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1.
An attempt was made in the present investigation to utilize the vast deposit of rock phosphate （RP） of India by preparing nano RP using modem tool of nano-science and nano-technology for field application to maize crop （Zea mays L.）. To evaluate the efficacy of different nano RP, a field experiment was conducted during kharif season （June to September） of 2012 at India Institute of Soil Science （IISS）, Bhopal, taking maize as a test crop. The experiment consisted of five treatments （control, NK （100%）, NPK （100%）, NK （I00%） ＋ 60 kg P205） as nano RP through Udaipur nano RP （34% P205） and Udaipur nano RP （31% P205） were tested in randomized block design with four replications. The results showed that the shelling percentage, 1,000 grain weight, grain and stover yield, etc., were significantly higher in the maize plant treated with Udaipur nano RP （34% P205） as compared to the control, which was being at par with single super phosphate （SSP） treated plants. The total P content and its uptake were higher （0.65% and 40.29 kg/ha） in SSP treated plant, which was closely followed by Udaipur nano RP 34% （0.63% and 38.29 kg/ha） over the control （0.60% and 27.82 kg/ha）. The SSP treated plants had significantly highest apparent P recovery （47.98%） which was comparable to Udaipur nano RP （34% P205）, where as the Udaipur nano RP （31% P205） had the lowest. The additional N and K uptake by the plant was also observed with application of P sources, which were ranged from 16.5 kg/ha to 37.2 kg/ha and 27.9 kg/ha to 64.7 kg/ha under different P treatments. These results showed that crop utilization of P from nano RP was at par with that of P from SSP while yield response to P from nano RP was marginally lower than to P from SSP but serve as a cheaper source.  相似文献   

2.
The industrial production of the phosphoric acid is important and makes itself in a big number of countries. The by-product descended of this industry, residuary gypsum called phosphogypsum, poses a major environmental problem. The aim of this work is to identify and to value the potentialities of valorization of the by-product phosphogypsum produce in Morocco, for a use in the domain of agriculture. They can contain 1% to 6% of free acids. The idea is to use this acid to partially solubilize natural phosphate and to make the final product richer in phosphorus （about I0% of total P205 half soluble） and therefore more attractive on the agronomic and economic plan. For mixtures phosphogypsum/natural phosphate, a study of clarification is necessary, by varying the proportions of products, the humidities, mixing techniques, the ripening time to achieve a final interesting product. The dynamics of the phosphor in soil has been measured by the Olsen method and the one in the plant has been measured after drying in the steamroom to a temperature of 70 ~C to 75 ~C during 72 hours. A trial hold is incinerated. The ashes are taken by acid hydrochloric extract and the phosphor is measured out with the help of an UV spectrometer to 430 nm. The pH has been followed with the help of a pH-meter. The phosphor presents a remarkable dynamics in mixture with the phosphogypsum.  相似文献   

3.
Soil organic carbon （SOC） and soil Olsen-P are key soil fertility indexes but information on their relationships is limited particularly under long-term fertilization. We investigated the relationships between SOC and the percentage of soil Olsen-P to total P （PSOPTP） under six different 15-yr （1990-2004） long-term fertilizations at two cropping systems in northern China. These fertilization treatments were （1） unfertilized control （control）; （2） chemical nitrogen （N）; （3） N plus chemical P （NP）; （4） NP plus chemical potassium （NPK）; （5） NPK plus animal manure （NPKM） and （6） high NPKM （hNPKM）. Compared with their initial values in 1989 at both sites, during the 1 lth to 15th fertilization years annual mean SOC contents were significantly increased by 39.4-47.0% and 58.9-93.9% at Gongzhuling, Jilin Province, and Urumqi, Xinjiang, China, under the two NPKM fertilizations, respectively, while no significant changes under the no-P or chemical P fertilization. During the 1 lth to 15th fertilization years, annual mean PSOPTP was respectively increased by 2.6-4.2 and 5.8-14.1 times over the initial values under the two chemical P fertilizations and the two NPKM fertilizations, but was unchanged in their initial levels under the two no-P fertilizations at both sites. Over the 15-yr long-term fertilization SOC significantly positively correlated with PSOPTP （r^2=0.55-0.79, P〈0.01）. We concluded that the combination of chemical P plus manure is an effective way to promote SOC accumulation and the percentage of soil Olsen-P to total P at the two mono-cropping system sites in northern China.  相似文献   

