摘要:

Studien zur Stickstoffverteilung durch Emissions‐Spektrometric in freien Aminosäuren und Amiden junger ReisrispenDie Verteilung von Ammonium‐ und Nitrat‐Stickstoff auf die freien Aminosäuren und Amide junger, sich entwickelnder Reisrispen (Oryza sativaL.) wurde nach Aufnahme durch die Wurzeln ermittelt. Dabei erfolgten die Auftrennungen der Aminosäuren und Amide durch Dünnschicht‐Chromatographie und die15N‐Bestimmungen mit Hilfe der Emissions‐Spektrometrie. In den Reisrispen fanden sich große Reserven an Asparagin, Glutamin und Glutaminsäure. Die15N‐Anteile in freien Aminosäuren und Amiden waren bei Zufuhr von15N‐Ammoniumionen höher als bei entsprechender Ernährung mit Nitrat. Glutaminsäure enthielt einen wesentlich höheren Anteil an15N‐ und an Gesamt‐Stickstoff als jede andere Aminosäure, was als Hinweis auf die zentrale Bedeutung der Glutaminsäure für die Synthese der übrigen Aminosäuren aufgefaßt wurde. Allgemein waren für Aminosäuren, die primär oder sekundär im Krebs‐Zyklus entstehen, hohe Einbauraten festzustellen, und Aminosäuren mit niedrigem metabolischen turn‐over zeigten geringeren Einbau; dies gilt sowohl

ISSN:0044-3263    

DOI:10.1002/jpln.19761390502

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

Calcium content in fruits of paprika, bean, quince and hip during fruit growthThe Ca content and the Ca translocation into the fruits during their growth was determined in paprika and bean under controlled conditions (nutrient solution, growth room) and in quince and hip (Rosa rugosa Thumb.) under field conditions.Compared to leaves the Ca content in the fruits is very low in all 4 species and declines further during their growth. The K content, however, is similar in the leaves and in the fruits of all 4 species and remains nearly constant during fruit growth. The low Ca content of the fruits cannot directly be related to the cation exchange capacity (CEC) as there are no differences in the CEC between leaves and fruits.The generally low Ca content of the fruits and its decline during fruit growth is causally related in all 4 plant species to the low rate of Ca translocation compared to the rate of dry matter translocation into the fruits.There are, however, distinct differences between the 4 plant species in the course of the ratio Ca/dry matter translocation into the fruits: In paprika the Ca translocation into the fruits strongly declines during fruit growth and in bean the Ca translocation practically ceases with the onset of seed growth. In quince under field conditions the Ca translocation into the fruits rapidly declines at later stages and finally a translocation of Ca out of the fruit takes place (decrease in the amount of Ca/fruit). Only in hip the Ca translocation into the fruits remains constant during fruit growth. There is, however, a distinctly different distribution of Ca to the various parts within the hip fruits.The decline in Ca translocation during fruit growth can be explained in paprika and bean with a shift in water influx from the xylem (rich in Ca) to the phloem at the stage of high rates of dry matter influx into the fruit. In quince and hip, however, additional mechanisms (alternating water flux in the xylem, CEC) seem to be involved in the regulation of the Ca content of these fruits.

ISSN:0044-3263    

DOI:10.1002/jpln.19761390503

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

Effect of external and internal factors on the calcium content of paprika and bean fruitsIn water culture experiments with paprika and bean plants the effect of Ca supply, transpiration and growth rate on the Ca content of the fruits has been studied.A 10‐fold increase in Ca supply only slightly increased the Ca content. The Ca content of the paprika fruits was increased considerably at high transpiration rates of either the whole shoot or the single fruit. High transpiration also increased the Mg content but had no effect on the K content. In bean high transpiration rates only increased the Ca content in the early stages of fruit development.The ratio of Ca translocation versus water loss by transpiration sharply declined during fruit growth in both species. In paprika the highest ratio (μg Ca/ml) in the fruits corresponded with the ratio in the leaves. In bean fruits, however, this ratio distinctly exceeded that of fully developed leaves.At high transpiration rates of the shoot 20% of the Ca (45Ca) injected into the fruit were translocated out of the fruit. At low transpiration rates of the shoot the corresponding value was below 1%.Most of all the growth rate of the fruits affected the Ca content. With increasing growth rate the Ca transport into the fruits was hardly altered which in turn led to a sharp decrease of the Ca content per unit dry weight.The results support the idea of the Ca transport into the fruit via the xylem. This Ca transport — i.e. also the Ca content of the fruit — is regulated and is also to be influenced by direct or indirect alterations of the water transport in the

ISSN:0044-3263    

DOI:10.1002/jpln.19761390504

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

Differences in weathering and translocation between several elements in soils formed from Bärhalde‐granite including element balancingBraunerde and iron‐humus podzol profiles formed from granitic scree under the cool‐humid climate of the higher elevations of the Black Forest (SW‐Germany) were analyzed in elements of major importance in soil formation. Their content in the 2–20 mm fragments and<2 mm soil was compared with the parent rock.Na was lower in the 2–20 mm fragments and in the<2 mm soil, compared with the parent rock data. Fe, Al, Mn, Ti were reduced in the 2–20 mm fragments but enriched in the<2 mm soil. K shows in the Braunerde profiles higher contents in the fragments than in the parent rock, but lower contents in the<2 mm soil. The podzol profiles had lower K contents in both fragments and soil. Si is enriched in the 2–20 mm fragments of all analysed profiles. These differences in the behaviour during soil formation are explained by element‐selective weathering of the primary minerals.Element translocations in the soil profiles were balanced. The calculations demonstrated a strong decrease in Na in all soils, a clear decrease of Al and Mn in the podzol profiles, and decrease of Fe only in the upper soil of the podzol profiles.The queue of mobility runs: Na

