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Nitrogen Application (nitrogen + application)
Selected AbstractsFluctuation of Vegetative Storage Proteins in the Seedlings of Swietenia macrophylla, Analogous to the Seasonal Changes of Those in the Shoot of the Adult TreeJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 3 2007Ya-Qin Han Abstract In order to identify appropriate plant materials for studying the gene expression and biological function of vegetative storage proteins (VSPs) in woody plants, the VSPs in the seedlings of Swietenia macrophylla King were investigated by using light microscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western-blotting. The seed of S. macrophylla was rich in storage proteins that accumulated in the vacuoles of cotyledon parenchyma cells in appearance of compact spherical grains. The growth and development of S. macrophylla seedlings were characterized by an obvious growth rhythm. The storage proteins in seeds disappeared during seedling growth while VSPs appeared in the stem 2 weeks after seedling leaves matured. Thereafter, the VSPs in the seedling stem almost exhausted during new shoot growth, and when the leaves of new shoot just matured, both the stem beneath the new shoot of seedlings and the stem of new shoot started to accumulate VSPs. Nitrogen application dramatically increased the level of VSPs, but had little influence on the dynamics of VSP consumption and accumulation in seedling stem. Together with these data, the fluctuation of VSPs in seedlings was very similar to that in the branches of the adult trees. In addition, seedlings are easy to be treated due to their small size. Our results suggested that S. macrophylla seedlings were suitable for investigating the biological roles of VSPs and the mechanism of nitrogen storage in trees. [source] Root colonisation by the arbuscular mycorrhizal fungus Glomus intraradices alters the quality of strawberry fruits (Fragaria × ananassa Duch.) at different nitrogen levelsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2010Vilma Castellanos-Morales Abstract BACKGROUND: Arbuscular mycorrhizal fungi (AMF) increase the uptake of minerals from the soil, thus improving the growth of the host plant. Nitrogen (N) is a main mineral element for plant growth, as it is an essential component of numerous plant compounds affecting fruit quality. The availability of N to plants also affects the AMF,plant interaction, which suggests that the quality of fruits could be affected by both factors. The objective of this study was to evaluate the influence of three N treatments (3, 6 and 18 mmol L,1) in combination with inoculation with the AMF Glomus intraradices on the quality of strawberry fruits. The effects of each factor and their interaction were analysed. RESULTS: Nitrogen treatment significantly modified the concentrations of minerals and some phenolic compounds, while mycorrhization significantly affected some colour parameters and the concentrations of most phenolic compounds. Significant differences between fruits of mycorrhizal and non-mycorrhizal plants were found for the majority of phenolic compounds and for some minerals in plants treated with 6 mmol L,1 N. The respective values of fruits of mycorrhizal plants were higher. CONCLUSION: Nitrogen application modified the effect of mycorrhization on strawberry fruit quality. Copyright © 2010 Society of Chemical Industry [source] Does soil nitrogen influence growth, water transport and survival of snow gum (Eucalyptus pauciflora Sieber ex Sprengel.) under CO2 enrichment?PLANT CELL & ENVIRONMENT, Issue 5 2009BRIAN J. ATWELL ABSTRACT Eucalyptus pauciflora Sieber ex Sprengel. (snow gum) was grown under ambient (370 µL L,1) and elevated (700 µL L,1) atmospheric [CO2] in open-top chambers (OTCs) in the field and temperature-controlled glasshouses. Nitrogen applications to the soil ranged from 0.1 to 2.75 g N per plant. Trees in the field at high N levels grew rapidly during summer, particularly in CO2 -enriched atmosphere, but suffered high mortality during summer heatwaves. Generally, wider and more numerous secondary xylem vessels at the root,shoot junction in CO2 -enriched trees conferred fourfold higher below-ground hydraulic conductance. Enhanced hydraulic capacity was typical of plants at elevated [CO2] (in which root and shoot growth was accelerated), but did not result from high N supply. However, because high rates of N application consistently made trees prone to dehydration during heatwaves, glasshouse studies were required to identify the effect of N nutrition on root development and hydraulics. While the effects of elevated [CO2] were again predominantly on hydraulic conductivity, N nutrition acted specifically by constraining deep root penetration into soil. Specifically, 15,40% shallower root systems supported marginally larger shoot canopies. Independent changes to hydraulics and root penetration have implications for survival of fertilized trees under elevated