Growth, Yield and Mineral Composition of Three Rice Varieties Cultivated under Salt-Affected Conditions

A pot experiment was conducted to study the relative performance of IR 6,KS 282 and IR 10198-66-2 rice varieties cultivated under salt-affected conditions at EC of 6.0,9.0 12.0 dS m(-1) in a sandy clay loam soil havig ECe of 1.6 dS m(-1) treated as control. Six seedlings of 39-day old transplaned to each pot having 12 kg soil. The fertilizer as nitrophos and potassium sulphate at the rate of 57.0, 25.0 and 50.0 mg N,P and K kg(-1) soil respectively was applied at the time of transplanting while zinc sulphate at the rate of 5 mg Zn kg(-1) soil and 43.0 mg N kg(-1) of soil as additional dose were applied 19 and 30 days after transplanting respectively. Normal plant protection measures like number of tillers, panicles, paddy grains, filled and unifilled grains, yield per plant and sterility were recorded and shoot and straw samples were analysed for sodium, potassium, calcium and chloride contents. It was observed that growth and yield of all the varieties were reduced significantly with increasing soil salinity. Na/K and Na/Ca rations in shoot and straw increased significantly with increasing soil salinity. It was also observed that higher values of Na/K and Na/Ca rations in shoots affected growth parameters while higher values of these rations in straw affected yield components and grain yield. However, IR 6 having relatively lower values of Na/K and Na/Ca rations proved to be the most salt-tolerant rice among the three varieties studied

バングラデシュにおける河川堤防の機能と保全に関する調査研究

application/pdfバングラデシュのシラジホンジュ市、マニクゴンジュ市、ラジシャヒ市の道路堤防、ジャムナ川、パッダ川、マヌ川の河川堤防を訪問の際には堤防破壊に関する現地調査、情報収集と共に、現場から土を採取し、基本的物理性試験および締固め試験、透水試験、一軸圧縮試験、三軸圧縮試験等のせん断試験などによって土質性状を求めた。解析によって各地区におけるパラメータ特性の評価行った。ラジシャヒ市ゴダガリ地区の盛土堤防法面保護における実証実験を行い、現地に適した経済的に安価で土砂災害に強い盛土堤防を作り上げる新工法を提案した。Performance and maintenance of road embankments in Sirajgonj district, Manikgonj district, Rajshahi district, Jamuna river embankment, Padma river embankment and Manu river embankment were studied. Soil samples from the failure locations were collected during filed visit. Soil properties were determined by laboratory tests such as compaction tests, unconfined compression tests, triaxial tests and direct shear tests etc. Analytical investigations were performed to evaluate the soil parameters of the damaged areas. Field experiments for slope protection at Godagari Upazilla in Rajshahi district were carried out by using a new composite technology. Results of fields tests, laboratory tests and analyses indicated that the new composite technology is not only economical and strong for slope protection but also viable and appropriate in Bangladesh.平成19~22年度科学研究費補助金(基盤研究(B))研究成果報告書1940503