Results 261 to 270 of about 22,175 (310)

Humic Substances and Plant Nutrition

1995
Since the studies by Liebig (1856), it is well known that plants, as long as they are adequately supplied with light and mineral nutrients, can live in the absence of the organic and inorganic structural components of the soil. Nowadays the use of hydroponics is popular not only among plant physiologists but also in certain commercial activities.
VARANINI, Zeno, R. PINTON
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Humic substances as surfactants

Environmental Chemistry Letters, 2009
Humic substances from soils and sediments can be defined as surface active substances based on the surface tension measurements. Although there are several micellar structural models of humic substances currently available, few studies evaluating humic substances as surfactants have been conducted to date.
Maris Klavins, Oskars Purmalis
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On the nature of humic substances

Eurasian Soil Science, 2015
It is argued that the isolation of low-molecular-weight compounds from humic substances does not prove their supramolecular nature, because small molecules can be sorbed on macromolecules by interacting with them due to noncovalent bonds. The relative mobility of molecular segments in humic substances has been proposed to be used as a criterion for the
G. N. Fedotov, S. A. Shoba
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THE SUPRAMOLECULAR STRUCTURE OF HUMIC SUBSTANCES

Soil Science, 2001
The scientific understanding of the molecular size and shape of humic substances (HS) is critically reviewed. The traditional view that HS are polymers in soil is not substantiated by any direct evidence but is assumed only on the basis of laboratory experiments with model molecules and ...
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Humic Substances

Chemistry International -- Newsmagazine for IUPAC, 2008
J. Lag, Amos Hadas, Rhodes W. Fairbridge, J. C. Nóvoa Muñoz, X. Pontevedra Pombal, A. Martínez Cortizas, Gonzalo Almendros   +6 more
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THE PRINCIPLES OF HUMIC SUBSTANCES

Soil Science, 2001
Two principles are presented that define the molecular nature and ecological role of humic substances (HS). The First Principle (i) accounts for and organizes an extensive body of apparently disparate data relating to the inability to purify and establish a molecular structure for HS; (ii) offers a conceptual framework for dealing with HS and for ...
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Humic substances

Environmental Science & Technology, 1982
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Characteristics of humic substance in lake sediments: The case of lakes in northeastern China

Journal of Hydrology, 2021
Longji Zhu, Zimin Wei
exaly  

Humic Substances

Soil Science, 1985
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Aquatic Humic Substances

1985
This chapter discusses the amount and nature of aquatic humic substances in all types of natural waters. The chapter contains thirteen major divisions and is the largest chapter. The major divisions include: early studies of aquatic humus, overview of isolation procedures, amount of humic substances in water, elemental composition of aquatic humus ...
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