Effect and potential ecological significance of the interaction of humic acids with two aquatic extracellular proteases

1995 ◽  
Vol 34 (3) ◽  
pp. 485-494 ◽  
Author(s):  
RICHARD J. DUDLEY ◽  
PERRY F. CHURCHILL
2020 ◽  
pp. 15-27

In order to study the effect of phosphogypsum and humic acids in the kinetic release of salt from salt-affected soil, a laboratory experiment was conducted in which columns made from solid polyethylene were 60.0 cm high and 7.1 cm in diameter. The columns were filled with soil so that the depth of the soil was 30 cm inside the column, the experiment included two factors, the first factor was phosphogypsum and was added at levels 0, 5, 10 and 15 tons ha-1 and the second-factor humic acids were added at levels 0, 50, 100 and 150 kg ha-1 by mixing them with the first 5 cm of column soil and one repeater per treatment. The continuous leaching method was used by using an electrolytic well water 2.72 dS m-1. Collect the leachate daily and continue the leaching process until the arrival of the electrical conductivity of the filtration of leaching up to 3-5 dS m-1. The electrical conductivity and the concentration of positive dissolved ions (Ca, Mg, Na) were estimated in leachate and the sodium adsorption ratio (SAR) was calculated. The results showed that the best equation for describing release kinetics of the salts and sodium adsorption ratio in soil over time is the diffusion equation. Increasing the level of addition of phosphogypsum and humic acids increased the constant release velocity (K) of salts and the sodium adsorption ratio. The interaction between phosphogypsum and humic acids was also affected by the constant release velocity of salts and the sodium adsorption ratio. The constant release velocity (K) of the salts and the sodium adsorption ratio at any level of addition of phosphogypsum increased with the addition of humic acids. The highest salts release rate was 216.57 in PG3HA3, while the lowest rate was 149.48 in PG0HA0. The highest release rate of sodium adsorption ratio was 206.09 in PG3HA3, while the lowest rate was 117.23 in PG0HA0.


2011 ◽  
Vol 47 (1) ◽  
pp. 97-104
Author(s):  
V. A. Medved' ◽  
P. D. Klochenko ◽  
O. V. Vasilenko ◽  
T. A. Vasilchuk
Keyword(s):  

2012 ◽  
Vol 51 (3) ◽  
pp. 228-237
Author(s):  
D. Dudare ◽  
M. Klavins

The aim of this study is to determine the Cu(II) complexing capacity and stability constants of Cu(II) complexes of humic acids isolated from two well-characterized raised bog peat profiles in respect to the basic properties and humification characteristics of the studied peats and their humic acids. The complex stability constants significantly change within the studied bog profiles and are well correlated with the age and decomposition degree of the peat layer from which the humic acids have been isolated. Among factors that influence this complexation process, molecular mass and ability to form micellar structures (supramolecules) of humic substances are of key importance.


2020 ◽  
Vol 6 (2) ◽  
pp. 64-68
Author(s):  
Nondira Khondhodjayeva ◽  
◽  
Nurmamat Rajabov ◽  

This article reveals the essence of the concept of "pheromones" and their biological significance. In the article variants of their application in agriculture for struggle against insects-pests are presented. The definition of term and classification of pheromones and their types are given: feromons of insects, feromons of fish, feromons of vertebrates, feromons of humans, fermons of plants, sexual feromons, anxiety feromons, trace feromons, epidemic feromons and their functions and significance for the representative's organism and the environment as a whole


1970 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Kishore

Palaeocene limestone of the Ninniyur Formation of the Cauvery Basin contains abundant well-preserved calcareous algae. These various types of calcareous algal seem to be controlled by the characteristics of each type environments in which they developed and thus they provide useful palaeo-ecological information of the Ninniyur Formation. The distribution patterns of these groups of calcareous algae, extending from tidal flat to reefal environments have been observed in the Palaeocene of the Ninniyur Formation, Cauvery Basin South India. Key words: Ninniyur formation, Calcareous algae, Palaeoecology. Ecoprint Vol.11(1) 2004.


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