4.
The responses of five inter-specific lowland rice cultivars （NERICA-L-19, NERICA-L-20, NERICA-L-41, NERICA-L-42, and NERICA-L-60） and four improved Oryza sativa cultivars （FKR 19, BW 348-1, WITA 4, and SIPI 6923033） to levels of phosphorus and nitrogen fertilization were compared on a Typic Natrustalfat Kadawa in the Nigerian Sudan Savanna in 2006 and 2007 The responses of the NERICA-L eultivars to N and P fertilization were similar to the O. sativa cultivars. In a dry year （2007）, the NERICA-L cultivars gave higher yields than O. sativa cultivars. Phosphorus level did not significantly affect crop physiology, yield, and yield components of all the cultivars. Pooled across cultivars, N and P levels, days to panicle initiation, mid-flowering and maturity were, respectively delayed by 17.0, 15.6 and 6.4 days in 2007 compared to 2006. NERICA-L-42 and NERICA-L-41 were the most stable, exhibiting the least difference in duration to maturity between the two years （3.5 and 4.4 days, respectively）, and could therefore be more adapted to rain-fed environments prone to frequent droughts. Increasing N levels from 0 to 120 kg hal produced yield increments of 62.9 and 37.2% in 2006 and 2007, respectively. Cultivars FKR 19 and WITA 4 gave higher yields in 2006 （3940 and 3542 kg ha^-1, respectively）, while in 2007, NERICA-L-42, NERICA-L^-19 and NERICA-L-20 ranked among the highest in grain yield （3935, 3807 and 3726 kg hal, respectively） and could be recommended to resource-poor farmers. a  相似文献   

5.
Phosphorus change point indicating the threshold related to P leaching, largely depends on soil properties. Increasing data have shown that biochar addition can improve soil retention capacity of ions. However, we have known little about weather biochar amendment influence the change point of P leaching. In this study, two soils added with 0, 5, 10, 20, and 50 g biochar kg-1 were incubated at 25℃ for 14 d following adjusting the soil moisture to 50% water-holding capacity （WHC）. The soils with different available P values were then obtained by adding a series of KH2PO4 solution （ranging from 0 to 600 mg P kg-1 soil）, and subjecting to three cycles of drying and rewetting. The results showed that biochar addition significantly lifted the P change points in the tested soils, together with changes in soil pH, organic C, Olen-P and CaC12-P but little on exchangeable Ca and Mg, oxalate-extractable Fe and Al. The Olsen-P at the change points ranged from 48.65 to 185.07 mg kg-1 in the alluvial soil and 71.25 to 98.65 mg kg^-1 in the red soil, corresponding to CaCl2-P of 0.31-6.49 and 0.18-0.45 mg L~, respectively. The change points of the alluvial soil were readily changed by adding biochar compared with that of the red soil. The enhancement of change points was likely to be explained as the improvement of phosphate retention ability in the biochar-added soils.  相似文献   

6.
The accurate assessment of the spatiotemporal changes in soil nutrients influenced by agricultural production provides the basis for development of management strategies to maintain soil fertility and balance soil nutrients. In this paper, we combined spatial measurements from 2 157 soil samples and geostatistical analysis to assess the spatiotemporal changes in soil organic carbon （SOC）, total nitrogen （TN）, available phosphorus （AP） and available potassium content （AK） from the first soil survey （in the 1980s） to the second soil survey （in the 2000s） in the Taihu region of Jiangsu Province in China. The results showed that average soil nutrients in three soil types all exhibited the increased levels in the 2000s （except for AK in the yellow brown soil）. The standard deviation of soil nutrient contents increased （except for TN in the paddy soil）. Agricultural production in the 20 years led to increases in SOC, TN, AP and AK by 74, 82, 89 and 65%, respectively, of the Taihu areas analyzed. From the 1980s to 2000s all the nugget/sill ratios of soil nutrients indices were between 25 and 75% （except for AK in the yellow brown soil in the 2000s）, indicating moderate spatial dependence. The ratio of AP in the yellow brown soil in the 2000s was 88.74%, showing weak spatial dependence. The spatial correlation range values for SOC, TN, AP and AK in the 2000s all decreased. The main areas showing declines in SOC, TN and AP were in the northwest. For AK, the main region with declining levels was in the east and middle of western areas. Apparently, the increase in soil nutrients in the Taihu region can be mainly attributed to the large increase in fertilizer inputs, change in crop systems and enhanced residues management since the 1980s. Future emphasis should be placed on avoiding excess fertilizer inputs and balancing the effects of the fertilizers in soils.  相似文献   