atmospheric [CO2], particularly during water stress. [source] The economic potential of precision nitrogen application with wheat based on plant sensingAGRICULTURAL ECONOMICS, Issue 4 2009Jon T. Biermacher Nitrogen fertilizer; Precision agriculture; Stochastic plateau; Wheat Abstract Plant-based precision nitrogen fertilizer application technologies have been developed as a way to predict and precisely meet nitrogen needs. Equipment necessary for precision application of nitrogen, based on sensing of growing wheat plants in late winter, is available commercially, but adoption has been slow. This article determines the expected profit from using a plant-sensing system to determine winter wheat nitrogen requirements. We find that plant-sensing systems have the potential to be more profitable than traditional nonprecise systems, but the existing system simulated was roughly breakeven with a traditional system. [source] Glycosidases in soils as affected by cropping systemsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 6 2005Daniel E. Dodor Abstract Glycosidases are a group of soil enzymes that play a major role in degradation of carbohydrates. This study was conducted to assess the impact of crop rotation and N fertilization on the activities of ,- and ,-glucosidases and ,- and ,-galactosidases in plots of two long-term field experiments at the Clarion-Webster Research Center (CWRC) and Northeast Research Center (NERC) in Iowa. Surface-soil (0,15 cm) samples were taken in 1996 and 1997 in corn (Zeamays L.), soybean (Glycinemax (L.) Merr.), oats (Avenasativa L.), or meadow (alfalfa) (Medicago sativa L.) plots that received 0 or 180,kg N ha,1, applied as urea before corn, and an annual application of 20,kg P ha,1 and 56,kg K ha,1. Activities of the four glycosidases were significantly affected by crop rotations in both years at the two sites but not by nitrogen application. In general, higher activities were observed in plots under meadow or oat and the lowest in continuous corn (CWRC) and soybean (NERC). Four-year rotation showed the highest activity, followed by 2-year rotation and monocropping systems. Linear-regression analyses indicated that, in general, the activities of the glycosidases were significantly correlated with microbial-biomass C (r > 0.302, p , 0.05) and microbial-biomass N (r > 0.321, p , 0.05), organic-C (r > 0.332, p , 0.05) and organic-N (r > 0.399, p , 0.01) contents of the soils. Results of this work suggest that multicropping stimulated the activities of the glycosidases. The specific activities of the glycosidases in soils of the two sites studied, expressed as g p -nitrophenol released per,kg of organic C, differed among the four enzymes. The lowest values were obtained for ,-galactosidase and ,-glucosidase, followed by ,-galactosidase and ,-glucosidase. Glycosidasen in Böden unter dem Einfluss von Bewirtschaftungssystemen Glycosidasen stellen eine Gruppe von Bodenenzymen dar, welche eine entscheidende Rolle im Abbau von Kohlenhydraten spielen. Ziel dieser Untersuchungen war die Erfassung des Einflusses von Fruchtfolge und N-Düngung auf die Aktivitäten von ,- und ,-Glucosidasen und ,- und ,-Galactosidasen in zwei Langzeitfeldversuchen, dem Clarion-Webster-Versuchsfeld (CWRC) und dem Northeast-Versuchsfeld (NERC) in Iowa. In den Jahren 1996 und 1997 wurden Oberbodenproben (0,15 cm) von Parzellen unter Mais (Zeamays L.), Sojabohne (Glycine max (L.) Merr.), Hafer (Avena sativa L.) oder Luzerne (Medicago sativa L.) entnommen, welche vor Mais 0 oder 180,kg N ha,1 in Form von Harnstoff sowie jährliche Düngergaben in Höhe von 20,kg P ha,1 und 56,kg K ha,1 erhielten. Über zwei Jahre wurden die Aktivitäten der vier Glycosidasen in beiden Feldversuchen signifikant von der Bewirtschaftung beeinflusst, jedoch nicht von der N-Düngung. Im allgemeinen wurden höhere Enzymaktivitäten in Parzellen unter Luzerne oder Hafer festgestellt und die geringsten unter Maismonokultur (CWRC) bzw. Sojabohne (NERC). Vierjährige Fruchtfolgen zeigten die höchsten Aktivitäten, gefolgt von zweijährigen Fruchtfolgen und Monokulturen. Analysen mittels linearer Regression weisen auf eine Korrelation zwischen Glycosidaseaktivitäten und C (r > 0.332, p , 0.05) und N der mikrobiellen Biomasse (r > 0.321, p , 0.05) sowie den Gehalten an org. C (r > 0.332, p , 0.05) und N (r > 0.399, p , 0.01) hin. Die Ergebnisse dieser Untersuchungen deuten darauf hin, dass die Aktivitäten von Glycosidasen durch mehrjährige Fruchtfolgen stimuliert wurden. Die spezifischen Glycosidaseaktivitäten in den Böden der zwei Feldversuche, berechnet als freigesetztes p -Nitrophenol (g (kg org. C),1), variierten zwischen den vier Enzymen. Die geringsten Werte wurden für ,-Galactosidase und ,-Glucosidase festgestellt, gefolgt von ,-Galactosidase und ,-Glucosidase. [source] The effects of differentiated water supply after anthesis and nitrogen fertilization on ,15N of wheat grainRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 3 2010Ivana Raimanová The ,15N signature