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121.
Distillery effluent, a foul smelling, dark coloured by-product of distillery industries, is usually applied as irrigation water or as an amendment to arable land in some areas which are in the vicinity of the distillery industries. A field experiment on soybean–wheat system was conducted for 3 consecutive years in a Vertisol of central India to evaluate the effect of distillery effluent (DE) as an amendment on soil properties and crop productivity. The treatments were control (no fertilizer or manure or DE, T1), 100% NPK + FYM @ 4 Mg ha−1 to soybean (T2) and four graded levels of DE, viz.: 2.5 cm DE to soybean and wheat on residual nutrition (T3), 2.5 cm DE to soybean and 1.25 cm to wheat (T4), 5 cm DE to soybean and wheat on residual nutrition (T5), 5 cm DE to soybean and 2.5 cm to wheat (T6). The organic carbon, microbial biomass carbon and electrical conductivity (EC) of the surface (0–10 cm) soil increased significantly with application of DE compared to T1 and T2, but the soil pH was not affected. The EC increased from 0.47 dS m−1 and 0.58 dS m−1, respectively, in T1 and T2 to 1.52 dS m−1 in T6, where highest dose of DE was applied. This indicated a slight build-up of salinity with DE application. The application of DE showed a significant improvement in the physical properties of the soil. The mean weight diameter (MWD), saturated hydraulic conductivity, water retention at field capacity and available water content were significantly (P < 0.05) higher, while bulk density (BD) and penetration resistance of the surface soil were significantly lower (P < 0.05) in all DE treated plots except in T3 than those in T1 and T2. The fractions of WSA of more than 1 mm diameter in T6, T5 and T4 were, respectively, 141%, 107% and 116% more than the control. The MWD showed a positive linear relationship with the organic carbon (r = 0.84**) and microbial biomass carbon (r = 0.90**) of the soil. A significant (P < 0.01) negative linear relationship (r = 0.70**) was found between soil organic carbon and BD. Except T3, all the DE treated plots recorded significantly higher total and microporosity of the soil than control. Water retention at permanent wilting point and macroporosity of the soil were not affected by treatment. The seed yield of soybean in all the DE treatments was similar with T2 (1.86 Mg ha−1) but significantly more than control (1.28 Mg ha−1). The DE application levels have not affected the seed yield of soybean. In wheat highest grain yield was recorded in T2 (3.47 Mg ha−1), which was similar with T4 (3.16 Mg ha−1), T5 (3.22 Mg ha−1) and T6 (3.46 Mg ha−1). DE application up to T4 level was found suitable from productivity, salinity and sustainability point of view. The study showed that judicious application of DE as an amendment to the agricultural field could be considered as a viable option for safe disposal of this industrial waste. 相似文献
122.
N. Biswas Richard G. Zytner J. A. McCorquodale J. K. Bewtra 《Water, air, and soil pollution》1991,60(3-4):361-380
Many toxic volatile organic compounds (VOCs) are being released to the soil through improper waste disposal practices, industrial impoundments, landfills and accidental spills during transport and handling. Once released, the VOCs migrate toward the groundwater and cause contamination. One of the most frequently found VOCs in groundwater supplies is perchloroethylene (PCE). In this study an attempt was made to investigate the transport of PCE in two types of soil. PCE spills were created on soil columns in the laboratory and column breakthrough theory was used to analyze the data. Empirical equations were used to calibrate a contaminant transport model. The programs for this simple model have been prepared for use with IBM microcomputers and are capable to predicting the breakthrough time and concentration of PCE at various depths in the profile. 相似文献
123.