7.
Phosphorus （P） is a major growth-limiting nutrient, and unlike the case of nitrogen （N）, there is no large atmospheric source that can be made biologically available. Moreover, P governs crucial role in plant as it stimulates root development and growth, gives plant rapid and vigorous start leading to better tillering and essential for many metabolic processes for seed formation. Soil microbes play very important role in bio-weathering and biodegradation. The microorganisms produce low molecular mass organic acids, which attack the phosphate structure and transform phosphorus from non-utilizable to the utilizable for the plants form. The test of the relative efficiency of isolated strains is carried out by selecting the microorganisms that are capable of producing a halo/clear zone on a plate owing to the production of organic acids into the surrounding medium. It is a well-known fact that as the particle size of rock phosphate decreases, the microbe mediated solubilization of rock phosphate increases in soil. In the present investigation, microbial solubilization of nano rock phosphate （〈 100 nm） particles was studied. Experimental results revealed that Pseudomonas striata solubilized 11.45% of the total P after 24 h of incubation from nano rock phosphate particles while 28.95% and 21.19% of the total P was solubilized by Aspergillus niger （black pigmented） and Aspergillus niger （green pigmented）, respectively. It was also observed that Aspergillus niger has the higher ability to dissolve Udaipur rock phosphate than Pseudomonas striata.  相似文献   

8.
Zea mays var. saccharata （sweet corn） is an important crops grown for food and feed in the tropics. In Indonesia, most of the land used for crops production is characterized by acid pH and low levels of nitrogen and phosphorus. Phosphorus fertilizers have been widely used to improve soil fertility in Indonesia. Given the high cost of superphosphate （SP）, the focus is now on rock phosphate （RP） fertilizer, which is relatively cheaper than SP and shows high solubility in acid condition. The combination of RP and manure during the decomposing process and the addition of decomposing microbes may be a promising technique to overcome the problem. A field experiment was conducted on a vertisol soil （low pH and low available nitrogen and phosphorus）. The objective of the research is to evaluate the effect of combinations of manure enriched with RP （granular and non-granular） with three different decomposing microbes （EM4, starTmik and stardec） on sweet corn and dry matter production, phosphorus （P） and calcium （Ca） content in above-ground biomass. A completely randomized design with seven treatments and four replicates was used in this experiment. The size of the plots was 3 m x 2.5 m. The treatments were TO （manure）, T1 （manure ＋ EM4）, T2 （manure ＋ starTmik）, T3 （manure ＋ stardec）, T4 （manure granular ~ EM4）, T5 （manure granular ＋ starTmik）, T6 （manure granular ＋ stardec）. The manure was enriched with RP 66 kg P/ha （150 kg P2Os/ha） and inoculated with the biodecomposer according to the assigned treatment. The manure was applied in a rate of 30 t/ha. All plot received 125 kg KC1/ha （150 kg K20/ha） and 200 kg urea/ha as basal fertilization. Sweet corn was harvested 70 d after planting. Sweet corn plants were cut close to the ground and analyzed for dry matter yield （DM） and P and Ca content in the biomass. Result showed that sweet corn and DM yield and P content were not significantly influenced by the treatments. Ca content in the above-gro  相似文献   

9.
The experiment was conducted to evaluate the low phosphorus diets supplemented with different sources of phytase in low metabolizable energy （ME） and crude protein （CP） diets in broilers. Four levels of non-phytate phosphorus （NPP） （0.33%, 0.36%, 0.39% and 0.42% of the diet） were employed in six dietary treatments in such a way that the least level of NPP （0.33%） was supplemented with two phytase enzymes namely 6-phytase （Natuphos-5,000） and 3-phytase （Sunphase） along with low nutrient composition viz. 2750 kcal ME/kg and CP 18% in growing phase （21 d-42 d）. A total of 1,400 birds were exposed to six treatments in three replicates except for the phytase supplemented diets which were replicated four times each. Non-significant results are obtained from all performance parameters （body weight gain, feed intake and feed gain） and serum minerals （calcium and phosphorus） between 21 days to 42 days. Non-significant results are seen among all treatments; even supplementation of both types of enzymes did not affect the overall results. The results of the present study demonstrate 0.33% P level without phytase are sufficient in low ME and CP diets.  相似文献   