of plants integrates various processes in soil and plant. In this study, the effect of different water regimes applied during the period of grain growth of winter wheat on grain ,15N was examined in a 4-year field experiment. The treatments comprised water shortage (S), an ample water supply (W), and rain-fed crop (R). Zero fertilization (N0) and 200,kg,N.ha,1 in mineral fertilizer (N1) treatments were studied. The grain 15N was determined during grain growth and at maturity. The water regime, nitrogen application and year had a significant effect on mature grain ,15N (p,<,0.001). Water and nitrogen explained 54.6% of the variability of ,15N in the experiment, the year accounted for 10.7% and the interactions for another 19.6% of the total variability. The analysis of non-mature grain ,15N showed significant effects of N and year but not of water. Nitrogen fertilization reduced the ,15N of mature grain in years by 0.7,6.3, in comparison with N0 plants; the reduction was more pronounced under stress (average reduction by 4.1,) than under rain-fed (2.4,) and ample water supply (2.2,). Water stress decreased the grain ,15N in fertilized wheat, by 0.1,2.1, and 0.6,3.6, in experimental years, on average by 1.30, and 1.79, in comparison with the R and W water supply, respectively. The effect of water supply was not significant in non-fertilized wheat. A significant negative linear relationship between grain N concentration and ,15N in maturity or during the grain growth (R2,=,0.83, R2,=,0.76, respectively) was found. The observed sources of grain ,15N variability should be taken into consideration when analyzing and interpreting the data on the ,15N signature of plant material from field conditions. Copyright © 2010 John Wiley & Sons, Ltd. [source] The effects of organic and inorganic fertilizer applications to Miscanthus×giganteus, Arundo donax and Phalaris arundinacea, when grown as energy crops in Wales, UKGCB BIOENERGY, Issue 4 2010R. SMITH Abstract Two pot trials and one field trial were established to investigate the effects of organic and inorganic fertilizer applications to energy crops grown in mid-Wales. Chicken litter and sewage cake applied at a high level in excess of MAFF recommendations produced an increased yield response in Miscanthus and Arundo plants. Miscanthus plants exhibited an increased growth response to all fertilizers applied in its second year. Fertilizer applications in accordance with MAFF recommendations produced no significant differences in yields for Miscanthus or Arundo potted plants. In the field there was an increased yield response of Miscanthus to inorganic nitrogen applications compared with organic manures, but not with control plots. Analysis of the Miscanthus plant material at harvest showed significant differences in the nitrogen, potassium and copper content between treatments. No mineral content differences were shown for Miscanthus rhizome material or Arundo plant material. The Phalaris plants did not exhibit significant differences in growth or yield parameters, but their plant matter showed differences in nitrogen, phosphorus, potassium, calcium, sulphur and boron content between treatments. [source] Long-term influence of manure and mineral nitrogen applications on plant and soil 15N and 13C values from the Broadbalk Wheat Experiment,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2008Mehmet Senbayram The Broadbalk Wheat Experiment at Rothamsted Research in the UK provides a unique opportunity to investigate the long-term impacts of environmental change and agronomic practices on plants and soils. We examined the influence of manure and mineral fertiliser applications on temporal trends in the stable N (15N) and C (13C) isotopes of wheat collected during 1968,1979 and 1996,2005, and of soil collected in 1966 and 2000. The soil ,15N values in 1966 and 2000 were higher in manure than the mineral N supplied soil; the latter had similar or higher ,15N values than non-fertilised soil. The straw ,15N values significantly decreased in all N treatments during 1968 to 1979, but not for 1996,2005. The straw ,15N values decreased under the highest mineral N supply (192,kg,N,ha,1,year,1) by 3, from 1968 to 1979. Mineral N supply significantly increased to straw ,13C values in dry years, but not in wet years. Significant correlations existed between wheat straw ,13C values with cumulative rainfall (March to June). The cultivar Hereward (grown 1996,2005) was less affected by changes in environmental conditions (i.e. water stress and fertiliser regime) than Cappelle Desprez (1968,1979). We conclude that, in addition to fertiliser type and application rates, water stress and, importantly, plant variety influenced plant ,13C and ,15N values. Hence, water stress and differential variety response should be considered in plant studies using plant ,13C and ,15N trends to delineate past or recent environmental or agronomic changes. Copyright © 2008 John Wiley & Sons, Ltd. [source] | |||||||||||||