Evaluation of the influence of various physico-chemical parameters on coastal water quality, around Orissa, by factor analysis

360-364Physico-chemical parameters such as salinity, pH, DO, BOD, chlorophyll-a, nutrients (NO2 N, NO3-N, NH4-N, PO4-P, total phosphorus) and major ions (Ca2+, Mg2+, F) were studied during February-March, 1994 in the coastal waters off Orissa. Data comprising 13 variables obtained from 38 water samples have been subjected to R-mode factor analysis so as to understand the sources, the processes occurring and the influence of various physico-chemical parameters on coastal water quality. About 67.8 % of variance has accounted for three factors such as (i) river run-off or terrestrial input; high positive loading on nutrients with high negative loading on salinity implying that the nutrient economy in the coastal waters off Orissa is primarily dependent on the magnitude of river run-off; (ii) estuarine discharges which include remineralisation of organically bound materials into its dissolved inorganic form or oxidation product of ammonia; high positive loading on nitrite and high negative loading of pH and ammonia in second factor suggest the possibility of oxidation of ammonia to nitrite and (iii) land drainage (including waste discharged from domestic sewage, fertilizer plant and fresh water run-oft) has significant influence on fluoride content in coastal water.</span

New distributional record of <em>Halieutaea Indica </em> (Lophiiformes: Ogcocephalidae) from Chilika lagoon, India

1594-1600The present study provides the first occurrence report of Indian hand fish, Halieutaea indica Annandale & Jenkins, 1910 from Outer Channel of the Chilika Lagoon. This bathy-demersal species is now the only member of the order Lophiiformes known to occur in this brackish water ecosystem. Its incidence for the first time in the Chilika may be attributed to change in the lagoon habitat after the opening of new lagoonal inlets, that subsequently accommodating newer species. This species is a pure marine form and might have entered the lagoon during the higher salinity phase in the lagoon. Present study further described the gut content of Halieutaea indica that comprised of benthic crab, prawn, amphipoda and free-living nematodes

Integrated effect of transplanting date, cultivar and irrigation on yield, water saving and water productivity of rice (Oryza sativa L.) in Indian Punjab: Field and simulation study

Individual effect of different field scale management interventions for water saving in rice viz. changing date of transplanting, cultivar and irrigation schedule on yield, water saving and water productivity is well documented in the literature. However, little is known about their integrated effect. To study that, field experimentation and modeling approach was used. Field experiments were conducted for 2 years (2006 and 2007) at Punjab Agricultural University Farm, Ludhiana on a deep alluvial loamy sand Typic Ustipsamment soils developed under hyper-thermic regime. Treatments included three dates of transplanting (25 May, 10 June and 25 June), two cultivars (PR 118 inbred and RH 257 hybrid) and two irrigation schedules (2-days drainage period and at soil water suction of 16kPa). The model used was CropSyst, which has already been calibrated for growth (periodic biomass and LAI) of rice and soil water content in two independent experiments. The main findings of the field and simulation studies conducted are compared to any individual, integrated management of transplanting date, cultivar and irrigation, sustained yield (6.3-7.5tha-1) and saved substantial amount of water in rice. For example, with two management interventions, i.e. shifting of transplanting date to lower evaporative demand (from 5 May to 25 June) concomitant with growing of short duration hybrid variety (90 days from transplanting to harvest), the total real water saving (wet saving) through reduction in evapotranspiration (ET) was 140mm, which was almost double than managing the single, i.e. 66mm by shifting transplanting or 71mm by growing short duration hybrid variety. Shifting the transplanting date saved water through reduction in soil water evaporation component while growing of short duration variety through reduction in both evaporation and transpiration components of water balance. Managing irrigation water schedule based on soil water suction of 16kPa at 15-20cm soil depth, compared to 2-day drainage, did not save water in real (wet saving), however, it resulted into apparent water saving (dry saving). The real crop water productivity (marketable yield/ET) was more by 17% in 25th June transplanted rice than 25th May, 23% in short duration variety than long and 2% in irrigation treatment of 16kPa soil water suction than 2-days drainage. The corresponding values for the apparent crop water productivity (marketable yield/irrigation water applied) were 16, 20 and 50%, respectively. Pooled experimental data of 2 years showed that with managing irrigation scheduling based on soil water suction of 16kPa at 15-20cm soil depth, though 700mm irrigation water was saved but the associated yield was reduced by 277kgha-1.Rice Date of transplanting Cultivar Crop duration Irrigation Water saving Crop water productivity

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Not AvailableGravity flow on field to field flooding basis is prevalent in most of the canal command areas in India. Furthermore, the canals being mostly unlined and at many sections ill maintained, enormous conveyance loss of water occurs causing dwindling crop production. Hirakud canal command area located in India is no exception to this predicament. Thus, augmentation of irrigation infrastructures vis-à-vis prudent crop planning is of paramount importance for increasing the overall efficiency of the canal system. This paper describes development of optimal crop planning in the Hirakud command area by considering different objectives of planning (scenarios) so that improvement in irrigation efficiency, in terms of water productivity could be feasible. Among various scenarios, the cropping pattern obtained under Scenario—II, i.e. to utilize the maximum area for cultivation, under the constraint of limiting water availability for each outlet was found to be feasible for optimal land and water utilization and generation of requisite employment. However, keeping in view the affinity of the farmers towards paddy (a heavy duty crop), Scenario—III i.e. to utilize the maximum area for cultivation with the constraints of limited irrigation water availability, and providing irrigation to heavy duty crops for at least one-third of the culturable command area of each outlet, can be adopted.Not Availabl

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Field hyperspectral data analysis for discriminating spectral behavior of tea plantations under various management practices

The quality and yield of tea depends upon management of tea plantations, which takes into account the factors like type, age of plantation, growth stage, pruning status, light conditions, and disease incidence. Recognizing the importance of hyperspectral data in detecting minute spectral variations in vegetation, the present study was conducted to explore applicability of such data in evaluating these factors. Also stepwise discriminant analysis and principal component analysis were conducted to identify the appropriate bands for accessing the above mentioned factors. The Green region followed by NIR region was found as most appropriate best band for discriminating different types of tea plants, and the tea in sunlit and shade condition. For discriminating age of plantation, growth stage of tea, and diseased and healthy bush, Blue region was most appropriate. The Red and NIR regions were best bands to discriminate pruned and unpruned tea. The study concluded that field hyperspectral data can be efficiently used to know the plantation that need special care and may be an indicator of tea productivity. The spectral signature of these characteristics of tea plantations may also be used to classify the hyperspectral satellite data to derive these parameters at regional scale