10.
Phytophthora root and crown rot was found on the fruit trees in Bulgaria for the first time in the period 1998-1999. Monitoring of the disease spread from 2000 to 2007 points out incidence between 2 and 14 per cent, in some orchards and nurseries in the Southern part of Bulgaria. The following Phytophthora species were identified based on morphological and cultural characteristics, and temperature requirements： Phytophthora cactorum, Phytophthora citrophthora, Phytophthora drechsleri, Phytophthora cryptogea, Phytophthora hybrid specie and Pythium. Prevailing specie was P. cactorum. P. cryptogea and P. cactorum were confirmed by application of molecular methods. Nutritional requirements of P. cactorum and P. citrophthora were studied. Most Nitrogen sources stimulated the mycelial growth of P. cactorum to a higher extend, and reduced the colony size ofP. citrophthora. Different Carbon sources were utilized well by P. cactorum, and only saccharose and maltose had a stimulating effect on the mycelial growth of P. citrophthora. MgSO4.7H20 was the preferred sulfur source for both fungi, as L-cysteine and L-methionine only for P. cactorum. Phytophthora infection leads to physiological changes in the.host plant tissues. The tendency traced out is： about disorders in the amino acid metabolism, increase in the total sugars and slight reduction of the cellulose content. The total nitrogen, phosphorus and potassium content are reduced and the calcium and magnesium are increased. Photosynthesis of inoculated plants was suppressed and transpiration was increased.  相似文献   

11.
[Objective] The historical evolution pattern of nitrogen （N）, phosphorus （P） and potassium （K） fertilizer application rate and its effects on lint cotton yield were explored to provide the theoretical basis for reasonable fertilizer management strate-gy in the cotton planting region of the Yangtze River Val ey. [Method] GGE biplot analysis method was adopted to analyze the correlation among N, P and K fertilizer application rate and lint cotton yield with the dataset of national cotton regional trials of the Yangtze River Val ey during 1991-2013. The linear and nonlinear regression analysis method was used to reveal the evolution of the fertilizer applying patterns, and analyze the effects of N, P, K application rates on cotton lint yield. [Result] The application rates of N, P and K fertilizer presented highly significant positive corre-lation with lint cotton yield, among which the potassium fertilizer was the strongest relative factor with lint cotton yield, fol owed by phosphorus fertilizer, while nitrogen fertilizer was the weakest factor. The application rate of nitrogen fertilizer was relat-ed with the test year in the pattern of a quadratic function, while phosphate and potassium had progressive increase linear relation with the test year in the cotton planting region of the Yangtze River Val ey. Meanwhile, cotton lint yield was in re-sponse to nitrogen fertilizer content increase with a quadratic parabola function, and increased with the applying phosphate fertilizer and potassium fertilizer content with linearly increasing function. [Conclusion] The increasing application amount of N, P and K fertilizer was general y beneficial to cotton yield improvements, however, ex-orbitant applying nitrogen fertilizer was unfavorable for cotton production, and a reasonable mixture formula of N, P and K fertilizer was better in terms of cotton yield-increasing effect.  相似文献   

12.
A combination method of the usual-PCR and reverse-PCR for the cloning of a novel lipase gene directly from the total genomic DNA of strain lip35 （Pseudomonas sp.） is described, whereby a lipase gene （lip） was cloned directly from genomic DNA. The sequence data have been deposited in the GenBank and EMBL data bank with the accession number EU414288. The nucleotide sequence showed a major open reading frame encoding a 59-kDa protein of 566 amino acid residues, which contained a lipase consensus sequence GXSXG. The lipase lip had 74 and 70% homologies with the lipases of an uncultured bacterium and P. fluorescens PfO-1, respectively, but it did not show any overall homology with lipases from other origins. The functional lipase was obtained when the lip gene was expressed in Pichia pastoris GS115.  相似文献   