ISSN:0044-3263    

DOI:10.1002/jpln.19761390505

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

A device for the irrigation of soil columnsAn irrigation device was designed for maintaining a constant water flow in soil columns over a long period of time. The apparatus consists of three construction elements: A balance for the dosage of the water, a sprinkler to distribute the water on the soil surface and an electronic time control to adjust different time steps. The wide range of possible rain intensities is shown. The mean variation of the water pulses and their distribution over the surface are discussed. The apparatus exhibits good results in long duration experiments.

ISSN:0044-3263    

DOI:10.1002/jpln.19761390506

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

Determination of wetting angles on different particle and aggregate size fractionsWith investigations of water tension, capillary rise and infiltration the wetting angles of soil are usually assumed to be zero degrees. This assumption however is very often not valid.The estimation of wetting angles in soils of different grain‐size distribution must take into account the interaction of grain‐sizes with pore sizes. Therefore a correcting factor was worked out using 12 separated grain fractions. This factor effectively eliminated the influence of grain‐size distribution when applied to fractions in the range between 2000 and 35 μm at angles between 0 and ˜90°. Some examples of results a

ISSN:0044-3263    

DOI:10.1002/jpln.19761390507

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

Homogeneity, inhomogeneity and equality of soil bodiesAn attempt is made at defining homogeneity, inhomogeneity and equality of soil bodies. A body of soil is called homogeneous if — when separated into partial units smaller than the smallest analytically assessable unit of volume — there is agreement in all properties. Any differences of properties between these partial units signify inhomogeneity. Natural soils are inhomogeneous per se. Inhomogeneity is an inherent property with specific differences between soils. In accordance to this definition it is not very meaningful to test for homogeneity, but rather to quantify the extent of inhomogeneity.Inhomogeneity can be evaluated by the following parameters:1.Variability: The variance between partial units of a body of soil. Variance is specific to the property evaluated and to the soil under investigation and is closely dependent on the volume of the partial units.2.The deviation from the ideally statistical arrangement (AviA): Partial units may, in respect to their local connection, be combined to larger volume units, which possess more similar properties within than between each other. These fields of similarity in turn form superior units in form, volume and pattern, which are called pattern complexes. Several such pattern complexes are superimposed in soil bodies.Soil investigations can only assess a limited section of the total inhomogeneity. Volume of sample, intensity of sampling and method of selection must be adequate to the type of research.Partial units of soil bodies are equal (or comparable) if their inhomogeneity does not exceed a preset limit specific to the objectives of the investigat

ISSN:0044-3263    

DOI:10.1002/jpln.19761390508

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

A method for bulk density determination of gravel rich or thin soil horizonsA limitation of bulk density determinations using the core sample method is that soil horizons must be thick enough for coring and nearly free of rock material. The significance of the proposed method lies in the fact that it is applicable also to soil samples rich in rock fragments and/or thin horizons. The samples are impregnated in the laboratory using an epoxy resin. Bulk density (ρb) is determined after hardening according to the following equation:ρf= density of soil material Bulk densities determined by the new method were found to agree well with such resulting from the core sample metho

ISSN:0044-3263    

DOI:10.1002/jpln.19761390509

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

Principles for construction of soil classification systemsSoil classification systems have to be constructed by induction and deduction or in a mixed manner, leading to classes of isogeneous and isomorphous soils, which are based on the criteria of affinity or similarity, respectively. By adding the criteria of effect and neighbourhood classes of isofunctional and isotopic soils are formed. The theoretical basis for these classifications is given by the chain of causality for pedogenesis and pedofunction:A general model for constructing traditional und numerical soil classification systems is proposed, which allows the analysis of existing systems or the construction of new ones.

ISSN:0044-3263    

DOI:10.1002/jpln.19761390510

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

Effect of varied N‐fertilization on assimilation rate and yield of spring wheatIn pot experiments with spring wheat the effect of a variied N‐fertilization on yield and assimilation rate was studied by the use of14CO2.The assimilation rate per pot increases during the vegetative period in both years till the time short before flowering, followed by a decrease towards the end of experiment.Increased N‐supply results only in a small increase of total assimilation per pot, but in the young leaves of high nitrogen plants the assimilation was enhanced.N‐fertilization has a pronounced effect on the loss of assimilated14C due to respiration. Plants with high N‐supply lost 20%, those with low N‐supply 50% of the14C assimilated during the period of emergence of ears.The different yields of plants with variied N‐supply are not primarely the result of an altered assimilation rate, but of the different loss due t

ISSN:0044-3263    

DOI:10.1002/jpln.19761390511

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY