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D. Steffens 《植物养料与土壤学杂志》1984,147(1):85-97
Root studies and phosphorus uptake of rye-grass and red clover under field conditions Root parameters (fresh weight, density, surface, length, cation exchange capacity) and phosphate uptake were studied with rye grass and red clover, grown in the field on a brown podsolic soil. In all root parameters, ry grass was superior to red clover. Also, phosphate uptake of rye grass was higher than that of red clover. The greatest difference between both species was found in root length, that of rye grass being about five times longer than that of red clover. Rye grass had longer root hairs than red clover; whereas root diameter of clover was about twice as thick the average rye grass. Significant correlations were observed between root parameters and phosphate uptake in the plants studied. The highest correlation coefficients were obtained for the relationship P-uptake versus root length (clover 0.91***, grass 0.87***) and P-uptake versus root fresh weight (clover 0.92***, grass 0.88***). The phosphate uptake per unit root parameters was significantly higher in red clover, compared with rye grass, for the parameters root fresh weight, cation exchange capacity and root length. Because of this high P-uptake rate for clover it is assumed that clover also requires a higher P-concentration in soil solution as compared with grass. Thus grass may still grow with low P concentrations in the soil solution without P deficiency at which clover cannot grow. It is for this reason that in mixed swards clover is depressed by grass, if the available P in the soil is low. 相似文献
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Phosphate depletion at the soil — root interface and the phosphate uptake of maize and rape Maize and rape plants were grown in flat containers in a 33P-labelled sandy soil and the distribution of soil phosphate near roots was determined by using densitometric scans of autoradiographs. The concentration of isotopically exchangeable phosphate at the root surface decreased within a few days by 42 per cent with rape and by 50–65 per cent with maize. Initially the width of the depletion zone is very small. Within six days the depletion zone extended to the final distance from the surface of the root cylinders of about 2 mm for maize and 2.6 mm for rape. The soil within the range of the mean length of root hairs (0.7 mm for maize and 1.3 mm for rape) is almost equally depleted. This indicates that root hairs are very important for P-uptake from soil. This is further supported by higher P-uptake rates per cm root length of rape than of maize. The P-concentration of the soil solution was estimated by means of the phosphate desorption curve. Within the root hair cylinder the P-concentration of the soil solution decreased from 0.8 to 0.03 mg P/l. Changes of the P-depletion profile with time were used to calculate P-uptake rates for roots of different age. The results indicate that for the first 3–5 days P-uptake rates remained near maximum, even though the P-concentration of the soil solution at the root surface had strongly decreased within two days. Phosphate uptake rates per cm root length did not decrease unless the whole root hair cylinder had been depleted. 相似文献
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Gisela Fischer 《植物养料与土壤学杂志》1982,145(4):347-355
Microsymptoms in maize and tomatoes resulting from imbalanced nitrogen and phosphorus supply The inducing factors of visible symptoms are not easy to identify in cases of ?complex”? symptoms. ?Complex”? symptoms originate from simultaneous multiple nutrient deficiencies, nutrient deficiency and excess, or multiple nutrient toxicities. Microsymptoms are well known for nitrogen and phosphorus deficiency supply as well as for nitrogen excess supply. The aim of the present paper was to study whether these microsymptoms can be helpful in diagnosing visible symptoms which are difficult to identify in cases of ?complex”? symptoms. The experiments were carried out with maize and tomatoes under controlled experimental conditions in solution culture. Microsymptoms which occur in response to nitrogen or phosphorus stress – deficiency or excess – occur in the same way in plants that are suffering from imbalanced nitrogen and phosphorus supply. In cases of multiple toxicities further microsymptoms occurred. These symptoms mainly depended on the nutrient concentration in the solution. 相似文献
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G. Fischer 《植物养料与土壤学杂志》1981,144(5):431-440
Macrosymptoms in higher plants resulting from imbalanced nitrogen and phosphorus supply The development of nitrogen and phosphorus deficiency and toxicity symptoms was studied under controlled experimental conditions in solution culture. The experiments were carried out with maize and tomato. The aim of the investigation was to study whether the macrosymptoms of nitrogen deficiency or toxicity in its typical form are influenced by simultaneous phosphorus deficiency or excess supply, or, on the other hand, whether the typical symptoms of phosphorus deficiency or excess are affected by simultaneous nitrogen deficiency or excess supply. The results show that - assuming that ‘complex’ symptoms occur - neither nutrient influences the development of macrosymptoms in their typical form as caused by the other nutrient. Tomato showed clear ‘complex’ symptoms while maize only showed the macrosymptoms of one nutrient. 相似文献
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Zusammenfassung Der Pigmentgehalt von zwei Hybridtomatensorten Nr. 10 × Bison und Sarja × Komet und von deren Eltern Nr. 10, Bison, Sarja und Komet wurde bestimmt. Die Blätter der Bastarde Nr. 10 × Bison sowie Sarja × Komet führten höhere Chlorophyll a-, Chlorophyll b-, Carotin- und Xanthophyllmengen als diejenigen ihrer Ausgangsformen. Der Phaeophytingehalt lag bei den Hybridformen immer niedriger (zum Teil viel niedriger) als bei den Eltern.
