chemical use for weed management have a negative effect on the environment and also have human health hazards. Therefore, integrated weed management (IWM) is the best option for the sustainability of rice production under the DSR system. Improving competitiveness against weeds, weed-competitive rice cultivars, and high seeding rates were found to be the most promising IWM strategies in DSR. In this context, a field study was conducted to evaluate the weed competitiveness of rice cultivars and seeding rates on the performance of aus rice in dry direct-seeded systems in Banglades...
Very little is known about the changes that occur in soil organic carbon (SOC) and total nitrogen... more Very little is known about the changes that occur in soil organic carbon (SOC) and total nitrogen (TN) under an intensive rice-based cropping system following the change to minimal tillage and increased crop residue retention in the Gangetic Plains of South Asia. The field experiment was conducted for 3 years at Rajbari, Bangladesh to examine the impact of tillage practices and crop residue retention on carbon (C) and nitrogen (N) cycling. The experiment comprised four tillage practices—conventional tillage (CT), zero tillage (ZT), strip-tillage (ST), and bed planting (BP) in combination with two residue retention levels—increased residue (R50%) and low residue (R20%—the current practice). The TN, SOC, and mineral N (NH4+-N and NO3−-N) were measured in the soil at different crop growth stages. After 3 years, ZT, ST, and BP sequestered 12, 11, and 6% more SOC, and 18, 13, and 10% more TN, respectively than the conventional crop establishment practice at 0–5 cm soil depth. The accumul...
An experiment was conducted at Bangladesh Agricultural Research Institute (BARI), Gazipur during ... more An experiment was conducted at Bangladesh Agricultural Research Institute (BARI), Gazipur during November 2009 to May 2010 to study the growth, productivity and profitability of BRRI dhan28 cultivation as influenced by integrated crop and resources management. Puddled transplanted rice with farmers’ practices (Pd-TPRFP), puddled transplanted rice with integrated crop and resources management (Pd- TPR-ICRM) and reduced tillage unpuddled transplanted rice with ICRM (RT-UnPd- TPR-ICRM) practices were used as treatments. The numbers of tiller, leaf area index (LAI), chlorophyll index, root dry weight and total dry matter (TDM) production were significantly higher in the treatments having ICRM practices than with farmers’ practice. The Pd-TPR-ICRM and RT-UnPd-TPR-ICRM practices produced 6.68 t/ha and 6.54 t/ha grain yields, respectively, which were significantly higher than Pd-TPRFP (5.1 t/ha). The variable production cost in Pd-TPR-ICRM and RT-UnPd-TPRICRM practices were 20.52 and 17.98...
Dry-seeded rice systems are an emerging production technology in many Asian countries. A field st... more Dry-seeded rice systems are an emerging production technology in many Asian countries. A field study was conducted in 2011 and 2012 at the farm of the Rice Research and Development Institute, Batalagoda, Sri Lanka, to evaluate the performance of different herbicides in a dry-seeded rice system. Weed control treatments were nontreated (weedy), pretilachlor plus pyribenzoxim, cyhalofop-butyl, thiobencarb plus propanil, propanil, and bispyribac-sodium plus metamifop. All these POST herbicides were applied at 8 d after sowing, followed by an MCPA spray at 20 d after sowing. The dominant weeds in the study were barnyardgrass, Chinese sprangletop, and knotgrass. All herbicide treatments provided similar weed control, which ranged from 82 to 99%. Weeds in the nontreated plots reduced rice grain yield by 58 to 79% compared with the herbicide-treated plots. All herbicide-treated plots, except cyhalofop-butyl-treated ones, produced similar grain yield, which ranged from 3.7 to 4.2 t ha−1 in 2...
Bangladesh is a developing country whose poverty level decreased from 70% to 40% since 1970 to 20... more Bangladesh is a developing country whose poverty level decreased from 70% to 40% since 1970 to 2000. Almost 1% per year of the population went down to poverty level due to industrialization and higher agricultural production rate for green revolution and ...
The DIAD beamline for Dual Imaging and Diffraction at Diamond Light Source has opted to use an in... more The DIAD beamline for Dual Imaging and Diffraction at Diamond Light Source has opted to use an industrial robot to position its Dectris Pilatus 2M CdTe diffraction detector. This setup was chosen to enable flexible positioning of the detector in a quarter-sphere around the sample position whilst reliably holding the large weight of 139 kg of detector, detector mount and cabling in a stable position. Metrology measurements showed that the detector can be positioned with a linear repeatability of <19.7 µm and a rotational repeatability of <16.3 µrad. The detector position stays stable for a 12 h period with <10.1 µm of movement for linear displacement and <3.8 µrad for rotational displacement. X-ray diffraction from calibration samples confirmed that the robot is sufficiently stable to resolve lattice d-spacings within the instrumental broadening given by detector position and beam divergence.
