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991.
Dais P Spyros A Christophoridou S Hatzakis E Fragaki G Agiomyrgianaki A Salivaras E Siragakis G Daskalaki D Tasioula-Margari M Brenes M 《Journal of agricultural and food chemistry》2007,55(3):577-584
The present study was designed to assess the agreement between analytical methodologies based on 1H and 31P NMR spectroscopy and conventional analytical methods (titration, gas chromatography, and high performance liquid chromatography) for measuring certain minor and major constituents (free acidity, fatty acids, iodine value, and phenolic compounds) of olive oil. The standard deviations of the NMR method were comparable to those of the conventional methods, except perhaps those of the total hydroxytyrosol and total tyrosol. Linear regression analyses showed strong correlations between NMR and conventional methods for free acidity, total hydroxytyrosol, total tyrosol, total diacylglycerols, (+)-pinoresinol, (+)-1-acetoxypinoresinol, and apigenin; good correlations for linoleic acid, free hydroxytyrosol, and free tyrosol; and weak correlations for oleic acid, linolenic acid, saturated fatty acids, and luteolin. Furthermore, a method comparison study was conducted and the agreement between NMR and conventional methods was evaluated by using the Bland and Altman statistical analysis. The distribution of the data points in the bias plot showed that 96.4% and 100% of the measurements of free acidity and iodine value, respectively, were within the limits of agreement of the two methods. For the remaining constituents of olive oil, the percentage of measurements, located within the limits of agreement, ranged from 94% to 98.5%. 相似文献
992.
Arias-Estévez M López-Periago E Nóvoa-Muñoz JC Torrado-Agrasar A Simal-Gándara J 《Journal of agricultural and food chemistry》2007,55(18):7541-7546
When used to fine wines, bentonite acquires a protein load that makes it a potentially useful fertilizer. Other properties of bentonite are also potentially useful for soil amendment. In the work described in this paper, waste bentonite from a winery was applied to an acid soil, and its effects on soil properties and on the growth of Lolium multiflorum were evaluated. Soil N, K, and P contents all increased, as did pH and cation exchange capacity. Biomass production increased as the dose of bentonite increased up to 5 g kg(-1), decreasing at larger doses (possibly as a result of falling potassium/magnesium ratio and increasing electrical conductivity). Environmental drawbacks of waste bentonite include its high soluble copper content, although its conversion in the soil to less soluble forms reduces its potential phytotoxicity. The copper, manganese, and zinc contents of the ryegrass crop were low. 相似文献
993.
Pedro Mondaca Alexander Neaman Sébastien Sauvé Eduardo Salgado Manuel Bravo 《植物养料与土壤学杂志》2015,178(3):452-459
We studied the fate of Cu in contaminated semiarid soils from two areas with different mining activities in central Chile. Several regression models were evaluated to use soil physicochemical characteristics to predict solubility, partitioning, and activity of Cu. Furthermore, we hypothesize that the type of Cu mining compound (smelter dust versus tailing sand) can be another important variable determining the bioavailability of Cu. In the studied neutral to alkaline soils, soil organic matter (SOM) enhanced Cu solubility most probably through the formation of organic complexes with dissolved organic C (DOC). As a consequence, Cu solubility and partitioning were better explained by DOC concentration than by SOM content. On the other hand, Cu activity was mainly related to soil pH and was not affected by DOC. Although we found differences between the two study areas, Cu solubility and partitioning might not be as dependent upon the origin of the Cu mining compound as upon other physiochemical characteristics that influence the concentration and characteristics of DOC. Total Cu, pH, and DOC would be the most important variables to consider on Cu solubility, however, data about the nature of SOM may certainly improve the prediction models. Thus, multiple binding site models between Cu and DOC should be studied to improve predictions of Cu solubility. 相似文献
994.