Zentralwissenschaftliches Institut für Gemüsekulturen Mariza bei Plovdiv (Bulgarien). Die Arbeit wurde während eines Gastaufenthaltes am Institut für Pflanzenzüchtung der DAL Quedlinburg und am Institut für Kulturpflanzenforschung der DAW zu Berlin in Gatersleben durchgeführt. 相似文献
Summary The pigmentation of two hybrid varieties fromLycopersicon esculentum Nr. 10 × Bison and Sarja × Komet and their parents Nr. 10, Bison, Sarja and Komet, was determined. The leaves from the bastards Nr. 10 × Bison and Sarja × Komet had more Chlorophyll a, Chlorophyll b, Carotin and Xanthophyll than those from their parents. The content of Phaeophytin was in the hybridforms lower (partly much lower) than in the parents.
, 10 × × , . a, b, , . ( ) .
Zentralwissenschaftliches Institut für Gemüsekulturen Mariza bei Plovdiv (Bulgarien). Die Arbeit wurde während eines Gastaufenthaltes am Institut für Pflanzenzüchtung der DAL Quedlinburg und am Institut für Kulturpflanzenforschung der DAW zu Berlin in Gatersleben durchgeführt. 相似文献
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Theodor Weichelt 《植物养料与土壤学杂志》1982,145(6):561-566
Methoxyl content, PSR and color reactions on root and straw lignin The wet chemical measured content of methoxyl groups is in lignin from up to 13 cm long roots and straw with ～ 11,5 % nearly indentical. Lignin in roots contains more keto groups. This was proved by psr-spectroscopy (δ = 8 ppm) and by various color reaction with o–dianisidine/HCl, diphenylamine, acridine, barbituric acid, p-anisidinhydrochloride, sulfanilic acid and aniline. Root lignin has also more benzolic protons (δ = 5,35 – 5,45 ppm) and by far higher part of highly shielded aliphatic protons (δ = 1,33 ppm). The last diminished to a large extend after having react with diazomethane. From this informations could even be concluded that lignin in roots has more methylable structures. Against that protons in the side arms are to find more in the lignin of straw. 相似文献
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Comparison of German and Swiss Rainfall Simulators - Rain Structure and Kinetic Energy The drop size distributions of the investigated rain are significantly different. The rainfall simulators Swanson, Bonn, Basel and Trier culminate in the 2 - 3 mm drop diameter class (～40%) and thus simulate best the drop size distribution of natural heavy rainfall. The structure and the kinetic energy of the rains of eight rainfall simulators have been investigated. The data are compared to those registered during a thunder-shower at the research station of Mertesdorf near Trier/FRG. The results are summarized as follows:
- The impact velocity of artificial raindrops depends on the water pressure within the rainfall simulator, the initial velocity of the raindrops and the fall height. A correction factor to match the kinetic energy of natural rainfall, which is based on the percentage of deviation from the terminal velocity, can be applied only to some extend.
- With respect to various fall velocities of the artificial raindrops all tested rainfall simulators except one yield a rainfall energy between 19 and 27 J/m2 per mm of rainfall.
- The actual amount of precipitation measured at the end of the rainfall experiments sometimes differs significantly from the aimed value of 60 mm/h. Due to this variation, the total rainfall energy during the experiments accumulated to 9 - 15 MJ/ha.
- This high variability depends on the used rainfall simulator. But it also demonstrates the importance of precipitation measurements on the plot during simulations in order to exactly calculate the rainfall energy.