Dry direct-seeded rice (Oryza sativa L.), a climate-smart and resource-efficient (labor and water... more Dry direct-seeded rice (Oryza sativa L.), a climate-smart and resource-efficient (labor and water) rice production technology is gaining popularity in many parts of Asian countries; however, weeds are the major constraints for its early establishment and optimum productivity. Chemical weed management is effective, rapid, and also decreases weed management costs in dry direct-seeded rice (DSR) system; however, chemical use for weed management have a negative effect on the environment and also have human health hazards. Therefore, integrated weed management (IWM) is the best option for the sustainability of rice production under the DSR system. Improving competitiveness against weeds, weed-competitive rice cultivars, and high seeding rates were found to be the most promising IWM strategies in DSR. In this context, a field study was conducted to evaluate the weed competitiveness of rice cultivars and seeding rates on the performance of aus rice in dry direct-seeded systems in Banglades...
Very little is known about the changes that occur in soil organic carbon (SOC) and total nitrogen... more Very little is known about the changes that occur in soil organic carbon (SOC) and total nitrogen (TN) under an intensive rice-based cropping system following the change to minimal tillage and increased crop residue retention in the Gangetic Plains of South Asia. The field experiment was conducted for 3 years at Rajbari, Bangladesh to examine the impact of tillage practices and crop residue retention on carbon (C) and nitrogen (N) cycling. The experiment comprised four tillage practices—conventional tillage (CT), zero tillage (ZT), strip-tillage (ST), and bed planting (BP) in combination with two residue retention levels—increased residue (R50%) and low residue (R20%—the current practice). The TN, SOC, and mineral N (NH4+-N and NO3−-N) were measured in the soil at different crop growth stages. After 3 years, ZT, ST, and BP sequestered 12, 11, and 6% more SOC, and 18, 13, and 10% more TN, respectively than the conventional crop establishment practice at 0–5 cm soil depth. The accumul...
An experiment was conducted at Bangladesh Agricultural Research Institute (BARI), Gazipur during ... more An experiment was conducted at Bangladesh Agricultural Research Institute (BARI), Gazipur during November 2009 to May 2010 to study the growth, productivity and profitability of BRRI dhan28 cultivation as influenced by integrated crop and resources management. Puddled transplanted rice with farmers’ practices (Pd-TPRFP), puddled transplanted rice with integrated crop and resources management (Pd- TPR-ICRM) and reduced tillage unpuddled transplanted rice with ICRM (RT-UnPd- TPR-ICRM) practices were used as treatments. The numbers of tiller, leaf area index (LAI), chlorophyll index, root dry weight and total dry matter (TDM) production were significantly higher in the treatments having ICRM practices than with farmers’ practice. The Pd-TPR-ICRM and RT-UnPd-TPR-ICRM practices produced 6.68 t/ha and 6.54 t/ha grain yields, respectively, which were significantly higher than Pd-TPRFP (5.1 t/ha). The variable production cost in Pd-TPR-ICRM and RT-UnPd-TPRICRM practices were 20.52 and 17.98...
Dry-seeded rice systems are an emerging production technology in many Asian countries. A field st... more Dry-seeded rice systems are an emerging production technology in many Asian countries. A field study was conducted in 2011 and 2012 at the farm of the Rice Research and Development Institute, Batalagoda, Sri Lanka, to evaluate the performance of different herbicides in a dry-seeded rice system. Weed control treatments were nontreated (weedy), pretilachlor plus pyribenzoxim, cyhalofop-butyl, thiobencarb plus propanil, propanil, and bispyribac-sodium plus metamifop. All these POST herbicides were applied at 8 d after sowing, followed by an MCPA spray at 20 d after sowing. The dominant weeds in the study were barnyardgrass, Chinese sprangletop, and knotgrass. All herbicide treatments provided similar weed control, which ranged from 82 to 99%. Weeds in the nontreated plots reduced rice grain yield by 58 to 79% compared with the herbicide-treated plots. All herbicide-treated plots, except cyhalofop-butyl-treated ones, produced similar grain yield, which ranged from 3.7 to 4.2 t ha−1 in 2...
Bangladesh is a developing country whose poverty level decreased from 70% to 40% since 1970 to 20... more Bangladesh is a developing country whose poverty level decreased from 70% to 40% since 1970 to 2000. Almost 1% per year of the population went down to poverty level due to industrialization and higher agricultural production rate for green revolution and ...
Uploads
Papers by Sharif Ahmed