SCHRIFTENREIHE Institut für Pflanzenernährung und Bodenkunde ...

Chapter 2 Spatial variability of soil properties affected by grazing intensity in Inner Mongolia grassland
content.
Table 2.5. Isotropic variogram parameters for shear strength on three sampling soil
water statuses in 2004.
Treatment
Sampling
soil
water
statuses
Nugget
Co
Sill
Co+Cs
Range
A0 (m)
Proportion
Cs/(Co+Cs)
R 2 RSS γ-Model
UG 79 Dry 6.84 57.60 27 0.88 0.50 78.57 Exponential
Wet 5.94 35.10 31 0.83 0.36 78.57 Exponential
Medium 1.98 14.40 40 0.86 0.73 7.29 Exponential
UG 99 Dry 5.58 47.70 38 0.88 0.48 315.90 Exponential
Wet 3.51 27.90 14 0.88 0.27 39.69 Exponential
Medium 3.78 29.70 19 0.90 0.19 21.87 Exponential
WG Dry 8.73 63.00 87 0.86 0.26 178.20 Exponential
Wet 3.60 30.60 63 0.88 0.23 10.53 Exponential
Medium 5.58 36.90 90 0.85 0.32 52.65 Exponential
CG Dry 36.00 72.90 400 0.50 0.93 81.00 Spherical
Wet 26.10 52.20 270 0.50 0.80 97.20 Spherical
Medium 3.60 27.00 75 0.87 0.19 67.23 Exponential
HG Dry - - - - - - -
Wet 6.03 36.90 38 0.84 0.64 46.98 Exponential
Medium 1.53 31.50 26 0.95 0.68 25.11 Spherical
Cs: structural variance; R 2 : determination coefficient; RSS: reduced sum of squares; -:
No data available.
3.2 Spatial distribution of soil properties in UG 79
The spatial distribution of various soil parameters and their characteristics
are exemplary shown for the ungrazed plot UG 79 (fenced for 25 years,
considered to represent the typical ecosystem conditions without grazing). Table
7 shows the descriptive statistics for all measured soil properties. The mean
contents of sand, silt and clay were 48.5, 35.3 and 16.2%, respectively. A small
standard deviation (SD) of the normally distributed data indicated that the
sampling area could be considered as homogeneous in term of soil texture. Soil
organic carbon (SOC) concentration was also normally distributed with a mean
of 31.2 g kg -1 , but had a higher coefficient of variance (CV) compared to soil
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