The changing landscape of mangroves in Bangladesh compared to four other countries in tropical regions     

S. M. Mijan Uddin  A. T. M. Rafiqul Hoque  Saiful Arif Abdullah 《林业研究》2014,25(3):605-611

Loss of mangroves and consequent habitat fragmentation is a major concern throughout the world's tropical countries. Conversion of mangrove habitat due to aquaculture, agriculture, urbanization and industrialization, ecotourism, overlapping bureaucracy and conflicting policies is occurring at a striking rate. This paper reviews the trends of mangrove area changes in Bangladesh and compares them with four other countries in tropical regions that have significant mangrove areas. The rate of mangrove loss from the 1980 to 2005 was calculated using the compound interest rate formula for its explicit biological implication. In Bangladesh, the area of mangroves was found to have increased due to its higher accretion rate. In India the rate of mangrove loss had fallen. The rate of mangrove loss in Malaysia in the 1990s(-0.008 ha·a-1) was higher than the 1980s(-0.004 ha·a-1). In Indonesia, the rate decreased, from the 1980s(-0.018 ha·a-1) to the 1990s(-0.010 ha·a-1). Finally in Myanmar the rate of mangrove loss gradually accelerated. Aquaculture was found to be the common cause of mangrove conversion in the regions. Loss of mangroves is now a prominent global issue, associated with the loss of biodiversity, deterioration of habitat integrity, climatic changes, the amount of carbon sequestration, and resulting sea-level rise. Therefore, a systematic evaluation of these environmental impacts is prerequisite to realize sustainable mangrove management.  相似文献   

The potential of precision surface irrigation in the Indus Basin Irrigation System     

Arif A. Anwar  Waqas Ahmad  Muhammad Tousif Bhatti  Zia Ul Haq 《Irrigation Science》2016,34(5):379-396

In this research we explore the potential of precision surface irrigation to improve irrigation performance under the warabandi system prevalent in the Indus Basin Irrigation System. Data on field dimensions, field slopes along with characteristic soil infiltration properties and outlet discharge were collected through a survey of a sample tertiary unit of Maira Branch Canal, Khyber Pakhtunkhwa Province, Pakistan. The performance of all fields in the tertiary unit was analysed and reported in aggregate, with detailed results of one field presented for illustration. The objective is to determine the optimum field layout, defined as the number of border strips, for the observed field characteristics to maximize performance. The results indicate that performance improvement is relatively easily achievable through changes in field layout within current irrigation services. Estimated application efficiency is sensitive to the selected depth of application, and it is important that a practical depth of application is selected. We recommend a depth of application of 50 mm and show how this is achievable and leads to a low quarter distribution uniformity of 0.750 and an application efficiency of 80 %. We also explore the feasibility of a 10-day warabandi rather than the 7-day warabandi and show that there is no significant change in the performance under a 10-day warabandi.  相似文献   

EFFECT OF NITROGEN AND SULFUR FERTILIZATION ON YIELD COMPONENTS,SEED AND OIL YIELDS OF CANOLA     

Gulzar Ahmad  Amanullah Jan  Muhammad Arif  Mohammad Tariq Jan  H. Shah 《Journal of plant nutrition》2013,36(14):2069-2082

Field experiments were conducted to evaluate the effects of nitrogen (N) and sulfur (S) levels and their methods of application on canola. Branches plant^?1, pods plant^?1 and biological yield significantly increased with increase in nitrogen level and no significant increase in seed pod^?1 and seed and oil yields occurred beyond 120 kg N ha^?1. However, thousand seed weight consistently decreased with increasing level of nitrogen. Pods plant^?1 and biological yield continually increased with increase in sulfur level. Alternatively, significant increase in branches plant^?1, seed pod^?1, seed weight, seed and oil yields was noted with increase in sulfur level up to 40 kg ha^?1. Applications of sulfur and nitrogen in split significantly decreased seed yield as compared to sole applications. It is concluded that sulfur and nitrogen application as sole at the rate of 40 and 120 kg ha^?1, respectively performed better than the rest of their levels and method of application.  相似文献   

Urban wastewater irrigation and its effect on growth,photosynthesis and yield of chickpea under different doses of potassium     

Hamid I. Tak  Olubukola O. Babalola  Maria H. Huyser  Arif Inam 《Soil Science and Plant Nutrition》2013,59(2):156-167

The deficiency of potassium (K) has resulted in decreasing the yield and quality of food grains. Moreover, with decreasing water resources the use of wastewater in agriculture as an alternative source of water and nutrients is being debated. This study was therefore undertaken to test wastewater for its suitability as irrigation water together with uniform basal doses of nitrogen (N) and phosphorus (P) and varying doses of potassium (K_0, K₂₀, K₄₀ and K₆₀). It was observed that the plants receiving wastewater as a source of irrigation water performed better with a lower K dose. Potassium at 20?kg?ha^?1 along with wastewater resulted in better growth, photosynthetic rate (P _N), stomatal conductance (g _s) and yield of the chickpea (Cicer arietinum L.). Thus fertilizer rates could be lowered with the use of wastewater which can serve not only as the source of water but of nutrients also. However, regular monitoring of wastewater and soil for any buildup of heavy metal is necessary. The physical and chemical parameters of wastewater were also tested and most of them were found to be well within the permissible limits as set by the Food and Agriculture Organization (FAO).  相似文献   

