Profitability of fertilising young coconut. results of three long-term field experiments

Two long term field experiments on newly cleared lands carried out in the intermediate rainfall zone of Sri Lanka showed that profits of the order of Rs. 3560 to 7120/ha/yr could be obtained during the initial bearing period from systematic NPK fertilizer application to young palm. Total income from the fertilized palms during carried out on underpalned young palms in the same rainfall zone are Rs. 315 to 3950/ha/yr and Rs. 1580 to 7900/ha/yr respectively. Breakeven point of net present value of investment in the early years and the returns fall on the 6th and 9th year in the new plantation and 15 th year in the underplanted land. To the underplanted experiment, palms which had not recieved fertilizers for the initials 17 years, had notrecovered, even after continued fertilization subsequently for 10 years

Nitrate Pollution and Fecal Coliform Contamination in Domestic Wells in the Vavuniya District Sri Lanka with Special Reference to Hospital Area

Ground water is generally  polluted by leachates  from sewage and  agricultural lands. The main pollutants from sewages are nitrate nitrogen and fecal coliform. Both are hazardous when its level at high concentration in drinking water.  The objectives of the study were to evaluate the nitrate nitrogen and fecal coliform count  in  wells and identify the wells that are not suitable for drinking purpose in Vavuniya District, Sri Lanka.  Thirty three   dug wells  and three tube wells were selected around the general hospital Vavuniya to measure the Nitrate Nitrogen (N03-N), and fecal coliform count from March 2008 to February  2009. Mean NO3- N ranged from 0.40 to 16.2 mg/l over a twelve months period and  30.5 % of the wells were above the  permissible limit of 10mg/l (well No11,12,13, 17,18,20,21,23, 25, 29  & 33) and these  wells are not suitable for drinking purpose in almost all the months. Nitrate nitrogen in wet season was significantly higher than dry season (p= 0.072). The depth of wells varied from 4m to 8m and most of  these wells were shallow wells. Shallow wells  are very vulnerability to nitrate pollution  in permeable soil. Almost all the wells were contaminated  with fecal coliform.  Wells closer to sand beds  were contaminated with very high amount (more than 500) of  fecal coliform. Improper  sewage disposal system could be the reason for high nitrate nitrogen and  fecal coliform contamination in wells around the hospital area

Thermophoresis effects on non-Darcy MHD mixed convective heat and mass transfer past a porous wedge in the presence of suction/injection

An analysis is presented to investigate the effect of thermophoresis particle deposition and variable viscosity on non-Darcy MHD mixed convective heat and mass transfer of a viscous, incompressible and electrically conducting fluid past a porous wedge in the presence of suction/injection. The wall of the wedge is embedded in a uniform non-Darcian porous medium in order to allow for possible fluid wall suction or injection. The governing partial differential equations of the problem, subjected to their boundary conditions, are solved numerically by applying an efficient solution scheme for local nonsimilarity boundary layer analysis. Numerical calculations are carried out for different values of dimensionless parameter in the problem and an analysis of the results obtained show that the flow field is influenced appreciably by the applied magnetic field. The results are compared with those known from the literature and excellent agreement between the results is obtained

Response of coconut (Cocos nucifera) to N, P and K fertilizer application from the time of field planting on a latertic gravel soil in Sri Lanka

The results of a long term 3x3x3 NPK field experiment with coconut from the seedling stage upto initial bearing period on a lateritic gravel soil in Sri Lanka, where the rates of fertilizers were progressively increased upto the 16th year, are discussed. The data from the sulphate of ammonia, 1.136 kg saphos phosphate and 2.043 kg muriate of potash/palm/yr from the 16th year. Application of 1.362 kg each of sulphate of ammonia, saphos phosphate and muriate of potash between the 9th and the 16th years produced an yield of 20.7 kg copra/palm/yr from the 13th to the 16th years, which is about 150perc. higher than the plots which received no fertilizer from the seedling stage. The data suggest that in the current fertilizer recommendations, for both young and adult palms, the rate of N could be reduced and that of K increased