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341.
Smallholder farmers dominate agriculture in Nepal. These farmers have poor knowledge about agriculture and lack of support for soil management and integrated plant-nutrient systems. Focusing on the importance and need for soil-fertility management, a soil-testing mobile van program has recently been introduced in Nepal by Soil Management Directorate, Hariharbhawan. With the introduction of the mobile lab, famers can get their soil tested for nutrient deficiencies and fertilizer requirements at their doorsteps. Using mobile lab, spatial distributions of chemical properties, including pH, organic matter (OM), total nitrogen (N), available phosphorus (as P2O5), and available potassium (as K2O) were examined in soil samples taken from the 0 to 15 cm depth from selected agricultural fields in eight different districts in the mid-hills and Terai regions of Nepal. Tests conducted on 1,479 soil samples in the soil-testing mobile van revealed the following: the mean soil OM ranged from 0.01 to 1.77%; total N content ranged from 0.01 to 0.08%; mean available P2O5 ranged from 16.47 to 197.82 kg ha?1; and mean available K2O ranged from 84.3 to 422.57 kg ha?1. For each crop to be grown, farmers were provided with individual soil health reports and fertilizer recommendations (rate, amount, and type). This program not only allows scientists and farmers to work closely and share information but also serves as a model for the nation to successfully transfer technology for improving soil health and sustainability.  相似文献   
342.
Responsive genotypes, timing and mode of nitrogen application are important for realizing potential yield of winter baby corn. Soil application of nitrogen is a common practice. Foliar application enhances absorption and utilization of nitrogen particularly after anthesis. We investigated combined approach in management of nitrogen for the first time including soil applications followed by foliar urea spray to enhance baby corn yield and profitability. To determine these, 2-year study conducted with three genotypes and six schedules of recommended dose of nitrogen (RDN). Growth characters, productivity traits, harvest period and yields recorded. Nitrogen content and uptake, protein content and harvest were determined. Genotype HM-4 produced 4.6% and 4.1% more cobs and corn weight over HQPM-1. Combined approach resulted higher yield attributes, yields, N uptake, protein harvest and monetary returns. RDN in 4 splits with more basal (B) dose increased cob and corn yield by 4.8% and 5.1% than 3 splits (50% B). Results suggest that HM-4 be grown using RDN 50% as B, 25% at knee height stage, 20% at tassel emergence followed by 5% foliar spray after first picking as urea solution (3%) for achieving higher yield and net returns. More studies needed under diverse conditions.  相似文献   
343.
Magur Clarias batrachus is an indigenous catfish, commonly found in India, Nepal, Bhutan and Bangladesh. Presently, the populations of magur have declined rapidly in their natural habitat mainly due to overexploitation and habitat degradation. Understanding the population genetic structure of the species has significance in improvement of stocks and in conservation of the species. In the present study, simple sequence repeat (SSR) markers were used to differentiate the populations of magur, collected from three geographic locations. For this, a total of 31,814 SSRs were mined from the de novo assembled pooled of whole genome sequence data of C. batrachus. A bioinformatics pipeline with stringent criteria was applied to analyze the data which resulted in selection of 30,142 microsatellite loci falling in the intergenic region. Out of the 25 loci selected for primer development, 16 loci were successfully amplified and 9 loci were found to be polymorphic in this species. The average observed as well as expected heterozygosity in the loci across different stocks varied from 0.652 to 0.688 and 0.864 to 0.873, respectively. These three populations were further segregated into two clusters based on the NJ genetic distance. The Lucknow population formed one cluster, while the Bhubaneswar and Kolkata populations constituted another cluster. A comparable finding was also deduced from the STRUCTURE analyses. The results revealed significant variation among the populations of C. batrachus under study.  相似文献   
344.
