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41.
The objective of this study was to DTPA (complexion agent) and a sequential extraction procedure, and adsorption-desorption isotherm (competitive) evaluate the mobility and distribution of Fe, Zn, Mn, Cu, Cd, Ni, and Pb using the in surface samples of five soil great groups differing in their physicochemical properties. For determining heavy metal adsorption and desorption capacities of soil samples, six different concentrations (0, 2.5, 5, 10, 15 and 20 mg Lt) were used in a laboratory experiment with tree replications. An analytical procedure involving sequential chemical extractions has been used for partitioning of heavy metals into five fractions. Sorption isotherms were characterized using linear, Frendlich and Langmuir equations. The results indicated that the selective sequences of the metal adsorption based on the distribution coefficient was Pb〉Cu〉Ni〉Cd〉Zn〉Mn〉Fe and Pb, Cu, and Ni are the most strongly sorbed metals by these soils, whereas Cd, Zn and Mn are the least sorbed ones. The total adsorbed amount of these metals on the studied soils was well described by Langmuir equation. Calciorthid had the highset Pb, Cu, Ni, Cd, Zn, Mn, and Fe adsorption, and the sequences followed order Fluvaquent〉Argiustoll〉Pellustert〉Haplustept of the studied soil.  相似文献   
42.

Wild plants play an important role in the diet of inhabitants in different parts of the world. These plants tend to be drought-resistant and are gathered both in times of abundance and times of need. Used in everyday cooking, these foods may be an important source of nutrients. The purpose of this study was to assess the mineral content of some edible wild leaves. Plants species ( Beta lomatogena Fisch.et Mey., Capparis spinosa L., Chenopodium album L., Eryngium billardieri Delar., Falcaria vulgaris Bernh., Ferula communis L., Gundelia tournefortii L., Lathyrus tuberosus L., Malva neglecta Wallr., Mentha arvensis L., Nepeta concolor Boiss. and Heldr., Ocimum basilicum L., Papaver dubium L., Polygonum bistorta L., Polygonum cognatum Meissn., Portulaca oleracea L., Rheum ribes L . , Rubus sp., Rumex crispus L., Rumex scutatus L ., Scorzonera cana (C.A.Mey.) Hoffm., Scorzonera latifolia (Fish. and Mey.) DC., Scorzonera sp., Sempervivum armenum Boiss et Huet, Tragopogon spp., Urtica urens L.) were collected in late winter and spring, and their taxonomic identifications were made according to Flora of Turkey and analyzed for their mineral content. Moisture content, ash content and pH were found reasonable as compared to some vegetables. However, protein content, N, K, Ca and Mg content of wild plants were higher, while P, S and Na content were lower, and Fe, Mn, Zn and Cu content were equal to, or higher than those of some commonly used vegetables such as spinach, pepper, lettuce, cabbage species.  相似文献   
43.
The use of wastewater for irrigation is increasingly being considered as a technical solution to minimize soil degradation and to restore nutrient contents of soils. The aim of this study is to increase fertility and minimize degradation of soils irrigated with wastewater exposed to different purification treatments. A field experiment was conducted to investigate the effects of control and irrigation with wastewater, which had undergone different purification treatments, on macro‐ and micronutrient distribution within the soil profile and nutrient contents of cabbage (Brassica olerecea var. Capitate cv. Yalova‐1) in Erzurum, Turkey. Wastewater irrigation and preliminary treatment–wastewater irrigation significantly affected soil chemical properties especially at 0–30 cm soil depth and plant nutrient contents after one year. Application of wastewater increased soil salinity, organic matter, exchangeable Na, K, Ca, Mg, plant‐available P, and micro‐elements and decreased soil pH. Wastewater increased also yield and N, P, K, Fe, Mn, Zn, Cu, B, and Mo contents of cabbage plants. Undesirable side effects were not observed in plant heavy‐metal contents, due to salinity and toxic concentrations of metals from the application of wastewater to soil.  相似文献   
44.
Journal of Soils and Sediments - This study was conducted to investigate variations in the stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) of agricultural soils under different...  相似文献   
45.
