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排序方式: 共有110条查询结果,搜索用时 18 毫秒
71.
72.
Joséphine Semaan Guillermo Flichman Alessandra Scardigno Pasquale Steduto 《Agricultural Systems》2007
Nitrate leaching is one of the many forms of environmental pollution resulting from irrigation and intensive agriculture. In this work, a method of combining an agronomic simulation model (EPIC) and a mathematical multi-objective programming model is used to analyse the effects of three agricultural policies on farmer’s revenue and nitrate leaching. An evaluation of the net social costs associated with the different policy measures is also given. The farmer’s behaviour in different policy scenarios was studied in terms of selected crops, irrigation technique and method, and adopted management practices with focus on farm management practices and water application efficiency. Irrigation water pricing, subsidies to adopt improved management levels, and taxation on the use of nitrogen fertilizer were examined. A trade-off emerges between the levels of nitrate leaching and net farmer’s revenue more pronounced for nitrogen tax policies than for water pricing. The results obtained indicate that nitrate leaching can be reduced by about 40% with an associated net social cost of 269 €/ha for the water pricing policy, 183 €/ha for the tax on fertilizer and 95 €/ha for subsidies to high efficiency management. 相似文献
73.
Resource use efficiency of field-grown sunflower, sorghum, wheat and chickpea: I. Radiation use efficiency 总被引:2,自引:0,他引:2
Radiation use efficiency () is a crop parameter widely used in crop simulation models, derived here as the slope of the relationship linking crop carbon gain to cumulative intercepted solar radiation. Our objectives were to: (i) determine of field-grown sunflower, sorghum, wheat and chickpea, at three levels of aggregation—day-time net assimilation (A), daily net carbon gain as difference between A and night-time dark respiration (R) and biomass; (ii) assess the robustness of parameter in terms of ability to discriminate between C3 and C4 species, pre- and post-anthesis and impact of nitrogen status; (iii) evaluate the opportunity to normalize for climate. Field experiments were conducted in 1998 and 1999 in southern Italy. All crops were well watered. Sunflower and sorghum had two nitrogen application treatments, wheat only one and chickpea had no added nitrogen. Daily intercepted solar radiation was derived from measurements of daily incident solar radiation and the percentage of mid-day light interception. Closed-system canopy chambers monitored canopy gas-exchange rates. , expressed in terms of A, A − R or above-ground biomass, was linear over the entire growth cycle of sorghum and wheat, and up to anthesis in sunflower and chickpea, independent of temperature, vapour pressure deficit and radiation regimes. In sunflower, deviation from linearity was observed after anthesis, due to higher carbon cost in yielding oil seeds. No conclusions could be drawn for post-anthesis chickpea due to the interruption of the experiment caused by a thunderstorm. Overall results showed a great variability in values, independently of classes of species (C4 and C3), crops and nitrogen treatments. This indicates that the robustness of to predict biomass productivity in crop simulation models is constrained. Attempts to normalize by vapour pressure deficit (D), for reducing its variability due to climate and overlaps between crops failed. 相似文献
74.
Valeria Terzi Caterina Morcia A. Michele Stanca Ladislav Kucera Clara Fares Pasquale Codianni Natale Di Fonzo Primetta Faccioli 《Genetic Resources and Crop Evolution》2007,54(7):1613-1621
In the last few years, the renewed interest for emmer wheat (Triticum dicoccon Schrank) in Italy has stimulated breeding programs for this crop releasing improved genotypes obtained not only by selection
from landraces, but even by crosses with durum wheat (Triticum durum Desf.) varieties. The purpose of this work has been to uncover the genetic make-up of some emmer × durum derivatives, specifically
by comparing the differences from their parents. Genetic diversity of advanced breeding lines and varieties derived from a
durum × emmer cross has been evaluated on the basis of AFLP and SSR markers in comparison with the corresponding emmer and
durum wheat parent for addressing the seminal question of how much ‘wild’ variation remains after selection for agronomic
type. 相似文献
75.
Evaluation of extracts and isolated fraction from Capparis spinosa L. buds as an antioxidant source 总被引:16,自引:0,他引:16
Germanò MP De Pasquale R D'Angelo V Catania S Silvari V Costa C 《Journal of agricultural and food chemistry》2002,50(5):1168-1171
The antioxidant activity of extracts from Capparis spinosa L. buds was evaluated using different in vitro tests: ascorbate/Fe(2+)-mediated lipid peroxidation of microsomes from rat liver; bleaching of 1,1-diphenyl-2-picryl-hydrazyl radical; and autoxidation of Fe(2+) ion in the presence of bathophenanthroline disulfonate. The methanolic extract showed strong activities in all of these in vitro tests. The amount of total phenols was determined in the methanolic extract. In addition, the level of rutin was calculated as 0.39% (w/w) by HPLC analysis. Our findings indicate the following: (a) the antioxidant efficiency of the methanolic extract may be attributed to its phenolic content; and (b) the antioxidant activity of the methanolic extract was maintained after removal of glucosinolates, confirming that these compounds do not interfere with the antioxidant properties of the extract. The results obtained from this study exalt the nutritional value of the flowering buds (capers) which are widely used as a source of flavor. 相似文献
76.