13.
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14.
Transgenic crops having alien genes from different sources are getting popularity. A Rice （Oryza sativa L.） containing gene from Bacillus thuringiensis, a soil bacterium, was assessed to study the potential risks of transgenic plants on environment. The crop was found resistant to target insect pests. Rice variety Basmati-370 transformed with two insecticidal genes, crylAc and cry2A, was grown under field conditions for several years. Data were collected at different stages of the plant growth. Fate of Cry protein in soil, effect of Bt protein on non-target insects, risks of vertical and horizontal gene flow were evaluated. No potential hazard was found at all levels. Bt protein was unstable and degraded significantly in soil within 30 days after harvesting the crop. No harmful effects were found on non-target insects （insects other than order lepidoptera）. Maximum gene flow of 0.02% was observed at close spacing and no evidence of horizontal gene transfer to Rhizobium spp. was found. In conclusion, the transgenic rice plants transformed with Bt genes have no harmful effects on the environment.  相似文献   

15.
This study was carried out the animal production department, genetic engineering lab, college of agriculture, （UoB）, Iraq. The aim of this study was to use the polymerase chain reaction restriction fragment length polymorphism （PCR-RFLP） as a fast, efficient and low cost method to detect the genetic variants of kappa-casein gene （k-CN） in Iraqi buffalo using three different primers specific for bovine k-CN to amplify the gene segment, followed by digestion using restriction enzyme （Hind III） for genotyping. DNA from 50 Iraqi buffaloes was extracted by phenol chloroform method. PCR was carried out in a final reaction volume of 25 μL and the reaction mixture was subjected to standard PCR protocol. The results of this work show that among the examined 50 Iraqi Buffalo were homozygous for the K-CN and genotyped as BB for all three primers but gave different bands. Thus PCR-RFLP using Hind III revealed all the samples to be monomorphic for this locus. The restriction digestion analysis of 397 bp PCR product of k-CN indicates the presence of two fragments of 154 bp and 225 bp for BB-genotype. A 437 bp fragment of the bovine genomic K-CN gene was amplified. One Hind III restriction site is found in position 346 of the amplified fragment of allele k-CN B, yielded 91 bp and 346 bp. Amplified products from Iraqi buffalo （530）, after being digested with Hind III, yielded two separate DNA fragments of different sizes i.e., 160 bp and 370 bp. For the first time completed research such specifications in Iraq, for the first time using molecular biology in genetic identification. Our objectives of this study have been to aid in understanding domestication, Buffalo origin and their history and evolution, to identify genetically unique breeds, to provide an objective basis for conservation decisions and to aid the formulation of breeding plans.  相似文献   

16.
A novel insecticidal gene crylAh was cloned from Bacillus thuringiensis isolate BT8 previously for plant genetic engineering improvement. Truncated active CrylAh toxin has a toxicity level similar to that of the full-length CrylAh toxin. In this study, plant expression vector pMhGM harboring truncated crylAh gene was transformed into maize （Zea mays L.） immature embryos by Agrobacterium tumefaciens-mediated transformation at which maize alcohol dehydrogenase matrix attachment regions （madMARs） were incorporated on both sides of the gene expression cassette to improve gene expression. A total of 23 PCR positive events were obtained with a transformation efficiency of 5% around. Bioassay results showed that events 1-4 and 1-5 exhibited enhanced resistance to the Asian corn borer （Ostriniafurnacalis）. These two events were further confirmed by molecular analysis. Southern blot suggested that a single copy of the crylAh gene was successfully integrated into the maize genome. Western blot and ELISA showed that the foreign gene crylAh was expressed stably at high level in maize and could be inherited stably over generations. The results of a bioassay of T l-T4 transgenic maize plants indicated that the transgenic plants were highly toxic to the Asian corn borer and their resistance could be inherited stably from generation to generation. Thus, events 1-4 and 1-5 are good candidates for the breeding of insect-resistant maize.  相似文献   