Screening of Potato Cultivars to <Emphasis Type="Italic">Potato Mop-Top Virus</Emphasis> in Northwestern Pakistan     

Muhammad Arif  Ghazala Ruby  Anayatur Rehman  Murad Ali  Shamsur Rehman 《Potato Research》2016,59(4):295-312

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Dynamics of resistance to organophosphate and carbamate insecticides in the cotton whitefly <Emphasis Type="Italic">Bemisia tabaci</Emphasis> (Hemiptera: Aleyrodidae) from Pakistan     

Mushtaq Ahmad  M. Iqbal Arif  Muhammad Naveed 《Journal of pest science》2010,83(4):409-420

Field populations of adult whiteflies, Bemisia tabaci, from Pakistan were monitored from 1992 to 2007 for their susceptibility to seven organophosphate and three carbamate insecticides using a leaf-dip method. Malathion, quinalphos and chlorpyrifos generally exhibited no or a very low level of resistance in B. tabaci over a 16-year monitoring period. Resistance to profenofos, triazophos, parathion-methyl and ethion was usually low to high up to 1995, and then it dropped to very low levels during 1996–2004. Resistance levels again picked up from low to moderate levels for triazophos during 2005–2007, for parathion-methyl during 2003–2007, and for ethion in 2006. Among carbamates, thiodicarb resistance was high during 1994–1996, which dropped to moderate levels in 1997 and 1998 and to very low levels during 1999–2001, but again increased from low to high levels during 2002–2007. Methomyl resistance was moderate in 1994 and 1995, which dropped to very low levels during 1996–2002, and then increased to low levels during 2003–2007. Butocarboxim resistance remained very low during 1994–2003 and then increased from low to high levels during 2004–2007. The insecticides exhibiting no, very low or low resistance, and no cross-resistance among themselves can be exploited in devising an insecticide resistance management strategy to combat whitefly resistance in the field.  相似文献   

Determination of Residual and Cumulative Boron Requirements for Cotton and Wheat Crops Grown Under Calcareous Soil Conditions     

Niaz Ahmed  Muhammad Abid  Ghulam Mustafa  M. Arif Ali  Sagheer Ahmad 《Communications in Soil Science and Plant Analysis》2018,49(9):1092-1098

A two-year field experiment was conducted to elucidate the residual and cumulative boron (B) requirements for cotton and wheat crops. For the first time, cotton was sown in randomized complete blocks those received 0.0, 1.0, 1.5, 2.0, 2.5 and 3.0 kg B ha^?1 as borax (Na₂B₄O₇.10H₂0). Later, each plot was divided into two subplots for successive wheat and cotton crops and half of the pots received B at similar rates. Our results revealed that direct application of B at the rate of 2 and 2.5 kg ha^?1 produced optimum cotton yield during 2005. The same rates of B were consistent in residual plots but not in cumulative plots for both of the crops in successive years. It was thus concluded that soil applied B at the rate of 2.0 and 2.5 kg ha^?1 had significant residual effects on cotton and wheat yields.  相似文献   

Optimizing rice paddies’ lower greenhouse gas emissions and higher yield with SRI management under varying water table levels     

Hasanah  Nur Aini Iswati  Setiawan  Budi Indra  Arif  Chusnul  Widodo  Slamet  Uphoff  Norman 《Paddy and Water Environment》2019,17(3):485-495

Paddy and Water Environment - The System of Rice Intensification (SRI) is known as a climate-smart agricultural practice that increases rice production by changing the management of plants, soil,...  相似文献   

Germplasm conservation and quantitative estimation of podophyllotoxin and related glycosides of Podophyllum hexandrum     

Phalisteen Sultan  A. S. Shawl  Arif Jan  B. Hamid  H. Irshad 《Journal of Crop Science and Biotechnology》2009,12(4):267-274

We have done comparative morphological and chemotaxonomic studies to investigate the phylogenetic relationship of different accessions within the Podophyllum species. HPLC profiles revealed that all Podophyllum hexandrum accessions collected from different geographical locations are chemically highly diverse. Also, we have observed that chemotaxonomic studies clearly demonstrated that chemical characters of the Podophyllum hexandrum are suitable to generate essentially the same relationship as revealed by RAPD analysis.  相似文献   

Trend of within-plot selection practiced in two seedling seed orchards ofAcacia mangium in Indonesia     

Arif Nirsatmanto  Susumu Kurinobu 《Journal of Forest Research》2002,7(1):49-52

A trend of within-plot selection was examined by applying a retrospective selection index to the results of the selection in two seedling seed orchards ofA. mangium at South Kalimantan in Indonesia. The orchards were established in randomized complete block design with ten replications of four tree row plots. Within-plot selections were conducted twice with around 50% of selection intensity in those orchards: at 22 months and at 51 months after planting, then the results were analyzed with the data on volume, stem form and bole length measured before each selection. Bole length was found to be the highest priority trait throughout the two stages of selection in both orchards. Growth expressed by volume was also an important criterion at the first within-plot selection, while the priority was not obvious at the second selection. Expected gains by within-plot selection were generally small, although predicted gains were positive on all of the three traits at each stage of selection. The seedling seed orchards analyzed in this study were established under a technical cooperation project between JICA (Japan International Cooperation Agency) and Ministry of Forestry in Indonesia in collaboration with Inhutani 3.  相似文献