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Effect of NaCl and Na2SO4 on dry matter production, mineral content and organic compounds of spinach and lettuce . In water culture experiments the effect of 2,5 meq and 25 meq NaCl and Na2SO4 respectively on dry matter production and content of mineral elements, chloroplasts pigments and carbohydrates in lettuce (salt sensitive) and spinach (salt tolerant) has been studied. With increasing Na-supply the dry matter production was decreased in lettuce and increased in spinach. With increasing Na-supply in both species the content of K, Mg and Ca in the leaves decreased. This decrease was more pronounced with sulfate as accompanying anion (Na2SO4) and induced already deficiency in Ca and Mg. This induced deficiency of Mg was reflected especially in lettuce in lower contents of chloroplasts pigments. In both plant species there was no effect of the Na salt treatments on the content of phosphorus or nitrogen in roots or leaves. The carbohydrate content in both species was strongly affected by the Na salt treatments. Irrespectively of the accompanying anion this effect occured already at the low Na supply and before the dry matter production was influenced. In leaves and roots of lettuce the contents of glucose, fructose and sucrose was considerably decreased; this decrease was less expressed in the starch content. In spinach the Na supply only decreased the carbohydrate content in the roots whereas in the leaves especially the sucrose content was increased. This different effect of Na on carbohydrate content in spinach and lettuce could be an indication of different action of Na on carbohydrate metabolism, namely inhibited synthesis in lettuce and inhibited translocation in spinach. The results demonstrate that in studies on the effect of increasing Na salt concentrations besides the osmotic effects also the ion specific effects have to be carfully considered. These ion specific effects are competition of Na+ with other cations during uptake and the influence of Na on the cell metabolism, especially on the pathway of carbohydrates. The authors thanks Mrs. Hwie Juen Tjandraatmadja for her engaged help in various laboratory works. 相似文献
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The influence of Mg- and Ca-deficiency on the micromorphology of epicuticular waxes and on the wettability of spruce needles The influence of Mg- and Ca-deficiency in nutrient solution on epicuticular waxes of needles of Norway spruce (Picea abies [L.] Karst.) was investigated in greenhouse experiments. Spruce clones were cultivated in sand and supplied with nutrient solution. For two vegetation periods, plants of the treatment groups -Mg, -Ca and -Mg/-Ca were provided with only 15 % of the respective mineral element of the control. At the end of the second vegetation period, the nutrient deficiency was documented by reduced Mg- and/or Ca-content of the needles and changes in chlorophyll fluorescence. No effect on micromorphology of epicuticular waxes and wettability of needles of any age was observed following deficient Mg and/or Ca supply. 相似文献
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Karl-Ulrich Brosche 《CATENA》1977,3(3-4)
Seven multisectional profiles are described, taken mainly from loess soils and loess-like sediments in Northwest Spain, Central Spain, Southeast Spain and the South of France. The silty sediment sequences all show several soil formations, developed to varying extents In addition, a terrace profile with silty surface layers (Ciempozuelos, south of Madrid) and a terrace profile with silty inter-layers (Arobes, near Ribadesella) were found. Because of their morphological situation, their strata sequence and facies, we have classified the profiles as upper and middle Pleistocene. This is based on the hypothesis that climatic variations and the resulting pedogenetic superimpositions of the sediments behaved similarly to those in Central Europe. Our chronological classifications - apart from the profile in Tapia de Casariego in NW Spain - should be understood as suggestions, which do not preclude the possibility that new findings may make revision necessary. The profile at Tapia de Casariego, however, exhibits many similar features to the Central European Würm-Eem standard profile. 14C-dates do not contradict this statement.In addition, views are expressed on the question of the origin of the loess and the medium of transport. Consideration is given to the Holocene surface soils, as well as to the climatic preconditions which come into question in the formation of paleosoils in the study area.
Zusammenfassung
Es werden sieben mehrgliedrige Profile vornehmlich in Lössen und lößartigen Sedimenten aus NW-Spanien, Zentralspanien, Südostspanien und Südfrankreich beschrieben. Die Sedimentabfolgen mit schluffigem Charakter weisen alle mehrere unterschiedlich intensiv ausgeprägte Bodenbildungen auf. Es konnte ferner ein Terrassenprofil mit schluffigen Deckschichten (Ciempozuelos südlich Madrid) sowie ein Terrassenprofil mit schluffigen Zwischenlagen (Arobes bei Ribadesella) gefunden werden. Zeitlich stufen wir die Profile aufgrund ihrer morphologischen Lage sowie ihrer Schichtenabfolge und Fazies ins Jung- und Mittelpleistozän ein. Dabei gehen wir von der Basishypothese aus, daß sich in Südfrankreich und Spanien die Klimaschwankungen und die auf sie zurückzuführenden pedogenetischen Überprägungen der Sedimente ähnlich verhalten haben wie in Mitteleuropa. Unsere zeitlichen Einstufungen sind - vom Profil in Tapia de Casariego in Nordwestspanien abgesehen - als ein Datierungs-Vorschlag zu verstehen, was nicht ausschließt, daß bei weiter fortgeschrittenem Kenntnisstand eine Umdeutung vorzunehmen ist. Das Profil von Tapia de Casariego weist allerdings große Gemeinsamkeiten mit dem mitteleuropäischen Würm-Eem-Standardprofil auf. 14C-Daten sprechen nicht gegen diese Aussage. Ferner wird zur Lößherkunft und zum Transportmedium Stellung genommen. Die holozänen Oberflächenböden finden ebenso Beachtung wie die klimatischen Voraussetzungen, die bei der Ausbildung von Paläoböden im Bearbeitungsgebiet in Betracht kommen. 相似文献17.