An experimental trial was conducted for 90 days to evaluate the growth performance, immunophysiological response of GIFT strain of Tilapia in biofloc‐based rearing system and to assess the relative percentage survival in 3 days after challenging with the virulent strain of Aeromonas hydrophila. Fingerlings with an average body weight 0.98 ± 0.06 g were stocked in triplicate at different stocking densities of 200 (SD1), 250 (SD2), 300 (SD3) and 350 (SD4) m?3 in biofloc‐based treatments and 150 (C) m?3 in control (clear water). Biofloc‐based units (SD1 and SD2) obtained significantly better (P < 0.05) growth performances at the end of the experimental period. Mean body weight of fish in biofloc‐based units showed a decreasing trend with increase in stocking density with 100% survival in all units including control. The stress parameters were significantly lower in biofloc‐based rearing units especially in treatments SD1 and SD2 as compared to the control. The fish from the biofloc‐based units (SD1 and SD2) possessed significantly (P < 0.05) higher immune status as compared to control and other biofloc treatments in terms of respiratory burst, serum lysozyme and myeloperoxidase activity. Relative survival percentages were significantly better in biofloc treatments with highest in SD1 and SD2 (83.33%) after challenge study. GIFT strain of Tilapia at higher stocking densities 200–250 nos m?3 can be taken as optimum stocking density whereas higher stocking densities up to 350 nos m?3 can be reared in the biofloc systems without compromising the growth and immunity.  相似文献   
345.
Five species of snow trout (Schizothorax spp.) were investigated for their inherent nutritional value. Proximate composition, total fat, total cholesterol, triglyceride, fatty acids (FAs) profile, and mineral profiles were analyzed. Protein percentage in all five fish was found to be the same (P > 0.05), ranging from 15% to 18%. Moisture (75–82%) and lipid (1.5–8%) values were found to differ prominently (P < 0.05) in an inverse manner. Total fat (%), total cholesterol (mg/100 g), and triglyceride (mg/100 g) contents were found in the range of 2.73–6.54, 21.31–25.76, and 298.89–342.22, respectively. The trend of FAs in decreasing order was saturated > mono-unsaturated > polyunsaturated (n–6 > n–3). The sum of n–6 FAs value was higher than that of n–3, and the major n–6 and n–3 long chain polyunsaturated FAs (PUFAs) were arachidonic acid and docosahexaenoic acid, respectively. In most of these fish, the profile of macrominerals was phosphorus > potassium > calcium > sodium > magnesium, while the trend for microminerals was iron > zinc > copper > manganese. The snow trout species with best contribution potential to the daily requirement of n–3 long chain PUFAs was found in S. esocinus and S. niger, calcium and phosphorus in S. plagiostomus, and iron and copper in S. progastus.  相似文献   
346.
A feeding trial was conducted to evaluate the effect of inclusion of Sesbania leaf meal in the diet of Cyprinus carpio as a replacer of de‐oiled rice bran (DORB). Bacillus subtilis was used to ferment the Sesbania leaf meal (SLM) to produce FSLM (fermented sesbania leaf meal). Fishes were fed with five isonitrogenous (30% CP) and isocaloric diets for 60 days and treatments were viz., C (30% DORB, 0% SLM), R15 (15% DORB, 15% SLM), R30 (0% DORB, 30% SLM), F15 (15% DORB, 15%FSLM) and F30 (0% DORB, 30% FSLM) by replacing DORB with SLM. A similar growth performance with control was observed in 15% FSLM group while there was a growth reduction in all the raw leaf meal fed groups. Similarly, the expression of insulin‐like growth factor‐1 (IGF‐1) was significantly (p < .05) higher in control and 15% FSLM fed groups. Growth and metabolic enzymes such as protease, amylase, ALT and AST activities were significantly higher in the fermented leaf meal fed groups compared to their non‐fermented counterparts. Antioxidant enzymes, serum transaminase enzymes (SGOT, SGPT) and total bilirubin (TBR) were found to be increased by enhanced level of RSLM, however, reduced by inclusion of FSLM. However, 30% inclusion level of FSLM even after fermentation showed detrimental effect on growth and metabolic response at cellular and molecular level. Thus, the results concluded that fermented Sesbania leaf meal (FSLM) using B. subtilis could replace 50% DORB (15% FSLM group) in the diet of C. carpio without affecting the growth and other physiological responses.  相似文献   
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