Search Results

You are looking at 21 - 30 of 568 items for :

  • "Solubility" x
  • Biology and Life Sciences x
  • Refine by Access: All Content x
Clear All

Dolgozatunkban a hazai Talajvédelmi Információs és Monitoring Rendszerből (TIM) származó mintaanyagban ( n = 629) végzett összehasonlító vizsgálatok eredményeiről számolunk be. A vizsgálatok célja a hagyományos ammónium-laktát-ecetsavban (AL), a 0,01 M kalcium-klorid, valamint a Baker–Amacher extrahálószerekben meghatározott K-tartalom közötti mennyiségi összefüggések és ezeket befolyásoló talajtulajdonságok tanulmányozása, továbbá annak eldöntése, hogy indokolt lehet-e a hagyományos módszer mellett új kivonószerek használata a talajok K-ellátottságának jellemzésére. Az összefüggés-vizsgálatok során az AL-K és a 0,01 M CaCl 2 -K között közepes erősségű korrelációt ( r = 0,76) állapítottunk meg. Számításaink igazolták a korábbi vizsgálatok eredményeit, bizonyították, hogy a két kivonószer a talaj tápelem-tartalékait nem azonos mértékben oldja, illetve cseréli ki. Megállapítottuk, hogy a kötöttség, a pH, a karbonátosság és a humusztartalom módosítja a kivonószerek közötti összefüggés szorosságát. Az AL és a Baker–Amacher kivonószerek összehasonlításakor a tápanyag-ellátottsági kategóriánként meghatározott átlagos dK értékek a javuló ellátottsági kategóriának megfelelően nőttek. Az egyes kategóriákon belül azonban nagy szórást tapasztaltunk, és megállapítottuk, hogy az AL módszerrel jól ellátottnak minősített mintákban is előfordulhat K-lekötődés. Úgy véljük, hogy a tápanyagszükséglet pontos becslésére szükség lehet a hagyományos módszer mellett más kivonószerek alkalmazására is. Az AL mellett, kiegészítő módszerként javasoljuk a 0,01 M kalcium-klorid, valamint a Baker–Amacher kivonószereket, mivel a 0,01 M CaCl 2 -ban oldott kálium mennyisége, vizsgálataink alapján, a növény számára könnyen hozzáférhető kálium mennyiségével arányos, míg a Baker–Amacher kivonószer a lekötődés mértékét jellemzi.

Restricted access

The traditional Hungarian method for determining soil phosphorus (P) status is ammonium-lactate acetic acid (AL) extraction. AL is an acidic solution (buffered at pH 3.75), which is also able to dissolve P reserves, so there is a need for extraction methods that also characterize the mobile P pool.

0.01 M CaCl2-P is considered to directly describe available P forms, because the dilute salt solution has more or less the same ionic strength as the average salt concentration in many soil solutions.

The amount of AL-P may be two orders of magnitude greater than that of CaCl2-P. Previous studies suggested that the relationship between AL-P and CaCl2-P was influenced by soil parameters. Regression analysis between AL-P and CaCl2-P showed medium or strong correlations when using soils with homogeneous soil properties, while there was a weak correlation between them for soils with heterogeneous properties.

The objective of this study was to increase the accuracy of the conversion between AL-P and CaCl2-P, by constructing universal equations that also take soil properties into consideration.

The AL-P and CaCl2-P contents were measured in arable soils (n=622) originating from the Hungarian Soil Information and Monitoring System (SIMS). These soils covered a wide range of soil properties.

A weak correlation was found between AL-P and CaCl2-P in SIMS soils. The amounts and ratio of AL-P and CaCl2-P depended on soil properties such as CaCO3 content and texture. The ratio of AL-P to CaCl2-P changed from 37 in noncalcareous soils to 141 on highly calcareous soils. CaCl2-P decreased as a function of KA (plasticity index according to Arany), which is related to the clay content, while the highest AL-P content was found on loam soils, probably due to the fact that a high proportion of them were calcareous.

The relationships between AL-P, CaCl2-P and soil properties in the SIMS dataset were evaluated using multiple linear regression analysis. In order to select the best model the Akaike Information Criterion (AIC) was used to compare different models. The soil factors included in the models were pHKCl, humus and CaCO3 content to describe AL-P, and KA, CaCO3 content and pHKCl to describe CaCl2-P. AL-P was directly proportional to pHKCl, humus and CaCO3 content, while CaCl2-P was inversely proportional to KA, CaCO3 content and pHKCl. The explanatory power of the models increased when soil properties were included. The percentage of the explained variance in the AL-P and CaCl2-P regression models was 56 and 51%, so the accuracy of the conversion between the two extraction methods was still not satisfactory and it does not seem to be possible to prepare a universally applicable equation. Further research is needed to obtain different regression equations for soils with different soil properties, and CaCl2-P should also be calibrated in long-term P fertilization trials.

Restricted access

. Huttunen R , Syrjänen J, Vuento R , et al.: Plasma level of soluble urokinase-type plasminogen activator receptor as a predictor of disease severity and case fatality in patients with bacteraemia: a prospective cohort study

Open access

Popova, L., Kolev, K., Stoinova, J. (1994) Abscisic acid induced changes in the polypeptide patterns of the soluble leaf proteins in barley plants. Compt. Rend. Bulg. Acad. Sci. 47 , 77–80. Stoinova J

Restricted access

soluble quaternary compounds. - Plant and Soil 70 : 303-307. Rapid assay for determination of water soluble quaternary compounds. Plant and Soil 70

Restricted access

Cloutier, Y. (1983) Changes in the electrophoretic patterns of the soluble proteins of winter wheat and rye following cold acclimation and desiccation stress. Plant Physiol. 71, 400-403. Changes in the electrophoretic patterns of

Restricted access

Current concerns about soil and water quality deterioration, limited possibility of fossil fuels, loss of biodiversity, and in general the viability of rural communities urge to work out methods of sustainable agriculture in the Nyírség region of Hungary. Sustainable agriculture seeks solutions for environmental, economic and agricultural problems at the same time. The aim is to develop new production methods which provide the protection of nature. In sustainable agricultural systems the management of organic matters and, more widely, the whole nutrient management are based on the total self-sufficiency of the farm. The entire cycle of organic matter production and decomposition takes place within the farm boundaries and makes the farm an actual biological system. The rate of metabolism and the organic matter cycle are characteristic features of each farm and define their activity for a long time. Present investigation conducted in Westsik's crop rotation experiment has found a highly significant correlation between organic nitrogen extracted by 0.01 M CaCl 2 solution and potato yield. It has shown that soil organic nitrogen extracted by 0.01 M CaCl 2 solution is a reliable indicator of nitrogen available for mineralization during the growing season. When precise nitrogen fertilizer recommendations are required, the method can supply additional information for environmentally friendly, sustainable agriculture.

Restricted access
Acta Phytopathologica et Entomologica Hungarica
Authors: S. Kribel, S. Qostal, A. Ouazzani Touhami, K. Selmaoui, A. Mouria, R. Benkirane, El. H. Achbani, and A. Douira

hardly-soluble AlPO4 with P-solubilizing microorganisms . Soil Biol. and Biochem. , 24 , 389 – 395 . Johnston , H. W. ( 1952 ): The solubilization of phosphate: the

Restricted access

). Zawartosc kolagenu ogólnego i rozpuszczalnego w miesniach szkieletowych róznych kategorii bydla rasy polskiej Holsztynsko-fryzyjskiej (Total and soluble collagen contents in skeletal muscles of different cattle categories of Polish Holstein-Friesian breed

Restricted access