Juan Manuel Antolín Valentín Pando Fernández Carmen T. Bravo Sánchez 《Compost science & utilization》2013,21(3):205-213
A 4-year field study was carried out to investigate the effects of three types of biowastes application on PCB accumulation in agricultural soils. This study was based on the experiments designed for four soils in two areas of Palencia province (Spain) (Cerrato and Tierra de Campos) for non irrigated and irrigated land after applying biowaste. The amounts of the three different types of biowastes added were determined according to the fertilization needs of nitrogen for the crop. The concentrations of PCBs in soils were determined before and after biowaste application. The three biowaste treatments raise the concentration of PCBs in the soil, sewage sludge compost (SC) treatment produced the main increase in PCBs concentration, followed by municipal solid waste compost (MC) treatment and the dehydrated sewage sludge (SD) treatment. The values of biowaste treated areas were 3.7-11.5 times higher than the respective values of the non treated areas. Changes observed in the congener distribution also suggest the influence of the biowaste on the soil. The biowaste used had an average PCBs concentration of 63.16 ng g?1 with a range from 34.08 ng g?1 to 118.93 ng g?1, which are values below the EEC recommended limit (800 ng g?1). In the soils without treatment was found an average concentration 0.206 ng g?1 of PCBs, typical of areas with low levels of environmental pollution. 相似文献
995.
Inoculation with biocontrol agents can affect iron (Fe) uptake by plants. The objective of this research was to study the necessity of defining a Fe threshold in growth media for the inoculation with the biocontrol agent Trichoderma asperellum T34. A completely randomized experiment with cucumber (Cucumis sativus L.) was performed involving two factors: Fe rate in the growth medium in the form of ferrihydrite (0, 8, 16, 32.5, and 75 mg kg–1 of citrate‐ascorbate‐extractable Fe (CA‐Fe), and plant inoculation with T34. Dry matter (DM) of aerial parts of cucumber was decreased by T34. This was related to a decreased accumulation of Fe in plants, more in aerial parts than in roots. However, at the highest Fe rate (75 mg kg–1), differences in DM yield, plant height, and the content and concentration of Fe in shoots between inoculated and noninoculated plants were not significant. The threshold of CA‐Fe in the medium for DM yield of cucumber was 37 mg kg–1 without T34. With T34, this threshold was 65 mg kg–1, which implies that, below this limit, additional Fe supply is required for inoculation with T34. 相似文献
996.
Manuel Sandoval Villa Gabriel Alcántar González Juan Luis Tirado Torres Andrés Aguilar Santelises 《Journal of plant nutrition》2013,36(11):2545-2557
Previous experiments have indicated that under greenhouse and hydroponic conditions, spring wheat (Triticum aestivum L.) produces higher yields, more tillers and dry matter when supplied with mixtures of NH4 and NO3 than when supplied with only one of them. The goal of this study was to evaluate the effect of selected ammonium and nitrate mixtures on dry matter yield, content of soluble protein, and phosphoenolpyruvate carboxylase (PEPCase) and glutamine synthetase (GS) enzymatic activities. Cultivar ‘Salamanca’ wheat plants, 21 days old, were grown in one of five solutions containing one of the following: 7/0, 5/2, 3.5/3.5, 2/5 or 0/7 meq l‐1 of NH4NO3. After two weeks of treatment applications, the highest dry matter production in both roots and shoots of the 35‐day‐old plants was observed in plants receiving the 2/5 NH4/NO3 ratio. The same response was observed on the accumulation of soluble protein and the potential activity of PEPCase. The specific activity of PEPCase was related to the plant applications of ammonium. Treatments 3.5/3.5 and 2/5 NH4/NO3 ratio enhanced leaf GS activity between 28 and 57 days, and it was consistently 300–500% higher than root activity during the same period. Dry weight of the leaves, stems and grain showed the highest yields with those treatments at the physiological maturity of grains (105 days). 相似文献
997.