The effects of calcium and humic acid on seed germination, growth and macro- and micro-nutrient contents of tomato (Lycopersicon esculentum L.) seedlings in saline soil conditions were evaluated. Different levels of humic acid (0, 500, 1000 and 2000 mg kg?1) and calcium (0, 100, 200 and 400 mg kg?1) were applied to growth media treated with 50 mg NaCl kg?1 before sowing seeds. Seed germination, hypocotyl length, cotyledon width and length, root size, shoot length, leaf number, shoot and root fresh weights, and shoot and root dry weights of the plant seedlings were determined. Macro- and micro-nutrient (N, P, K, Ca, Mg, S, Cu, Fe, Mn and Zn) contents of shoot and root of seedlings were also measured. Humic acid applied to the plant growth medium at 1000 mg kg?1 concentration increased seedling growth and nutrient contents of plants. Humic acid not only increased macro-nutrient contents, but also enhanced micro-nutrient contents of plant organs. However, high levels of humic acid arrested plant growth or decreased nutrient contents. Levels of 100 and 200 mg kg?1 Ca2+ application significantly increased N, Ca and S contents of shoot, and N and K contents of root.  相似文献   
46.
ABSTRACT

Lucerne or alfalfa (Medicago sativa L.) is grown as a forage crop on many livestock farms. In calcareous soils in eastern Turkey, lucerne production requires phosphorus (P) additions as the soils are naturally P deficient. Phosphorus sorption isotherms were used to estimate P fertilizer needs for lucerne grown for two years in a 3-cut system on a calcareous P deficient Aridisol in eastern Anatolia, Erzurum province, Turkey. Annual P applications ranged from 0–1200 kg P ha?1. The Langmuir two-surface adsorption equation was used to derive the maximum P sorption capacity of unamended soil and to determine soil solution P, maximum buffer capacity (MBC), equilibrium buffer capacity (EBC), and P saturation at the optimum economic P rate (OEPR) for dry matter (DM) production. Soils were tested for Olson P at the onset of the study and after two years of P applications. In both years, tissue was analyzed for P content at flowering prior to first cutting. The OEPR (2-year average) was 754 kg P ha?1 yr?1 corresponding with a soil solution P concentration of 0.30 mg L?1, a DM yield of 8725 kg DM ha?1, and $528 ha?1 annual profit. The P content of leaves at flowering increased linearly with P application beyond 100 kg P ha?1 and was 3.2 g kg?1 P at the OEPR. The unfertilized soil had an EBC, MBC, P saturation, and Xmax of 3304 mL g?1, 3401 mL g?1, 6%, and 1086 mL g?1, respectively, whereas two years of fertilization to the OEPR decreased EBC and MBC to 358 mL g?1 and 540 mL g?1, and increased P saturation and Olsen P to 56% and 32 mg kg?1, respectively. These results suggest a P saturation >50% or Olsen P >30 mg kg?1 are needed to maintain an optimum soil solution concentration of 0.30 mg L?1 in this calcareous Aridisol. Similar studies with different soils and initial soil test P levels are needed to conclude if these critical soil test values can be applied across the region.  相似文献   
47.
We have examined the effects of Tribulus terrestris (TT), a non-toxic herb, on sex reversal in the Convict Cichlid Cichlasoma nigrofasciatum with the aim of introducing a new environmentally friendly method for masculinization in C. nigrofasciatum. TT is a natural plant product that elevates the testosterone levels in humans and animals. Different concentrations (0.0, 0.10, 0.20 and 0.30 g/l) of TT extract were tested for their effect on sex reversal in C. nigrofasciatum by immersing newly hatched offspring once weekly for 2 months in TT extract. Of the dosages used in the present study, 0.30 g/l TT was the most effective in terms of masculinization, resulting in a maximum male ratio of 87.23% (P < 0.001). Sex ratios of 79 and 85% at 0.10 and 0.20 g/l TT, respectively, were also significantly different from the expected 1:1 ratio (P < 0.001). Histological examinations revealed that the testes of fish treated with TT extract contained all stages of spermatogenesis, clearly demonstrating that the administration of TT extract to C. nigrofasciatum stimulated spermatogenesis. Total survival rates in all treatments and the control were uniformly high, ranging from 88.57 to 90% (P > 0.05). We concluded that TT had no negative effect on the survival rate of C. nigrofasciatum. In addition, all groups of TT-treated fish exhibited successful growth acceleration compared to the control group, but only the 0.30 g/l TT treatment significantly improved the growth rate of C. nigrofasciatum. (P < 0.01). Sex reversal in C. nigrofasciatum demonstrated that TT-treated 0-day-old larvae showed successful sex reversal, spermatogenesis and a better growth rate than untreated progenies.  相似文献   
48.