Maya Vetencourt JF Sale A Viegi A Baroncelli L De Pasquale R O'Leary OF Castrén E Maffei L 《Science (New York, N.Y.)》2008,320(5874):385-388
We investigated whether fluoxetine, a widely prescribed medication for treatment of depression, restores neuronal plasticity in the adult visual system of the rat. We found that chronic administration of fluoxetine reinstates ocular dominance plasticity in adulthood and promotes the recovery of visual functions in adult amblyopic animals, as tested electrophysiologically and behaviorally. These effects were accompanied by reduced intracortical inhibition and increased expression of brain-derived neurotrophic factor in the visual cortex. Cortical administration of diazepam prevented the effects induced by fluoxetine, indicating that the reduction of intracortical inhibition promotes visual cortical plasticity in the adult. Our results suggest a potential clinical application for fluoxetine in amblyopia as well as new mechanisms for the therapeutic effects of antidepressants and for the pathophysiology of mood disorders. 相似文献
77.
A. Domenico Palumbo Domenico Vitale Pasquale Campi Marcello Mastrorilli 《Irrigation and Drainage Systems》2011,25(4):395-411
This study aims to evaluate the potential effects of the climatic variations on the reference evapotranspiration (ET0) and, consequently, on the crop water requirements in the Apulian Tavoliere, one of the largest irrigated districts of Southern Italy. To reach this purpose, both climatic parameters (air temperature and rainfall) and estimated water requirements of ??processing?? tomato (among the most representative irrigated crops in the district since the mid-1970s and, therefore, chosen as a study-case) were analyzed in order to find out if a time trend exists or does not. The analysis covered the period from 1957 to 2008. The analysis showed that the rainfall amounts decreased (?3.4 mm per year in the analyzed period), while air temperature increased (0.18 °C and 0.25?°C per decade for minimum and maximum, respectively). As a consequence of the climatic variation during the considered period, a growth trend of the ET0 (1.4 mm per year) and water deficit (3.2 mm per year) took place. As a consequence, the water amounts for irrigating the same crop in the considered period were growing. This increased consumption is in agreement with the perception of the farmers of the district but never documented. Through the FAO AquaCrop model, the tomato irrigation water requirements have been simulated during the considered period. The trend analysis of the seasonal evapotranspiration values simulated in 52 years confirmed the increase in tomato water requirements (0.7 mm per year). 相似文献
78.
Romina Beleggia Cristiano Platani Franca Nigro Pasquale De Vita Luigi Cattivelli Roberto Papa 《Journal of Cereal Science》2013
The aim of this study was to assess the relative roles of genotype, environment and genotype-by-environment interactions in determining the metabolite profile of durum wheat grain. Four durum wheat cultivars were grown under conventional and organic farming systems over three consecutive years. The use of a high-throughput gas chromatography–mass spectrometry platform allowed the analysis of sets of different polar and non-polar compounds, including amino acids, sugars, organic acids, fatty acids (saturated and unsaturated), and sterols. Statistical analysis of the data showed a small impact of genotype and large effects of both year and genotype-by-environment interaction on the metabolite composition and quality of the wheat grain. Overall, the data from this study highlight the potential role of metabolic profiling in the analysis of durum wheat quality and production. 相似文献
79.
González-Rey C Svenson SB Bravo L Siitonen A Pasquale V Dumontet S Ciznar I Krovacek K 《Comparative immunology, microbiology and infectious diseases》2004,27(2):129-139
A total of 73 strains of Plesiomonas shigelloides isolated from humans (24 strains) animals (21 strains) and aquatic environment (28 strains) were determined for their O:H serotype and susceptibility to 18 anti-microbial substances and to the vibriostatic agent O/129. Of all strains, 86.3% were typeable by the O and 94.5% by the H anti-sera used. The serotype distribution was heterogeneous within a country and between the countries. Of the 57 different serotypes identified, O11:H2 (2 strains), O22:H3 (4 strains), O35:HH11 (2 strains), O52:H3 (2 strains) and O90:H6 (2 strains) were found among isolates from humans and animals (mainly in cats) in Finland and Cuba, and O23:H1a1b (3 strains) among isolates from environmental sources in Slovak Republic and Italy. Most (93-100%) of all strains were susceptible to all anti-microbials tested but resistant (92-96%) to the broad-spectrum penicillins (ampicillin, mezlocillin). No correlation between anti-microbial resistance patterns and serotypes was found. 相似文献
80.
Five clones of sour orange (Citrus aurantium L.) showing significant morphological differences were selected from our germplasm collection and characterized both by genetic and leaf volatiles analysis. The genetic studies were undertaken by the use of molecular markers developed by PCR-based techniques (ISSR and RAPD), while the leaf essential oil patterns were obtained by chromatographic and mass spectrometric determination. Data obtained suggest that reasonably similar information can be achieved from the two techniques, supporting each other in characterization studies. 相似文献