17.
【目的】研究硅、磷不同配比对广西赤红壤区甘蔗出苗率、生长速率及产量的影响,寻求适合甘蔗生长的最佳硅、磷配比。【方法】采取二次回归D-最优设计在广西农业科学院网室进行盆栽试验,运用SAS统计分析软件对试验结果进行回归分析,建立多项式回归模型,并通过计算机程序对模型进行仿真寻优。【结果】施磷有较好的甘蔗产量收益,而合适的磷、硅配施,有利于甘蔗出苗及生长,并可获得较高的甘蔗产量。甘蔗产量水平与磷素（x1）、硅素（x2）间的回归模型为：y=4.080+0.254x1-0.068x2+0.077x1x2-0.315x12-0.207x22。磷和硅最佳施用量分别为7.5 g/盆（P2O5） 和7.2 g/盆（SiO2）,磷与硅最佳配施比例为7.5∶7.2,甘蔗产量为4.12 kg/盆,经济效益为1.82元/盆。【结论】建立的甘蔗产量与硅、磷肥用量的回归模型可用作同类甘蔗地土壤的施肥决策和预报,磷（P2O5）和硅（SiO2）的最佳比例为7.5∶7.2。  相似文献   

18.
Deep phosphorus application can be a usefull measure to improve crops＇ performance in semi-arid regions, but more knowledge of both its general effects and effects on specific crops is required to optimize treatments. Thus, the aims of this study were to evaluate the effects of phosphorus（P） application at different soil layers on root growth, grain yield, and water-use efficiency（WUE） of winter wheat grown on the semi-arid Loess Plateau of China and to explore the relationship between root distribution and grain yield. The experiment consisted of four P treatments in a randomized complete block design with three replicates and two cultivars： one drought-sensitive（Xiaoyan 22, XY22） and one drought-tolerant（Changhan 58, CH58）. The four P treatments were no P（control, CK）, surface P（SP）, deep P（DP）, and deep-band P application（DBP）. CH58 produced larger and deeper root systems, and had higher grain yields and WUE, under the deep P treatments（DP and DBP） than under SP, clearly showing that deep P placement had beneficial effects on the drought-tolerant cultivar. In contrast, the grain yield and root growth of XY22 did not differ between DP or DBP and SP treatments. Further, root dry weight（RW） and root length（RL） in deep soil layer（30-100 cm） were closely positively correlated with grain yield and WUE of CH58（but not XY22）, highlighting the connections between a well-developed subsoil root system and both high grain yield and WUE for the drought-tolerant cultivar. WUE correlated strongly with grain yield for both cultivars（r=0.94, P〈0.001）. In conclusion, deep application of P fertilizer is a practical and feasible means of increasing grain yield and WUE of rainfed winter wheat in semi-arid regions, by promoting deep root development of drought-tolerant cultivars.  相似文献   

19.
基于“3414”方案的杭白菊施肥效应研究   总被引：1，自引：0，他引：1  
采用"3414"田间试验方案,研究了沿海地区不同氮磷钾肥配比对杭白菊产量的影响,建立了杭白菊产量(Y)与施氮量(N)、施磷量(P)、施钾量(K)之间的回归方程:Y=702.486+15.289N+9.866P+5.892K-0.310 N2-0.068P2-0.059 K2+0.609NP+0.435NK+0.380PK。据此计算得出杭白菊的最高经济产量为19076.2 kg/hm2,氮、磷、钾肥的最佳施用量分别为N 378.5 kg/hm2、P2O5274.8 kg/hm2、K2O 362.7 kg/hm2。氮肥对杭白菊的增产效应最明显,其次是磷肥。  相似文献   

20.
The study was conducted to reveal P fractions and N forms changing characters during composting of pig manure with rice straw.During composting,the NH 4 ＋-N concentration decreased and reached at a relatively low value（〈400 mg kg-1） in the final compost,while the NO 3--N concentration increased.Total N losses mainly occurred during thermophilic phase due to the high temperature,the high NH 4 ＋-N concentration and the increase of pH value.Labile inorganic P was dominated in the pig manure and initial compost mixture.During composting,the proportion of labile inorganic P of total extracted P decreased,while the proportion of Fe＋Al-bound P,Ca＋Mg-bound P and residual P increased.The evolutions of the proportion of labile inorganic P,Fe＋Al-bound P and Ca＋Mg-bound P were well correlated with the changes of pH value,organic matter and C/N ratio.Therefore,composting could increase the concentration of N and P and decrease the presence of NH 4 ＋-N and labile P fractions which might cause environmental issues following land application.  相似文献   

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