María Dolores Simón Manuel Nieves-Cordones María Jesús Sánchez-Blanco Trinitario Ferrández Manuel Nieves 《Journal of plant nutrition》2013,36(9):1466-1478
The ornamental value of plants used in semiarid areas can be improved by knowledge of their required nutrients and of their nutritional responses under saline conditions. We present a long-term study concerning the nutritional status in Chamaerops humilis and Washingtonia robusta. Two-year-old plants were grown for two years outdoors in pots using water with electrical conductivity values of 2 (control) or 8 dS m?1 (saline conditions). Nutrient specific absorption rates and leaf nutrient transport rates were estimated by fitting a Richards function regression. We suggest fertilizing C. humilis and W. robusta plants with nitrogen (N): phosphorus pentoxide (P2O5): dipotassium oxide (K2O) ratios of 4:1:5 and 5:1:3, respectively. Diagnosis and Recommendation Integrated System (DRIS) and Plant Analysis with Standardized Scores (PASS) norms were also evaluated. PASS norms provided better nutritional diagnosis than DRIS norms. In saline conditions, PASS-INI (Independent nutrient index) pointed to a deficiency (10) of phosphorus in C. humilis and of nitrogen in W. robusta. 相似文献
998.
Higher greenhouse tomato (Lycopersicon esculentum Mill.) yield is obtained by using 25% of NH4‐N in solution compared to using NO3‐N as the sole nitrogen (N) source. However, blossom‐end rot (BER) may occur in tomato fruit when NH4‐N was present in nutrient solutions. High nutrient solution strengths improve tomato fruit quality, but can also increase BER. Two NH4‐N concentrations in solution (0 and 25%), and two nighttime solution strengths (NSS) (1X and 4X Steiner solution strength applied at 7 p.m.) were used to grow five indeterminate type greenhouse tomato cultivars: Caruso, Jumbo, Match, Max, and Trust. A significant interaction occurred between NH4‐N concentration and NSS factors: 0% NH4‐N and high NSS increased marketable yield and fruit:whole plant ratio, and reduced BER. In contrast, a concentration of 25% NH4‐N and high NSS reduced marketable yield and the fruit:whole plant ratio, and increased BER incidence. Max, Match, and Trust tomato cultivars produced high marketable yield and high dry weight of stem and leaves, but were susceptible to BER. Use of NH4‐N in solution reduced vegetative growth, and high NSS increased stem and leaf dry weight of the tomato plants. Fruit firmness was greater for the Max cultivar, and was unaffected by NH4‐N and NSS at the mature green, breaker, and red ripe fruit development stages. However, at the fully ripe stage, fruit firmness was higher with high NSS and with 25% NH4‐N. 相似文献
999.
Esteban Alcántara Manuel D. de la Guardia Inmaculada Montilla Francisco J. Romera 《Journal of plant nutrition》2013,36(12):2245-2255
The initial objective was to confirm evidence, obtained from field grown plants, for iron (Fe) accumulation in leaves under ozone exposure. Tobacco plants were grown in pots under either open air or growth chamber conditions. The ozone-sensitive cultivar Bel W3 showed symptoms of ozone injury only when grown outside, while the cultivar Virginia never developed symptoms. In both cultivars, basal leaves of plants grown outside had higher concentration of Fe, but not of manganese (Mn) or zinc (Zn), than those from the growth chamber. Results suggest an interference of the oxidative stress with the mechanisms regulating Fe homeostasis. A second objective was to test whether differences in tolerance to ozone correspond with differences in tolerance to Fe toxicity. Iron toxicity was induced by supplying an excess of Fe-EDTA to plants, grown hydroponically in a growth chamber, upon partial root cutting. Symptoms in leaves were more severe in Bel W3 than in Virginia, which suggested that mechanisms of tolerance to ozone were also effective against Fe toxicity. In both cultivars, a good correlation was determined between Fe accumulation and ethylene production in the leaves. 相似文献
1000.
Guillermo Riesco Muñoz Andrés Remacha Gete Manuel Gasalla Regueiro 《Annals of Forest Science》2013,70(7):695-706