We investigated in vitro regeneration ability of Prunus microcarpa subsp. tortusa using various explants (root, cotyledon and hypocotyl pieces) and cytokinins [benzyladenine (BA), meta-Topolin (mT) and thidiazuron (TDZ)]. Sectioned cotyledon, root and hypocotyl pieces of in vitro grown seedlings were cultured on Nas and Read Medium (NRM) containing BA (7.5, 10, 12.5, 15 or 17.5 μM), mT (2.5, 5.0, 7.5, 10 or 12.5 μM) or TDZ (2.5, 5.0, 7.5, 10 or 12.5 μM). As a measurement of morphogenetic reaction, the ratios of regenerating explants and the numbers of primary adventitious shoots per regenerating explant were analyzed. Cotyledon explants exhibited higher regeneration ratios than hypocotyl explants, and the root explants were inappropriate for regeneration. Both BA and mT were effective on shoot regeneration but higher regenerating explant ratios were obtained when BA was used. In comparison with BA and mT, the effect of TDZ on enhancing explant regeneration ability was insignificant. Mean number of adventitious shoot per regenerating explant was between 1 and 4, and regenerating explant ratios were between 0% and 77%. The practical appliacations of the results are discussed.  相似文献   
49.
The aim of this study was to investigate the effects of methionine and dithioerythritol, added to the Tris extender, on ram sperm motility and LPO (lipid peroxidation) and antioxidant capacities during liquid storage up to 72 h at 5 °C. Ejaculates collected from five Merino rams, were evaluated and pooled at 37 °C. This study included two experiments. In experiment 1, each pooled ejaculate was divided into four equal aliquots and diluted (37 °C) with the base extender, containing 0 (control), 1, 2 and 4 mM methionine, at a final concentration of approximately 4 × 108 sperms/ml (single step dilution), in a 15-ml plastic centrifuge tube. In experiment 2, dithioerythritol, at concentrations of 0 (control), 0.5, 1 and 2 mM, was used as an additive in the extender, and the procedure explained above was applied for the division of aliquots and the dilution of semen. Diluted semen samples were kept in glass tubes and cooled from 37 to 5 °C in a cold cabinet, and maintained at 5 °C. Sperm motility and LPO and total glutathione (GSH) and glutathione peroxidase (GPx) capacities were determined at 5 °C for periods of 0, 24, 48 and 72 h of liquid storage.The extender supplemented with 1 mM methionine led to higher motility percentages (77.0 ± 1.2%), in comparison to the control group (66.0 ± 4.9%), during 72 h of liquid storage (P < 0.05). As regards dithioerythritol, it did not statistically improve the motility rates for any of the storage times at 5 °C. In biochemical assays, differences in LPO levels between the groups with antioxidants and the control groups were not statistically significant. Compared to the control group, no significant difference was observed in GSH and GPx activities following the addition of methionine, during 72 h of storage. Total GSH and GPx activities did not increase significantly upon supplementation with 0.5 and 1 mM of dithioerythritol, compared to the control group, at any of the time points (P > 0.05). Dithioerythritol at 2 mM led (P < 0.01) to elevating GSH activity, compared to the control group, during 72 h of liquid storage. GPx activity was approximately 10 times higher for 2 mM of dithioerythritol (P < 0.001), compared to that of the control group at all time points.The question regarding the sustainability of sperm survival, LPO and antioxidant capacities following liquid storage of semen remains unanswered. Further studies are required for a better understanding of the biochemical changes and to obtain more information on the determination of lipid peroxidation and antioxidant capacities during cooled storage of ram semen.  相似文献   
50.
The aim of this study was to investigate the frequency and diversity of bovine viral diarrhea viruses (BVDV) infecting cattle in Turkey. A total of 1124 bovine blood samples from 19 farms in 4 different Turkish regions were tested by antigen capture ELISA (ACE). BVDV antigen was found in 26 samples from 13 farms. Only 20 of the 26 initial test positive cattle were available for retesting. Of these, 6 of 20 tested positive for BVDV, by ACE and real-time RT-PCR, one month after initial testing. Phylogenetic analysis, based on comparison of the E2 or the 5'UTR coding regions, from 19 of the 26 initial positive samples, indicated that 17 belonged to the BVDV-1 genotype and 2 to the BVDV-2 genotype. Comparison of 5'UTR sequences segregated 8 BVDV-1 strains (strains 5, 6, 10, 11, 12, 13, 17, and 19) to the BVDV1f, 1 strain (strain 8) to the BVDV1i and 1 strain (strain 14) to the BVDV1d subgenotypes. One strain (strain 4) did not group with other subgenotypes but was closer to the BVDV1f. The remaining 6 BVDV-1 strains (strains 1, 2, 3, 7, 9, and 18) segregated to a novel subgenotype. The E2 sequence comparison results were similar, with the exception that strain 5 grouped with the novel subgenotype rather than BVDV1f subgenotype. It appears that among the diverse BVDV strains in circulation there may be a subgenotype that is unique to Turkey. This should be considered in the design of diagnostics and vaccines to be used in Turkey.  相似文献   
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