Appropriate nitrogen (N) management practices are of critical importance in improving N use efficiency (NUE), maize (Zea mays) yield and environmental quality. A six-year (2005–2010) on-farm trial was conducted in Ottawa, Canada to assess the effects of N rates and application methods on grain yield and NUE. In four out of the six-year study, grain yield increased by 60–77 kg ha?1 by sidedress, compared to 49–66 kg ha?1 for each kg N ha?1 applied at preplant. Grain yield response to N between the two strategies was similar in the other growing seasons. Sidedress strategy required 15 kg N ha?1 less of the maximum economic rate of N (MERN) than preplant application. Our results indicate that sidedress application of 90–120 kg N ha?1 with a starter of 30 kg N ha?1 resulted in greater yield, grain quality and NUE than preplant N application in this cool, humid and short growing-season region. 相似文献
124.
125.
A George RA Shah R Sharma P Palta SK Singla RS Manik MS Chauhan 《Reproduction in domestic animals》2011,46(3):444-447
Parthenogenetic activation using zona‐free oocytes offers an alternative model that could be applied to develop protocols for the activation of reconstructed embryos for cloning. The aim of this study was to compare the efficacy of different methods for the activation of zona‐free buffalo oocytes in terms of their effects on the developmental competence of parthenogenetic embryos. The effects of zona removal on parthenogenetic activation and in vitro developmental competence of metaphase II oocytes were also examined. All activation methods were followed by incubation of 2 mm 6‐dimethylaminopurine (6‐DMAP) for 4 h. Out of three different pulse strengths (1.2, 2.1 or 3.3 kV/cm) used, 2.1 kV/cm resulted in the highest blastocyst rate (25.3%). On comparing different chemical agents and electric pulse, highest blastocyst rate was observed for calcium ionophore (CaI) (28.6%) followed by ethanol (25.0%), electric pulse (22.5%) and combined CaI and ethanol treatment (16.7%) although differences among them were not significant. Furthermore, a significantly reduced developmental potential was observed in zona‐free oocytes when compared to zona‐intact ones up to the blastocyst stage (44.3% vs 27.1%). In conclusion, zona‐free buffalo oocytes can be successfully activated for parthenogenetic development using chemical or electrical stimulation. Out of different agents examined, CaI followed by 6‐DMAP resulted in the highest blastocyst rate. 相似文献
126.
Radar detection of cloud-seeding effects 总被引:1,自引:0,他引:1
Hobbs PV Lyons JH Locatelli JD Biswas KR Radke LF Weiss RR Rangno AL 《Science (New York, N.Y.)》1981,213(4513):1250-1252
The effects on precipitation of artificially seeding clouds with Dry Ice have been monitored from cloud to ground with a radar that has a wavelength of 8.6 millimeters. 相似文献
127.
Gouranga Biswas Joy Krushna Jena Sarat Kumar Singh & Hare Krushna Muduli 《Aquaculture Research》2006,37(5):510-514
Fingerling rearing of Indian major carps, Catla catla, Labeo rohita and Cirrhinus mrigala, were conducted in concrete tanks under a polyculture system at a density of 0.3 million fry ha?1 to evaluate the effect of one, two or three feedings per day on growth, survival and feed utilization. Fry were fed with formulated supplementary diet at 10% of biomass per day during the first 15 days, followed by 8% in the next 15 days and 6% thereafter, for 60 days. Feeding of fish three times daily led to higher growth (103.9±8.5 mm/10.3±2.4 g) than those feeding twice (100.2±4.8 mm/9.9±1.5 g) or once (97.2±9.8 mm/9.4±2.1 g) daily, although the values were not significantly different (P>0.05). Survival rate ranging between 72.3% and 75.1% also did not vary significantly (P>0.05) among the treatments. However, higher feeding frequencies resulted in better feed utilization as evident from decreasing feed conversion ratio values. The present study suggested requirement of a higher feeding frequency for rohu compared with catla and mrigal. 相似文献
128.