EUF extractable nitrogen and its relation to nitrogen uptake and yield of wheat The investigations were focussed on the question whether nitrogen extracted from soils by EUF may reflect nitrogen availability for cereals. Soil samples were taken from the upper soil layer of farmers' fields differing in soil type and texture. Samples still taken in the autumn after the harvest of sugar beets as well as samples taken under cereals in January had relatively high contents of EUF extractable organic N and low contents of NO3. Decrease in EUF extractable N during spring (March until end of May) under winter wheat was significantly correlated with the N uptake of the wheat and with grain yield. In the plots not treated with fertilizer N the organic N of the EUF-extracts was as a mineralizable N source more important for crop nutrition than the EUF extractable NO3. The correlation between the EUF extractable N in spring and the grain yield of wheat was highly significant (r = 0.79***). In this correlation 20 different locations were implicated. Similar good correlations were found between the EUF extractable N and the N uptake of wheat. 相似文献
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Transformation and effect of urea – dicyandiamide and ammonium sulphate – dicyandiamide products with ryegrass and rice The transformation of urea or ammonium sulphate fertilizers both in combination with dicyandiamide was tested in soil under aerobic conditions. Nitrification was determined after percolation and different incubation periods by measuring the amount of nitrate leached. The mineralisation of urea and ammonium sulphate in the fertile soil was relatively quick. However the addition of 5 to 10 % DCD of the total fertilizer-N inhibited vigorously the nitrification for 6 weeks, 20 % DCD even for 10 weeks. In this way the danger of nitrate leaching was greatly diminished and a slow and constant release of available nitrogen rendered. After a preceding aerobic incubation (up to 4 weeks), flooding and rice-seeding diminished the nitrogen losses by leaching and denitrification remarkably in the Ha/DCD – as well as AS/DCD-pots if compared to urea or ammonium sulphate alone. This effect was particulary clear after a 4 weeks incubation period. Therefore these urea – and ammonium sulphate-dicy-andiamide products guarantee a proper and constant N-nutrition of the rice plants and may decrease the N-losses caused by leaching and denitrification. Nitrogen fertilizers with nitrification inhibitors are of special interest for rice culture, because they allow a better timing of N-fertilizer application, rice seeding and water flooding and render a more economical utilization of nitrogen fertilizers. 相似文献
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Stefan Wessel‐Bothe Stefan Ptzold Christine Klein Gerhard Behre Gerhard Welp 《植物养料与土壤学杂志》2000,163(1):53-56
Sorption of pesticides and DOC on glass and ceramic suction cups Suction cups are widely used for the sampling of soil solution. Due to sorption and desorption processes the concentration of dissolved substances in the samples may vary considerably depending on the material of the suction cups. In order to minimize these losses, a new glass suction cup was developed. In laboratory studies, aqueous solutions of pesticides and DOC were percolated through both types of suction cups; the concentration of pesticides and DOC in the percolates was examined. The pesticides pendimethaline, terbuthylazine, metolachlor and chlortoluron were tested at concentrations of 2, 20, and 200 μg 1−1. The average losses due to sorption by the suction cups were 10% (1.1—31%) for the ceramic cups and 3.1% (0—11%) for the glass cups. Sorption effects increased with increasing hydrophobicity of the pesticides and decreasing pesticide concentrations. Thus, at a concentration of 2 μg 1−1 ceramic cups sorbed 31% of pendimethaline compared with 7.7% in the case of glass cups. Corresponding tests with soilborne DOC solutions yielded comparable results. Ceramic suction cups adsorbed up to 50% of the DOC input concentration, while glass cups retarded 2.4% on average. These results are especially noteworthy because soilborne dissolved organic substances are effective sorbents and carriers for pesticides. The new type of glass suction cups may help to improve the results of pesticide field studies and, in consequence, the assessment and prediction of the leaching behavior of pesticides. 相似文献