Skip navigation.
Home
Enlightening Research

this site has not been updated since 2017... visit us @ landviser.com  to learn about new products and services!

Anisotropy of the properties of some anthropogenically transformed soils of podzolic type

Publication Type:

Journal Article

Source:

Eurasian Soil Science, Volume 42, Issue 11, p.1218 - 1228 (2009)

ISBN:

1064-2293

URL:

http://www.landviser.net/webfm_send/71

Keywords:

anisotrophy, LandMapper, podzols, soil, soil pits, theory

Abstract:

It is shown that the horizons and profiles of anthropogenically transformed soils of podzolic type—light typical agrozems, typical texture-differentiated soils developed from glaciolacustrine loamy sands and clays and from noncalcareous mantle loams, agrosoddy deeply podzolic soils developed from noncalcareousmantle loams, and agrosoddy shallow-podzolic soils developed from noncalcareous mantle loams and from calcareous loams underlain by ancient glaciolacustrine loams and clays—are characterized by some anisotropy of most of their properties. The highest anisotropy is typical of the field water content, bulk density, and total
porosity. The coefficients of anisotropy (gradients) calculated for the separate horizons as the ratios between the values of the properties measured in the horizontal and vertical directions (k= Phoriz/Pvertic) of these properties are much higher than those of other soil properties. The coefficient of anisotropy of the soil profile (K) is suggested as the coefficient of correlation between the values of a given property determined in the horizontal
and vertical soil sections. For the considered properties, K
varies from 0.4 to 0.6. For other soils properties, such as the solid phase density, the electrical resistance determined in a laboratory and in the field, and the organic carbon content, the coefficients of anisotropy are close to 1.0. The clay content has an intermediate anisotropy.
The values of anisotropy and its direction (gradient) should be taken into account upon the assessment of the soil physical properties and the processes controlling them; this is particularly important in the study of soil
transformation. The revealed regularities of the soil anisotropy make it possible to suggest a new interpretation of the data on the distribution of water and energy in soil profiles.

Notes:

Before the soil sampling in the field, the electrical
resistance of the soil in the vertical and horizontal
directions was measured with the help of electrical
probes with fixed distances between the contacts
(AMNB) (Fig. 1) equal to 2.5 cm [3].
The physical and chemical properties of the soils
were examined using routine methods and by specially
developed methods to study the electrical resistance in
the field and laboratory.
The field water content, soil bulk density, the carbon
content, the solid phase density, and the particle-size
distribution were determined in the laboratory. The soil
porosity was calculated. The electrical resistance of the
soils was determined in the field with the help of an
AMNB probe with four electrodes; it was also determined
in soil pastes placed in trays in the laboratory.

Up to now, little attention has been paid to the study
of changes in the physical properties of the soil space in
dependence on the particular direction at a given point,
i.e., to the anisotropy of soil properties in particular
loci. At the same time, the anisotropy (heterogeneity) of
soil properties has been studied at the level of soil catenas
and at the level of soil profiles in order to explain
the features of soil horizons and the character of the
boundaries between them. Such studies are performed
by routine methods of sampling soil horizons and the
laboratory analysis of the samples. No special methods
to study soil anisotropy at the point level have been
developed.
To estimate the soil anisotropy at this level of the
organization of soil bodies, special parallelepiped sampling
boxes (7.5×2.5×2.5cm) were prepared. The
sizes of the particular samples were thoroughly measured,
which made it possible to determine the soil bulk
density values in the different directions of the sampling.
Horizontally and vertically oriented samples
were taken with the help of these sampling boxes in
three replicates (Fig. 1).