Alifa Bintha Haque Nidhi Gloria D'Costa Mahi Washim Amit Robert Baroi Nazia Hossain Mashrur Hafiz Sumaiya Rahman Karabi Farhana Biswas 《水产资源保护:海洋与淡水生态系统》2021,31(6):1392-1409
- Devil rays (Mobula spp.) are globally threatened cartilaginous fishes that have attracted global conservation concern owing to their high extinction risk and lack of protection in many countries. Limited resources and data on threatened marine species, including devil rays, impede conservation actions, particularly in developing countries, many of which have high biodiversity.
- Devil ray catch is a component of artisanal fisheries in Bangladesh, but data on their fisheries and trade are limited. To characterize devil ray fishing practices, fishers’ perception and trade, 230 fishers and traders were interviewed between 4 June 2018 and 22 June 2019, in four areas of south-east Bangladesh. Catch data were also opportunistically collected at landing sites.
- Six devil ray species were documented, caught in an array of gill nets, set-bag nets and longlines. All interviewed fishers reported life-long devil ray bycatch in some numbers, and also noted a decline in catch over the last decade. Bottom trawling, increased bycatch levels, increased demand for devil ray products and, in some cases, ecosystem changes were identified by fishers as threats to devil ray populations.
- Unregulated and undocumented trade and retained bycatch, especially by gill nets and set-bag nets, are fuelled by local consumption of devil ray meat and international trade in meat and gill rakers. Compliance with international trade control treaties for all Mobula spp. or the Bangladeshi law protecting Mobula mobular was low, with the majority of fishers (87%, n = 174) unaware of their existence.
- To manage devil ray fisheries, and prevent possible population declines, we propose a combination of legally enforced gear modifications, and catch and trade control through community-owned implementation strategies. Additionally, we propose the simultaneous implementation of inclusive, community-based awareness and stewardship projects in conjunction with a coast-wide ray monitoring programme. Finally, we emphasize that more research and action rooted in a sustainable fishery model is urgently needed to protect Bangladeshi devil ray populations.
129.
选用地理纬度相似的中国辽宁省、美国俄亥俄州新近育成的大豆品种,分别和中国辽宁省20世纪20年代老品种进行了农艺性状的比较研究。结果表明:中美大豆品种主要农艺性状遗传改进的共有趋势是主茎荚数、单株荚数、3粒和4粒荚率、单株粒数、单株粒重、百粒重、粒茎比、收获指数明显增加。株高、主茎节数、节间长度和分枝数显著降低。美国新品种的单株荚数、单株粒数和粒茎比的增加幅度明显高于同期的中国新品种。而中国新品种的百粒重显著高于美国新品种。施肥水平对不同年代大豆品种主要农艺性状也有一定影响,且美国新品种在高肥条件下比中国新品种表现出更高的增产潜力。 相似文献
130.
Optimal Stocking Density with the Provision of Self‐feeders for Striped Knifejaw,Oplegnathus fasciatus (Temminck and Schlegel 1844)
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To determine the optimal stocking density, three densities of 5 (SD5), 10 (SD10), and 15 kg/m3 (SD15) were used to culture striped knifejaw, Oplegnathus fasciatus, for 10 wk. A total of 10, 20, or 30 juveniles with mean weights of approximately 96 g were stocked into one of nine 300‐L tanks (with an initial water volume of 200 L) and fed with commercial feed via self‐feeders. The fish were sampled at 4 and 8 wk, and the stocking density was maintained by adjusting the water volume of the tanks. The final body weights in SD10 and SD15 were 183.8 and 178.9 g, respectively, which were significantly higher than 161.7 g in SD5 (P< 0.05). However, there was no significant difference between the SD10 and SD15 (P > 0.05). A similar trend was observed in the specific growth rate among the treatments. Feed efficiency and the lipid retention efficiency were both significantly higher in SD10 than that in SD5. The plasma levels of cortisol, glucose, and total protein were similar among the treatments. These results clearly suggest that densities of 10 and 15 kg/m3 can be used to improve the growth performance of striped knifejaw, O. fasciatus, when fed with a self‐feeder. 相似文献